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CrossBow

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  1. CrossBow
    Here at the Ivory Tower, I get quite a few requests for console services. It might be an actual repair to get a console working back to full factory function or refurbishment of a working condole to ensure it works for another 40+ years into the future. But by and large most of my requests are to enhance a console in some way. Usually through audio/video upgrades etc. But on more rare occasions, I will be sent a system that has already had work done to it either by the original owner or from another and requested to further enhance. 
    Because of just how I am... In such requests I usually undo most of what has been done before when it requires it. Sometimes I will use existing wiring and just trim it up or tighten loose AV jacks that have been installed. But in this particular instance, I had a Sears Intellivision console sent that had been prior upgraded with a composite video output and had an earlier RGB board installed into it. It was requested to give the entire system a once over and correct any wrongs found while also upgrading the current RGB with one of the newer offerings. 
    I'm writing this blog because some might feel that with a console already having been prior worked on before and semi working already, that the amount of work required to upgrade what has been done before might be less work than doing it on a console that hasn't been touched or modified in the past. In most cases... this is far from the truth as you will see with this particular Intellivision.
    First let me show you some pics of what it looked like inside when I first opened it up. I do not know exactly who did the original work, but it is pretty representative of the kinds of work I find in these systems sent to me to fixed and upgraded further.
    This is a picture of the power supply board when I first opened up the system. Nothing horribly an issue here, but it would seem that whomever was in this before did apply new thermal paste on the VRs, but they used too much as you can even see it on the legs of the VRs below. They also didn't replace out the high wattage 12Ω resistor that is the grey tube thing near the center. You can see on the left hand side it is starting to show signs of breaking down as it is starting to flake. To be fair, it might not have been this way when it was last worked on.

    This is the original composite video upgrade that was done in the past. My only issue here is that the wires these older kits from the guy in Turkey used, are a bit thin and break easy. The wiring was also not tided up and left long. Likely so the main board could still be removed in the future but some tidying would have been nice to see.

    Here are the original RCA jacks that were installed as part of this kit. Again, the wiring is left long and not secured in any way. Also, the RCAs had worked loose and were free spinning. This results in dimming picture output because the ground connection is off those metal tabs. If they jack is free spinning, that means the ground tab isn't very secure and is barely making contact.

    This is what I found when I removed the controller tray. That PCB is the older 'Fred' RGB board. It was not attached at all and was loose inside this section of the Intellivision. First, this area is NOT for installing boards like this. This area is empty because it was thought you would store the power cord inside this section when the console wasn't in use. So if someone had done that here, they very likely would have pulled something loose off this RGB board or started to fray the AC cord. Either way... this is NOT acceptable in any situation and should have been installed elsewhere in the system. 

    Because of the board laying in here loose, it stands to reason that the RGB output jack is here as well and yes it is. This isn't too much an issue but again not idea. For starters, it is a bad idea to route any AV outputs near power sources and we have that large AC transformer just a few inches away. But mainly bad because as you can see, the wiring is again loose here and would have separated easily over time. The RGB jack was epoxied into place and I do not have any issues with that since that is really the only option you have for these type of panel mount jacks and is something I do myself.

    The RGB board gets its signals from the U10 color IC chips, the same way the current RGB boards do. But in this install a separate breakout PCB was used where the original IC was removed and installed into a single wipe socket on the breakout PCB. The PCB was then stuck into the original single wipe socket that the IC chip was originally in. This seems overly complicated since it is just as easy and provides a better connection to just solder to the bottom of the PCB to the pins where this chip is located. My main issue here is the cheap single wipe sockets of the original not being replaced out with higher quality, and the use of single wipe on the PCB breakout board.

     
    Now for what I has been corrected and redone... First is the power supply board was recapped and new high wattage 12Ω resistor installed. I also cleaned up the VRs and redid the thermal compound with higher grade stuff.

    The older composite only board was completely removed as composite output was being replaced by the new all in one board combo that I installed. This is Crayon King's older v5 RGB board with one of his separate expansion boards on top. This provides not only RGB that is of much better quality and compatibility to the older board, but provides the best composite I've seen from an Intellivision, plus a really excellent s-video output as well! Here is the new RGB board combo installed on the main PCB with all the new wiring in place.

    I installed a new AMP brand dual wipe socket for the U10 color IC chip and attached it back onto the mainboard. As a result, the wiring needed for the new RGB now attaches at the bottom of the PCB to the pins that are connected to the U10 color IC chip. The scorching in the lower right is quite normal and is a result of the stupid amount of heat that the two 3906 transistors in that part of the board experience. It gets hot enough to discolor the PCB. I always replace these transistors as part of any Intellivision model 1 refurb because the originals are ticking on their last lives at this point. Can't do anything about the heat, but at least with new ones, they should last as long as the originals have to this point. The other wires from cartridge port are for a power LED that is being added to the console at the owners request. That is actually the exact same method INTV used when they added the power LEDs to the Super Pro System and INTV III consoles.

    The RCA jacks were redone using star lock washers to hold them in place more securely. I also added in an additional Red colored RCA for dual mono output so the owner of this console doesn't have to keep using an audio splitter. This also allows for a future stereo upgrade later should a nice kit come along that provides that. You can also see the new s-video panel jack that has been added since that is available, why not add it? A switch was also installed to allow for palette switching on the new RGB board since it comes with 2 different palette options. 

    Since the original RGB output jack ended up having bad internal pin connections anyway and was giving video drop outs, I had to crack out the original and replaced it with a new matching type. To help with keeping things more tidy, I used a breakout board for the jack and secured the wiring more.

    Here is what the entire rear of the console looks like at this point. Have to keep in mind that the Red RCA, the s-video jack to the right of that, and the RGB on the far right have been replaced. You can see the toggle switch used for the palette change here as well. I have it facing downwards as there is plenty of room for it, it makes it easy to find and flip and doesn't protrude beyond the normal width of the casing. I add colored boots to the switches so they don't seem quite as obvious. 

     
    And that is all I have at the moment as I'm still finalizing this console. But everything is tested and as you can see in these pics, I use connectors for all wiring that is attached to the case shell so that it is easier in the future to remove the mainboard for servicing completely from the shells. The point here is that just as much work and maybe more goes into working on a system that has already had work done in the past and it shouldn't be assumed that because some of this stuff was already in place, that it results in less labor being needed to upgrade further.
  2. CrossBow

    5200 with very odd keypad / fire button issues

    By CrossBow,


    Service Work Stories
    I've done a video on something similar to this but here is a rundown on what I was encountering:
    A 5200 sent in for services had a note stating that top fire button wouldn't work on the console. This is an issue I've run into before and in fact have created a video on it. It can be due to the controller having a broken trace of course on the flex circuit inside it. But... it can also very well be due to a faulty 4052 MUX chip inside the console located at U13 or A13 depending on the age of when your 5200 was made.
    Well, that was indeed the same issue with this 5200. But after replacing that and confirming the top fire button was now functional again, I then used my port loopback tester board with the diagnostics and was surprised when a slew of other errors came across indicating issues with the keypad. 
    I then used a different program for just testing the controllers and sure enough, whenever you put a controller into port 2 and pressed the pause button, it would call the entire aux buttons to register all at once on both controller 2 and port 1 even though a controller wasn't plugged into port 1?! So that meant Start, Pause, and Reset were all registering at the same time. I later found out that when pressing the 4,5, or 6 buttons that it would also register ever single keypad button in that same column to also register. Obviously that wasn't going to do!
    In testing the other ports, I found out that port 4 suffered similar issues but only the keypad section was messed up in that pressing 1,2, or 3 would cause all the keys on those columns to register at once. Very odd.
    Diagnostics told me it was a keypad issue so that was good. I then went to the service manual proceeded to follow the flowcharts for what might be the issue. My 'hunch' was that one more of the other 4052s was having issues. However, the flowchart kept pointing me to either a faulty GTIA (Which does handle some of the keypad controls), bad GTIA socket, or a bad 7400 chip near the RAM section. So I tried replacements GTIAs and 74ls00 chips with no change. The flowcharts have you using an O'scope to check for activity on the various triggers lines and such. Well, I was seeing activity or pulsed indicating polling that the console is doing to check for buttons being pressed, but I was seeing something else odd as well. I was seeing what would appear to be ghost pulses between the normal square wave I should be seeing.
    I proceeded to then use my multi-meter and checked all of the connection points from the GTIA to the passive components to the MUX chips to the controller ports looking for any shorts or broken traces. Everything was checking out... After hours of checking everything the flowcharts and schematics were telling me and nothing else to go on, I decided to something I should have done in the first place. Guess what that was?
    I removed each of the 4052 MUX chips (Kinda a PITA since these were all soldered to the board and not in sockets). And checked each one of them in my Bitback chip tester pro. Sure enough, I found another failed 4052 at position U12 about middle of the board just ahead of the controller ports. After installing all new sockets and putting in the original 4052s that passed and replacing U12. Finally the controllers were working proplery again and the controller loop board was passing the diagnostics!
    The moral here is that people are SO quick to blame the controllers on the 5200 for their woes. The reality, is that the 4052 MUX chips are very prone to ESD failure and fail they do...often. Especially the RCA branded ones.
    Next time you have controllers issue with your 5200. Don't just assume that controller is a POS and blanket blame it. Have the console checked out to be sure it isn't something internal causing an issue.
    The pic below shows the two 4052 MUX chips I had to replace to get this fully working again. They have little silver dots on them to indicate I replaced them and to make where pin 1 is. Again, they are highly prone to failure so if you own a 5200, best to have a full set of these on hand just in case. They are cheap ICs so it is good insurance to have on hand. In this case I have small stash of OEM RCA ones that have tested good that I've pulled from other dead 5200s over the years. I suspect in the past that U10's 4052 was changed out in the past as it was already in a socket and had a different lot number on it from the others. 

  4. CrossBow

    7800 oddity - a Maria that kinda? Works?

    By CrossBow,


    Service Work Stories
    Had a 7800 come into the ITC lab to get refurbished, and upgraded with a few things. Among the updates was to get a UAV plus mount board setup as I've been doing for over a year now.
    This is where it is important that you always...ALWAYS test the current status of electronics before you dive in and start doing stuff. A rule I didn't follow so what I discovered after putting all this work in, isn't something I could verify was an issue before the work started. I had been told that it was working 100% without issue as it was the daily driver 7800 for the owner. 
    So what was the issue I discovered? Well, after installing the UAV setup and the 10pin mini din AV connector to test the system. I saw something odd when I ran Ballblazer for burn in testing. What I saw was odd additional background graphic information on the far left and far right sides of the screen that I'd never seen before? More specific...this is what Ballblazer looked like:

    So if you look on the left and right hand side of the image, you will see what looks like the blue in the sky being extended out along with some burgundy like brown/red below that. Now oddly enough the 5200 version of the game through a UAV actually looks kinda like this, but on the 7800 this isn't normal. Here is a closeup detail of the effect and you can see it is more like a checkerboard pattern within those extra graphics being shown.

    Making matters more confusing was that NOT everything had this effect going on. Ballblazer seemed to show it the worst but any game using a colored backgrounds would have this kind of effect going on. But anything using a black ground was fine as this color hue test screen shows from the 7800 utility program:

    I did figure out pretty quickly that the issue had to be something with the Maria IC because this same effect wasn't happening on 2600 games and was only present on 7800 titles. So a few days of delay (Waiting on a new heater for my desoldering gun), I removed the original Maria IC, installed a pair of new 24pin sockets (As I don't have 48pin on hand). And installed a different Maria pulled from a parts donor 7800. And what did ball blazer look like after that?

    It worked! So yes after nearly 150 Atari 7800s that I've worked on, this was a first. My guess is that this 7800 always had this issue but as it was mainly used on a CRT and was only present on 7800 games, it likely wasn't noticed or the owner simply thought it was normal. In any event the original Maria was working in that the actual game play area on the screen looked normal otherwise. But the blanking to mask the extra graphics junk on the sides, wasn't working properly on this Maria and only by swapping it out with another was the issue fully resolved.
     
  5. CrossBow
    A 7800 I worked on over a week ago was sent to me for a 'No Power On' condition. There are many reasons for this and I have found over the years two main issues. First is simply a faulty power supply adapter. Given these things are nearly 40 years old it isn't unreasonable to think that the PSUs are nearing their end of life. In fact I've had another client send back their 7800 when it started to develop power on/off issues and found nothing wrong when they were sent back. Sure enough, it was due to a fault power supply. So when speaking to this new client about their 7800, I suggested making sure the PSU was good and if they wanted to try something quick for not too much money, to get a replacement from Best Electronics. So they did...
    However, it didn't resolve the issue 😞 . At that point it was decided to send the 7800 to me so that I could look into the issue in more detail. I honestly figured at that point it was either a faulty power switch (Because those original OEM switches are kinda crappy and get corroded internally). Or perhaps a bad 4013 flip flop IC that controls the logic for power on/off status to the system. It is basically the same circuit the 5200 uses with a few less passive components in the mix.
    So the 7800 arrived and I first tested it with my PSUs. Sure enough... no power and no amount of massaging the power button would change it either. Took the cover apart and started to look at stuff. First thing I do is short the power switch to absolutely rule it out of the mix. No dice... hmmm. I then started to check for different things off the 4013 IC. Most things checked out, but the return signal from the system back to the 4013 to indicate power status didn't seem to have any activity. According to the 7800 troubleshooting flowchart, it states to replace the 4013 IC at that point. So I removed the original 4013, installed a socket and plugged a new 4013 into place. 
    No dice... still no power. I then started to check further along and found that no input voltage was getting sent to the 7805 voltage regulator. The input voltage switching is controlled by both the 4013 and another power transistor (MJE201). The 201 stands proudly on the edge of the mainboard between the heatsink of the voltage regulator and the power input port. Sure enough when checking the readings from it, I found it wasn't switching on to send the input voltage to the original VR.
    To test this I then hooked up my bench power supply, set it to 10v and connected it directly to the input pin of the VR and to ground on the main board. Turned on my bench supply and the 7800 came to life. So I knew I had the right component.
    So... what was the point of all of this text?! Simple... to document the basic troubleshooting process I went through to identify the problem component. Now, the 201s aren't exactly made anymore but there are equivalents. However, I don't have any of these modern replacements on hand (Because this is only the 2nd time I've had a 201 go bad ever). So I took the 201 off a donor parts 7800 board and installed that. The clients 7800 lived again. 
    I also ended up replacing the original VR with a newer 2A output rated one and installed new capacitors and new front panel switches for good measure. Client figured I was already inside the system and for about $10 in parts...why not?
    Mainboard picture. New capacitors, new front panel switches, new voltage regulator and replacement MJE201 just to the right of the heatsink near the power plug.

     
    Donkey Kong PK is a good game to use for burn-in testing as it has a demo mode and uses the pokey chip for new enhanced audio. So it is a good test for everything. And... tons of fun to play too!

     
    This 7800 was cleaned up and is already back in the hands of its owner and ready to be enjoyed and played for many more years to come!

  6. CrossBow

    A 7800 that would only play 7800 games...?

    By CrossBow,


    Service Work Stories
    I'm not going to provide a ton of pics on this one because it just isn't needed. But I had been fighting with a 7800 that I've been servicing for a total of just over 12 hours in trying to figure out why it would only play 7800 games? If you put in a 2600 game, it would only give a black screen and not much else. If I put in my Plus+ cart, I could barely make out the plus cart logo on the screen as it would flicker all over.

    This told me that the 7800 was in fact switching over to 2600 mode properly or at least would appear to be in order for the plus cart to start loading up. But as you can see the picture is not correct and what you can't see in this static photo is that the image would only blink in and out quickly for me to see this. It took some doing to capture this frame on my PVM to show it.
    I first replaced some of the 3906 transistors that sit above the MARIA IC chip as I had one in the past with a similar issue and one of those had been the culprit. In the end, I ended up replacing all of the transistors on this board along with trying alternate ICs from my working test spares to isolate the issue. Nothing worked and I was about to toss in the towel and tell the owner that it would forever have to be a 7800 only console. 
    Then in checking some traces (suspecting a bad trace somewhere), I happened to touch my meter probes to two of the pins on the cartridge port and was surprised when the metered 'beeped' at me?! None of those cartridge pin fingers should be touching unless a cartridge inserted is causing a connection to do so. In looking further, I could see a dull looking color in the bottom of the far left side of the 7800 cartridge slot. I thought it was paint because it was so flat and kinda dirty looking. I cleaned and cleaned with 99% IPA and contact cleaner and whatever it was just would not clean out of the slot. Eventually I use a sharp larger end of my soldering boring tool to poke and scrape and it came loose. After some mangling with my tweezers I managed to pull this out of the cartridge slot...

    It looks like a blob of solder, but in fact it is foil tape?! It is very similar to the tape used on the 2600 switches from Atari as part of the ESD protective measures. It is all twisted up here because of my scraping on it with my tool and using the tweezers to pull it out. But yes, this little bit of foil tape had gotten into the slot at some point in time (Prior to it being send to me), and was the issue. Removing it, removed the short on the cartridge pins and 2600 games now come up and work properly again.
    The reason 7800 games would work, is because when you inserted a 7800 cartridge into the slot, it would push the pins back enough to NOT make contact with the foil tape. But with out a 7800 cartridge inserted, the pins were all grounding out. This was confusing the 7800 and so it wasn't really switching fully to 2600 mode as it should have been. Basically, it was running 2600 code in 7800 mode so the clock signals were all out of whack as a result. This is why the video output was all goofed up.
    So the lesson here, is that you always need to check power first when encountering issues with a console, but be sure to look into the cartridge slots for any foreign debris as well.
    BTW... when the console first arrived to me, this is what I found inside. It came to me in power on but otherwise non working condition. I wonder why?

  7. CrossBow

    A new 7800 project... nothing major...

    By CrossBow,


    Service Work Stories
    PCBs are designed, created, and already shipped headed my way as are a few components for me to populate the boards. I will go into more details once I have my PCBs and have been able to test and check out if my idea works the way I've planned or not. In the meantime, here is a pic of the PCB. If you are familiar with the UAV layout and install process needed for the 7800, then this should be obvious on what it is.

    While what you see here is rather large, in reality it is only about the size of the UAV board so roughly 24mm tall and about 33mm wide. Pretty small.
     
  8. CrossBow
    Received my BBPro 7800 adapter today and we have some really good things and some not so good that I'm hoping can be worked out in time.

    - First the good, is that the menu of course is easy to navigate working in the same manner
    - This might be the fastest loading flash cart for the 7800 with the exception of the older Mateos cart
    - Plays the many of the original released games without issues including both Commando and BallBlazer with properly balanced and proper sounding Pokey audio! Nice!

    Now for the issues I've encountered...
    - None of the 2600 roms I've tied to load up will work. What happens is that the 7800 resets after selecting the game and then essentially crashes. Now, I actually have a modified BIOS installed into my 7800 that was developed by Pac-Man Plus (Bob D.) and RevEng that plays the Kiloparsec build in 7800 game when it doesn't detect a cartridge installed. However, in the case of the BBPro, whenever I try to load up any 2600 game or some of the more recent 7800 home brew releases, it will default to the Kiloparsec built in game.
    - Some of the more recent 7800 home brews that I've been testing, will load up, but the audio isn't quite right on their POKEY sounds and the graphics glitch quite a bit with horizontal flickery lines.
    - One of the home brew games I have is E.X.O. in its full ready to be released form. It is a 512kb game but it doesn't load and causes the 7800 to load up the Kiloparsec built in game in my console again.
    - Doesn't seem to support Pokey at $450 or $800 which are somewhat newer implementations of Pokey addressing. So it seems it only supports Pokey at $4000and $8000 is my guess?

    Here is the list of original released titles I've had trouble getting to load up. These were all taken using Trebor's rom pack"
    - Ace of Aces will load up but no audio and corrupted graphics
    - Basketbrawl just gives a black screen and seems to lock up the BBPro since the button won't respond and requires a power cycle of the console
    - Choplifter works but has minor graphic glitching with horizonal lines across the top of the image. Seems to play normal otherwise
    - Double Dragon doesn't load up
    - F-18 Loads up but with corrupted graphics on title screen and then locks up after selecting a mission
    - Fatal Run starts up but then locks up to black screen when the demo starts or when trying to start a game
    - Fight Night stars up but the menus have corrupted text and game play graphics
    - Ikari Warriors starts up but with game play graphics corruption
    - Mat Mania Challenge will start but player sprites are corrupted
    - Mean 18 has corrupted game graphics and not really playable
    - Meltdown will give a black screen when trying to load
    - Midnight Mutants gives a black screen when trying to load just like Meltdown
    - Moto Psycho starts but player graphics are corrupted
    - Ninja Golf starts up but main player graphics are missing in the middle of the game play field and graphics corruptions in the map in the lower left
    - Planet Smashers - starts up but sprite graphics are corrupted
    - Rampage won't start, black screen
    - Scrapyard Dog doesn't start, black screen
    - Summer Games is playable but has flickery white lines on the screen only during the opening ceremonies
    - Touchdown Football will start up but then black screen when pressing reset to start the game
    - Winter Games works but has the same glitching horizontal flickering lines during the opening ceremony
    - Xenophobe, doesn't start, black screen
    So that is currently how my testing went last night with the new adapter. One of the main issues I see mainstream with the adapter, is the requirement of an additional reset wire that has to be installed using a clip off pin 13 of the 4013 IC inside the console, and then routed back out so you can plug it into the cartridge adapter. Many of Evie's adapters use and require this so it isn't new or unique to the 7800 adapter. But, I also don't see many folks willing to open up their consoles and remove the RF shielding to attach the wire and then figure out how to route it externally. Nor would they be okay with a wire dangling from their console in order to the use the BBPro. If you never planned to remove it it wouldn't be that big a deal, but then that kills the multi system aspect of having it in the first place. Evie is going to look more into trying to find ways to not require this wire, but in its current state, the adapter and the BBPro won't even load up without it attached.
    So, work to be done with it still for sure and this adapter appears to be a bit more wip still compared to the others I've gotten. But, Evie has always shown strong commitment to supporting her products and in likely short time, she will have quite a few of these issues resolved. I'll be sure to update as she updates the adapter.
  9. CrossBow

    Atari 5200 BackBit PRO 4-port Soft Reset notes and modification

    By CrossBow,


    Ivory Tower Technical Info & Notes
    The BackBit Pro multi-system flash cartridge is quite amazing in all the systems it supports and the Atari 5200 is one of the newest systems to recently be added over the past few months. One cool thing that the BBPro cart has for the 5200 side of things that other similar devices do not have, is the ability to reset the console and go back to the game folder browser without having to power cycle the console. This feature works out of the box on the 2-port model 5200s by having a selector switch on the BBPro 5200 adapter set to the 2port Hard Reset mode.

    But on a 4 port 5200, having the switch in that mode will prevent the console from booting up properly. So the switch has to be set to soft reset mode on the 4port. However, even with that switch option selected, the 4port console will NOT work with the reset button on the BBPro cart unless a very small modification is made to the console to allow for this. 
    Changes made to the  2 port main board design and later 4 port consoles allow them to work with the CX-55 adapter and those changes are also what allow the selector switch in the Hard Reset position to actually work and reset the 5200. But the earlier 4 port models do NOT have this ability. That is what I will talk about in this blog as the process to modify the older 4-port consoles to work with the reset switch is very easy to do and doesn't pose an issue with actual games so it can be left in place once done.
    What the modification does is run a new wire to an unused pin on the cartridge port that ties that pin to the reset line on the Antic IC. Turns out that Pin 28 on the cartridge port is perfect for this because that pin was NEVER designed for use with anything on either model of the 5200 and in fact isn't even attached to anything in the system. It is a floating pin on the cartridge port. As a result, it will be given purpose.
    On the 4 port model main board, it turns out that there is an unused via conveniently located near the cartridge port that is already attached to this reset line... NICE! The pic below shows you where this via is in relation to the cartridge port on the top component side of the main board. It is just to the left of the silk screen marking where pin 18 is on the cartridge port.

    And on the bottom side of the PCB, here is where that unused via is in relation to where pin 28 is located on the cartridge port.

    All that is needed is to run a small bit of conductor wire between that via and pin 28 as shown below. No traces have to be cut or anything. Just solder in a wire...simple.

    This attaches a connection from the Antic's reset pin to pin 28 directly so that it can be tapped for use by the BBPro cartridge adapter. As a result, it requires a small jumper pad to be soldered on the BBPro 5200 adapter. On the back side of the adapter, there is a DuPont style female connector attached, but to the right of that and center of the adapter board, is a jumper pad that is labeled as "Spare Reset (Pin 28)". You need to apply a blob of solder across the pads here to complete that jumper as shown in the picture below:

    And that's it! Now you can use the BBPro 5200 adapter on both a 2-port or 4-port console and have the BBPro on cart reset switch work on either model. Just have to move the selector switch to the right position depending on which console model you are using it with. It goes to the left for Hard Reset mode on 2-port and VCS adapter modified 4-port 5200s. Move the switch to the right for the Soft Reset option on 4-port consoles where you have applied the wire modification.
    I'm sure you are wondering what happens if the wire modification isn't done and you have the BBPro 5200 adapter for use with your 4port? Well that is easy to answer. Without the wire modification what happens is that the 4-port console will NOT boot up if the switch on the adapter is in the Hard reset position and it must be in the soft reset position. However, the button on the BBPro will not work properly and just crash the console requiring a complete power off/on to get it back up. Essentially making it operate like other flash cartridges that do NOT have on cart resets. It doesn't harm it to use the BBPro without the wire modification, but it does add just that more functionality to an already excellent product and is a fairly simple modification to perform if you are semi comfortable with a soldering iron.
    Thanks for reading, feel free to ask me any questions should you have any and Atari On!
    -Jesse
    Ivory Tower Collections
  10. CrossBow
    Replaced the original 7805 regulators from my atari 5200 recently and installed a pair of DC/DC switching converters in their place. In this video I show the power measurements from the original 7805 and from the DC/DC converters. Next up with be the Intellivision once I get additional parts in.


    View the full article
  11. CrossBow

    Atari 7800 - Self activating fire buttons?!

    By CrossBow,


    ITC Services Notice
    I received an A1 series 7800 main board in the mail recently where the owner stated it was working properly but was missing a pause button for some reason. Well, when I receive a 7800 system for services, one of the things I do is to pull up a test utility without any controllers plugged in. The reason for this is to ensure that the system controller ports are working properly.
    But you ask... "How does not having any controllers plugged in, help to know if the ports are working properly?" Excellent question!
    You see the TIA controls the trigger functions of the joysticks and depending on the mode the console is loaded up in, the components in use differ a little. But here was the issue with this one that might help explain things a little better...
    The issue was after powering it up without a controller plugged, it the menu selector of the utility kept selecting the first option, exiting, entering...exiting over and over. This behavior was as if the fire button was being held down. But without a controller plugged in?! Quickly using the select and reset buttons on the console I was able to get into the controller test screen and this screen was telling me that not ONLY was the first fire button being pressed, but both fire buttons were showing as being pressed down. It was showing the same behavior on controller port 2 as well. 
    Then I plug in an actual controller and.... it stops auto selecting options and now shows the fire buttons aren't being pressed. Pressing the fire buttons would activate normally. In other words with a controller plugged in, the console seems to work exactly as it should. But that doesn't mean there wasn't a problem here because technically without a controller plugged in, it shouldn't read anything at all. Plugging a controller into port 2, would also remove the condition on port 2 and make everything appear to be fine. So what is going on?
    It turns out that the 7800 is pretty sensitive to the readings it gets from the controller ports and any deviation beyond a certain point will confuse the console. To correct the issue on this 7800 I had to replace at least 2 components and also replaced a 3rd for good measure. The main culprit was unfortunately the TIA chip. Yeap... I replaced the TIA because in most trigger issues the TIA is my first item to blame and usually that is correct, but it didn't solve everything in this case. I did confirm the TIA was faulty using my chip testing as it was showing an immediate fault with the Inputs and audio portions of the chip. Replacing the TIA solved half the issue. Basically controller port 1 was working properly now, but I was still getting errant trigger readings from port 2? This ended up being due to a marginal resistor located at R35. There is a pair of them that control each of the port readings in 2600 mode that each measure 220Ω. The one at R35 was only measuring 217Ω and while that should have been good enough, it was causing odd triggering issues. When I removed R35 from circuit, then the 7800 port 2 buttons were now working properly but of course, no fire button action in 2600 mode testing. So I replaced the resistor with a used one from another 7800 donor board. This replacement measures 221Ω and is much closer to the 220 reading than the original. Installed it, and sure enough everything is working properly again. There is also a 3906 transistor in this mix and it was also replaced out as they are cheap to have on hand and I've a few. But the two main issues were the TIA and this slightly out of spec drifted resistor at R35. Here is a pic of the console where I've outlined the components mentioned.

  12. CrossBow

    Atari 7800 :- Controller remote pause function modification

    By CrossBow,


    Ivory Tower Technical Info & Notes
    This is something I've messed with on and off again over the years. After I discovered the controller pause modification you can do on the Sega Master System, it got me to thinking if something similar was possible on the 7800. And yes, it totally is as similar to the SMS, the pause line on the 7800 is always active and only when pulled low to ground does it trigger the pause. So I had played with it a bit using home made perfboard setups etc. But it wasn't really as useful or needed on the 7800 as it is on the SMS so I hadn't really invested much into it.
    For those that might not be aware, the Master System also uses a 2-button controller like the 7800, but the SMS also has a pause button on the console itself just like the 7800. The difference it that many SMS games actually use the pause on the console as a 3rd button to pull up inventory or stats..etc. in quite a few games. As a result, playing those games can be a bother when you have to get up and press the pause on your console each time you want to access those extra functions in the game. So naturally a modification for the SMS was going to come about to allow a person to add a 3rd button to their controller and along with a simple logic circuit in the console, you can make impossible controller combinations trigger functions inside the system. In the case of the SMS it is using an extra button to trigger either an Left+Right direction combo, or Up+Down depending on how you wire it up. That in turn is fed to a logic OR gate so that when you press that button on the controller it sends that impossible combination to the chip and that in turn will trigger the reset function. 
    The 7800 sharing essentially the same setup here can also be done in the same manner. However, due to the 2600 and 7800 internal logic regarding the paddles controllers; you can't use the Left+Right combo because it will confuse the console and sometimes thing paddles are plugged in. But aside from that, it is the same. 
    Consoles Unleashed in the UK sells a lot of excellent quality modification and upgrade kits for various consoles. One of those they have the most kits for, is the Sega Master System. They provide their own pause button modification kit that is really well made and looks nice. Well, I ordered up a few several weeks back and got them in yesterday. I immediately went to work on installing one into my personal 7800 as I have 2 controllers that I've modified in the past to be able to use this setup. Here is what that looks like:

    As you can see it is a tiny PCB that will fit in lots of places on the 7800 main board. Again, it is designed for the SMS but will work just as well in the 7800. In the pic above you can see that I'm getting power and ground from the bypass cap just to the right of the 6502. The Player 1 Up and Dn connections are at the top of those two resistors right next to that cap. So you have half of what you need right there in that spot. 

    Above is where the rest of the connections in my setup are going. The small blue wire that runs by itself to that single point below the RIOT IC is the reset trigger. This is an unused via that is present on every single 7800 main board revision I've see and always in this same spot. I assume it was there for testing but is also makes a great place to attach the PB pad from that board to trigger the pause function. The other two blue wires are going into cleaned out unused vias so they pass back down on the bottom of the board to attach to a similar set of resistors for the player 2 Up and Down connections. I did it this way because I didn't want to trim the RF shielding. The resistors are outside of the shielding for the player 2 controller port next to the Reset switch.

    And this is where the two wires come back through to the bottom of the PCB to attach to the resistors mentioned above. BTW, the Up and Down combo wiring attaches to Pins 1 and 2 on the controller ports.
    And that's it! Now with this in place, I can use my modified controllers to remote activate the pause on the 7800 console from either controller port.
    One thing to mention about using this kit from Console's Unleashed...
    You have to wire both controller ports! The reason is because instead of using an OR logic in this setup, they are using a NOR logic chip. As a result, the controller ports are always registering high. If you don't connect up the second set of wires, then the logic on the pause board in the kit ends up triggering the pause constantly. It needs to see that +5 from the port pins in order to maintain the logic. So if you only wanted one port to activate this, you need to use a different logic IC. Also, the kits from consoles unleashed has extra stuff I don't normally need as it comes with additional small PCBs to mount a 3rd button to and provide as a template to drill the hole into your SMS controllers for mounting it. An excellent touch to be sure, but I don't like the SMS control pads compared to other controllers and wouldn't be using them on a 7800 anyway. But they aren't that expensive and I might need those boards in the future so who knows? I might go into details on what is required on the controller side someday for this modification to work as there is work required in the controllers. I think I've covered it elsewhere online but might do that as a follow up someday.
    Here is a link to Consoles Unleashed in the UK and again, they have some excellent quality kits on hand to help modders and tech with making their projects look that more professional and easier to install.
    https://www.consolesunleashed.com/
  13. CrossBow

    Atari 7800 Powering On / Off issues...

    By CrossBow,


    Ivory Tower Technical Info & Notes
    As stated in another blog, I have a few 7800 sent to me for repairs and eventual upgrades. This 7800 had an interesting problem where as soon as you plugged in the DC power to the console, it would immediately power on and would NOT turn off. While there are a few components in the mix that can cause, this, I've found really only two components well technically 3 that should be looked into as possibilities:
    The first component and the one most people already know about, is the power switch itself. But in this particular case, it wasn't the switch as the console would still power on even with the switch removed.
    The next component is the 4013 IC flip-flop. This chip controls the actual on or off signals sent through the console when you press the power button. However this had already been replaced in the past as on this console it was mounted in a socket. Removing the 4013 did NOT change the condition on this console and it would still power on immediately. This pretty much only leaves one more component...
    There is a large transistor mounted in spot Q10 and labeled as an MJE210. These were used on both the 7800 and the 5200 that I know of. This transistor receives a signal from the 4013 telling it to actually switch the unregulated power over to the 7805 voltage regulator. I quickly found out this was the issue when I removed the 210 and the issue went away. This was replaced out using another one from a donor 5200 parts board as the 5200 actually has a pair of these bad boys on them. Here is what the MJE210 looks like. In this picture, the failed one is the green one on the mat and replacement from a 5200 has been installed into place. These only work installed in one direction and that is usually with the MJE labeling facing towards the back of the 7800.

     
    So yeah, if you have power on/off issues those are the three main components to check for first as the other components are mostly passives and not as likely to go bad.
  14. CrossBow
    I am only a hobbyist and NOT an electrical engineer. As such I'm sure my terminology and explanations of things will be off or perhaps completely wrong. As such, please let me know in comments on such mistakes as it helps me and all others who might view this video to learn.

    With that, this is my basic intro to my BK 1474 O'scope that I got some time ago and some ways it can be used. This video is only meant for fun and not as instructional as most of my other videos are. Enjoy!



    View the full article
  15. CrossBow
    In this 3 video series, I go over the basics and understanding of the Roland MT-200 sound module. It is an excellent multifunction sound module that can act as both a sequencer and sound module. This means that in addition to being a very nice general MIDI and Sound Canvas sound module, it also has the ability to record MIDI songs from the MIDI in port and save them to diskette to be played back in a standalone fashion later, making it a MIDI Jukebox as well!

    The first video goes over the basic overview of the module itself in what it is, what it can do, how to access the hidden diagnostic functions, and their uses.







    In the second video I go over the advanced diagnostic functions in how to set the internal date and time along with how to use the diskette drive functions.





    In the third and final video in this series, I go over the basic hardware needed to connect the MT-200 for use on a modern day computer. I also cover how to get the software drivers along with how to configure ScummVM and DosBOX for using an external MIDI device. Finally I demo how I have my MT-200 connected to my modern day Windows 10 PC along with my Roland MT-32 connected through MIDI Pass-thru. I then demo how I use the two modules in DosBOX on the game Space Quest 1 (VGA Remake). The audio is heavily compressed on this part as Geforce Experience software compresses the audio to mad levels for streaming. But you get the idea on how it works all the same.




    Thank you for viewing these as it has been a lot of fun learning about this wonderful sound module and understanding its uses and secrets! Enjoy!View the full article
  16. CrossBow
    Not a video to share this time, although in hindsight I should have made one as a quick tech video. But recently I decided I would get some replacement filter caps for use in standard wall wart power supplies like those used with our Atari, Sega, etc. consoles from back in the day. As I have quite a few of them on hand and wanted to test them out I decided to start with a few Sega Genesis power supplies. I decided to look at three different supplies last night. I first checked the voltages from all of them and they were all pretty normal. One reading about 14v, a model 2 supply reading 13.5, another model 1 reading about 13.8v. Nothing out of the ordinary from such old transformer supplies that don't have a load on them. Still, they are all well over 20 years old so I figured why not.
     
    Now, many of the sega power supplies require a small 4mm hex bit to open them up and that was the case with one of the model 1 supplies I had. I didn't have this tool so I ordered it online. The other two I had actually required a small #5 security torx bit similar to what is used on TurboGrafx and PC engine systems. But that bit I had on hand and with that I was ready to crack them open and get to work.
     
    The first model 1 PSU is one I've been using for a few years on my workbench as a go to PSU for several systems. I've created adapters so that I can use it with several other classic consoles I work on so I don't have to keep a bunch of different ones on hand at the ready. So it has gotten quite a bit of use over the past few years. It required the small 4mm hex bit I had to order. No issues once I got it opened up. Looked okay and had that ages electronics smell but nothing out of the ordinary. Removed the old large 3300µf at 16v capacitor. It seemed to be in good shape still with no evidence of bulging or leaking. Still it is over 20 years old and would hurt to change it out. Did that and working just dandy!
     
    Then I looked at the second one and this one is where I first discovered that the 4mm hex nut driver I'd gotten wouldn't work and I needed to use my #5 security torx instead. Opened it up and it noticed it seemed to be glued shut as the two halves wouldn't separate as easily as the last one had. Interesting..worked on it a bit and was able to get it to come loose on one side. It was right about when I started to grab for a small flat blade screw driver help pry open along the sides that the smell hit me... 
     
    If you aren't aware, the old electrolyte used in these older caps smells very much like fish and has an oily consistency to it. And it is very distinctive and not at all like a normal electronics type smell. This wasn't a good sign as that smell would indicate that I was about to discover something nasty inside. Once I got the two halves of the PSU case apart, the smell really hit me and I could see it. A shiny surface on the top of the small PCB around some of the diodes on the PSU and where the output wires are soldered in. I removed the PSU assembly from the case housing and this is what it looked like on top.

     
    Now it is hard to see, but you can make out the shiny look on the PCB and also where it is a darker color. But the large filter cap looks okay physically right?

     
    Well not quite because once I removed it you can see near the negative lead of the cap, where it has stained the PCB from electrolyte that has been leaking from the capacitor over the years. Also hard to make out but the bottom of the cap itself was also coated in the oily residue of the leaking electrolyte. Now this doesn't seem like a big deal right? Just clean that off and put in a new cap and your good to go? Well, the bottom side of the PCB where the traces are, has a very different story to tell and shows you the results of what leaking electrolyte does on a PCB over time.

     
    Here you can see where there is a mottled almost moldy look the left half of the bottom of the PCB here. Well, that is where the cap was and where the electrolyte over time has seeped onto the bottom of the PCB and started to corrode the upper layers of the PCB masking and copper traces under neath. This is essentially cancer on a PCB slowly eating away at the board. If this had been something with much smaller traces to components, it would likely be a lost cause or at least require quite a bit of small and time consuming trace repair work. Luckily the traces on most PSUs like this are large and thick. So how do you clean this up? I took my electrical grade 99.9% alcohol cleaning solvent and a toothbrush and went to work to clean and neutralize the electrolyte. In the process of this, the top green layer coating started to flake off exposing the copper traces underneath it since the electrolyte had so badly ate into it. There were also dark patches on the copper itself underneath. This required me to also use my fiberglass pen to remove the remaining layer protecting the traces to fully expose them and also remove the corrosion. This is what it looked like after cleaning and removing most of the corrosion.

     
    Still a few dark patches left behind that has pitted into the copper traces but it shouldn't get any worse than it is now since it is cleaned up. So what now? Well I installed the new replacement filter cap and the used lots of flux and solder to apply a new layer across the traces to protect the copper underneath going forward. This was following up by a lot more cleaning with both a PCB board spray cleaner and lots more high grade alcohol. I then left it out overnight exposed to fully dry out before testing and reassembly.

     
    The third PSU was for a model 2 genesis and also required the #5torx security bit to open it. It was like the first PSU in that the capacitor in it wasn't leaking and everything appeared to be fine inside. Just replaced that cap the same way as the first, buttoned it back up and it works just fine. 
     
    But the moral of this is that just because a power supply works, doesn't mean that everything inside it is okay and good to go. That second PSU with the leaking cap would have eventually died on me as the traces would have continued to corrode and eventually sever from the rest of the circuit and possible start to lift from the PCB itself. This means that with this wonderful discovery, I need to now try and open up all other PSUs that I'm able to open up easily and inspect them for similar cleaning and possible repairs.
     
    View the full article
  17. CrossBow
    I bought this kit a few months back as a pre-order and had to wait since I wanted a different colored shell. But the kit allows you to use a donor GBA mainboard from a standard GBA and essentially turn it into a small console to play your games on a modern big screen display using an SNES controller. Here are thoughts on this:
    The small ribbon cable that has to be soldered to the GBA CPU is tricky and requires a lot of patience to get soldered into place. The pitch of the soldering is quite fine and I had to use my 10x loupe to verify the connections and check for and remove any bridges I found (There were quite a few). The ribbon cable is designed and marked to help you line everything up. It has a nice center GND you solder down at the corner of the CPU to help anchor the ribbon in place. There are also markings showing where pin 1 and pin 127 should be lined up. However, the first time I tried this, I actually had the left hand side of the ribbon where pin 127 is one pin off. Due to the way this ribbon is designed it is possible to have one side perfectly lined up but the other side be too high or too low allowing for a 1 pin offset as I had initially. No damage done as it just meant my controls weren't working initially. But it did require me to carefully undo and remove the ribbon completely so I could clean up everything, re-align it and do it again. This picture below is of the final and successful placement of the ribbon on the CPU.

     
    The kit comes with a 3d printed case shell. You can choose from the colors they already have on hand and available if you are in a hurry or you can specify the color you want. I do have to complain about this part because they don't list all the colors in their order page and only stated that with a custom color, you specify. However, there isn't a comment section or anything in which to specify this?! What I did and apparently this worked, was when I made my payment via PayPal for the kit, I specified that I waned a purple case shell if possible otherwise red would be good. But again, they didn't have a list of the colors they can do anywhere so I was guessing they could accommodate my choice. They did as do have a purple case shell for my kit. The fitment of the case was great as it initially arrives already pieced together without the screws in its own bag. However, once everything was assembled I found quite a few issues. For one, the GBA mainboard doesn't line up flush with the edges of the case shell so everything is recessed inward about a 1mm or so. This isn't a huge problem, but it doesn't look as finished as it could. The holes on the inside for screwing everything down into place doesn't allow for any adjustment so it is what it is. I also found that the openings for the ports on the back are a tad on the too small side of things. But since it doesn't sit flush anyway, this doesn't matter that much. It did come with two power buttons I can choose from. A grey solid printed button, or a white semi translucent one. I chose the white hoping it would allow the LED on the GBHD board to shine through. Spoiler...it doesn't.
     
    However, the main GBHD FPGA board does seem to sit more flush with the front side of the case so there is that.

     
    The sticker comes in the kit and is an optional thing you can apply. I sprayed off the top of the case with some 99% IPA to make sure it was a clean surface before applying the sticker on mine. I think I got it lined up pretty well for eyeballing it.
    So...what about the output and overall thoughts?
    To sum up...it is outstanding! The way the kit works is that the GBA main board is only used to provide the logic for reading the game and handling the controls. The LCD driver on the GBA main board is what is providing the video output to the GBHD FPGA board that provides the final output. As a result, you remove the battery terminals and the speaker off the GBA main board as they are NOT needed and take up additional space. In fact, on some of the other GBA console kits, you have to make sure to put the GBA power switch in the on position, but because of the way this kit work, it is providing voltage directly to the CPU when you power it on. As such, the power switch and volume wheel have no use or function anymore since all of that is bypassed. In fact, the audio comes straight off the CPU pins and is handled by the GBHD board itself. In a nutshell the GBHD FPGA board is really doing the heavy lifting for the video/audio output and as the interface for the controller input on the front. Audio is an issue for some as I've been told it isn't compatible with all setups. This is because the audio appears to be handled as PCM analog through the HDMI and I guess newer TVs and AV receivers don't support that? My AV receiver in the game room is 10 years old and not only does it support PCM audio, but supports up to 96khz PCM so I had NO issues with this on my AV setup.
    Once installed, the kit allows you to pull up a simple to use OSD for changing a few things on the video display. It defaults to output at 720p and this is really the most compatible and best looking option as it provides about a 4x scaling from the GBAs original resolution. It has different modes to control the aspect of the image from proper integer scaling (Default) to stretching to fit your widescreen or a setting of in between with a little stretching and some minor borders around the edge. It has an option to compensate for overscan and this was needed on my TV in the lab area but not required on my main TV in the game room. You can also choose what color you want the border to be if you so desire. There are options for LCD grid like effects and scanlines. These look okay but I'm not a fan of either when playing on my big screens. There is also some filters but I honestly think they made the output look worse on my modern TVs. My guess is they are there to help provide a better look if you use this with other equipment to play on a CRT but that is just a guess. My kit came with Firmware v4 pre-loaded and apparently was assembled back in June of this 2022. I do see via where something like a jtag header could be soldered in but do NOT see or know of a way to update the firmware in the future. It might be possible this is something that could be implemented in the future using flash carts? But that is only speculation.
    How does it look? Well here is a quick 1min video of it in action with the game Iridion II since I had that handy for testing. I used my phone to get this so it isn't direct capture but you get the idea.
     
  18. CrossBow

    IMP TIA = BAD TIA!!!

    By CrossBow,

    Had a pre-modded 7800 sent to me with a UAV that had good s-video but was producing some ugly jail bars in composite. But it was ONLY doing this on 2600 games. I at first suspected something in the wiring of the UAV or the UAV itself and first redid all of that and replaced the UAV. No change. It was then I started to look at things more closely and noticed that this '84 main board all socketed chip board appeared to have a TIA I'd not seen before. The company branding on it is IMP and it had a mid year 1988 date stamp on it indicating it was not likely original to the 7800 to begin with. Since I was able to disconnect the TIA color signal and get crystal clear black n white with the jail bars, I knew it had to be in the color signal. And since the UAV is tapping that signal straight from pin#9 off the TIA there was really only one culprit. I had another semi working 7800 with a more normal looking AMI branded TIA on it. Pulled that and put it into the socket on this troublesome 7800. Sure enough the jail bars are gone! I'm guessing this is a late revision TIA and it likely a CMOS part as it doesn't seem to heat up like most TIA chips do and it just feels a bit different. In any event...stay the hell away from these TIAs in and think about replacing them if you find them in your 2600s or 7800s. Especially if you plan to use composite upgrades or a UAV as it does produce jail bars. I also noticed that color trimmer has to be adjusted but a full 180 between the two chips. So there are some obvious internal differences in how they are designed and made. I've attached some pics to show what I was getting and between the two TIA chips.
     
    Here is the section about halfway on the edge of the ColorMatch screen on the Colorbar generator program. You can see the jail bars on the slightly different hue of green on the lower half. Upper half is fine.

     
    Here is the green purity screen with the bad TIA. Again, you can see the jail bars and while this is on green, they are present on all colors pretty much.

     
    Here is the colorbar screen from the bad TIA IMP branded chip. Again you will see that most of the colors exhibit noticed jail bars on them. It is quite distracting and unusual to see from a UAV board.

     
    Here is the actual IMP branded TIA chip that was causing the headaches above:

     
     
    Now here is the colormatch screen edge with the good AMI branded TIA chip.

     
    Here is the green purity screen with the good working TIA. Quite a difference here.

     
    Here is the colorbar screen on the AMI TIA. While there is still come color bleeding and other artifacts normal with composite on an LCD, you will see that the colors don't have the jail bars as they did with the other TIA chip.

     
    And of course, this is what the common AMI branded TIA looks like in most 7800s I've encountered:

     
    So if you have nasty jail bars from your composite video out signal, you might look at the TIA as the possible cause.
     
    Ivory Tower Collections
     
    View the full article
  19. CrossBow

    Installing a UAV into a heavy sixer

    By CrossBow,


    Service Work Stories
    The process to install the UAV into a heavy or light sixer is pretty well known and documented. In summary you basically set the jumpers on the UAV for the 2600 setup and then solder a socket ontop of the 4050 IC chip and header pins into the UAV and plug it into the socket. Job done... 
    However, there is a caveat to this method that doesn't become apparently until you find yourself moving consoles around a lot. And when I mean moving the consoles, I mean as in them being packed up, stacked up, put away into storage, shipped about...etc. Or let us say...for convention use. What happens is that all the jostling and movement of the console overtime will cause the UAV to walk about of the socket and come loose. Once this happens, the socket is essentially worn out and it will have more often. The solution is to direct wire solder in the UAV to alternate points and then affix the UAV in a way that isn't as likely to come loose over time.
    The solution I came up with recently, was to use the empty space on the PCB where originally Atari had planned to install a built in game on the console. There is space and markings where a 4k ROM would have been installed on the sixer PCBs for this purpose that was never used. So that provides a nice flat area to attach the UAV with double adhesive tape or what I use which, is 3M Dual Lock fasteners. Basically plastic industrial grade velcro like reels that can hold up to 10LBs of weights supposedly before coming separated. More then enough for a little ole UAV. The adhesive that is used on the Dual Lock stuff is also crazy strong if you clean the surface well before hand. To attach to the UAV is trickier because the UAV doesn't have a smooth surface on it that is really large enough. This is due to the UAV having components installed on both sides of the PCB, plus the wiring etc that is also needed. To help get around this, I've been buying 3/4" shrink tubing that I can get very cheaply locally and sliding it over the UAV after my initial wiring to it is done to provide me with a much smoother and consistent surface area for the other dual lock velcro to attach to. This install required the use of the basic version of the UAV that doesn't require jumpers to be set as it is all direct wire.
    The wiring on the sixer might not be consistent across the heavy and light as I only had this heavy on hand currently. But it turns out that 4 of the 5 connections needed for the UAV can actually be wired and soldered to empty unused vias on the main board. Even better, is that these alternate vias (I think they were test points), are very close to where the UAV sits and provides some pretty direct runs keeping everything nice and tidy. The pic below shows three unused vias right in a line above the disc capacitor marked as C210 on the board. From left to right these vias connect to TIA pins 2,7, and 8. If you look at C210, you will see an unused solder pad directly right of it. It is between the markings for C210 and R208. That is where you can tap audio from as it is directly connected to pins 12 & 13 off the TIA. You will see another unused via just off to the side of R214 below. That connects directly to TIA pin 5. Finally, you need a connection for the TIA color signal. That can be had easily from soldering a wire to the right leg of R212 as oriented in this picture below.

    Now, something to keep in mind is that on these older 2600s and on later 4 switchers, (possibly the jrs?). Atari would add in an 800ish  Ω resistor to help with color saturation. However, this resistor will cause the colors to look way off in most cases through the UAV and has to be removed from the circuit. It is located essentially between the pin 6 and 9 positions below the TIA chip on the main board at location R213. What I usually do is to just de-solder and lift the right leg of this resistor as that is also tied directly to pin 9 of the TIA. So you could use this solder pad for the color signal as well but it would require a longer wire to route down there.

    Power and ground can be had from several places. I ended up using one of the unused vias for the non-existent 4k ROM for ground. Power was possible from here also, but would have been in the way of my UAV board installing nice so I took the +5v off the bottom leg of R207 just left of where I placed the UAV. Again these points were chosen to keep all wiring to short runs. Shorter wires help with minimizing signal loss and keeping the UAV board in place over time.
    And that is pretty much it. I should also mention that if wire length isn't a concern, then with the exception of audio and the power and ground connections, all of the other points mentioned can also be tapped from the resistor legs mounted below the TIA. I don't recall which is which right now, but I know that all of the TIA connections can be had from them also. Just requires longer wires to route around the TIA to those resistors. It is also possible to mount the UAV on the bottom of the pcb using strong double adhesive tape and then just solder the wires directly to the legs of the TIA. But you would have to make sure you are using the basic version of the UAVs for such an install and it would require likely drilling a hole on the side of the RF housing box for your output wires to come through. You will see in the overview pic below of the UAV installed, that my output wires go under the cartridge slot and out the back. That is because the housing has some thin slot openings on the top and bottom allowing wiring to come through. It might require having to file the metal down a bit to opening the gap but might not require it depending on how the housing for the 2600 was done.

     
    I might create an install video that essentially tries to cover UAV installs in the sixers and 4 switch units in the future as a single all in one video. While solder points are varied across the different revisions of the console, there is enough similarity that I think a single install video with pauses and different sections for the different revisions is possible. Have to think about that...
     
  20. CrossBow
    Been doing a few composite AV mods on client intellivisions. Though I would video the process I go through for doing a capacitor replacement. I'm working on trying to get the videos down to be more watchable in smaller amounts of time but perhaps too much compression on time is used in this video?
     
    Big special thanks to Adan Toledo for his permission to feature some of his music from the CollectorVision homebrew release of Sydney Hunter & the Sacred Tribe for the Intellivision!
     
    - Order your official OSTs for Sydney Hunter and Mecha 8 from Adan himself here: http://adan.eu5.net/europe.html
    - Order your copy of Sydney Hunter & the Sacred Tribe plus other homebrews from CollectorVision here: http://collectorvision.com/
     
    Comments always welcome and much appreciated!
     

    View the full article
  21. CrossBow
    Seems to be lately that I'm getting in more and more Intellivision consoles that all arrive with the same similar condition. Basically what most might call a black screen when powering on the console but it is more like a dark grey screen with a few lines along the bottom of the screen of even lighter grey. Pressing the reset button does produce a full black screen that will flicker and come back to the same dark grey screen or sometimes it might do something different like an all fuscia colored screen or yellow for instance.
    In all cases, it basically means that some IC chip or component in the chain of the IC logic has failed and the Intellivision isn't able to boot up properly as a result. You can pretty accurately simulate the effect by simply powering on the console with out a cartridge. Same thing will happen when you pull one of the main ICs out of the console.
    But how to troubleshoot it and fix it? Well, honestly the service manual for the model II actually has a decent flowchart but even that still doesn't quite cover everything. So I wanted to share my experience on what I now basically do whenever I encounter this condition:
    - First is to absolutely verify that all the voltages are present to the main logic board. The service manual will have you test the voltages on the power supply board internally sure, but you can have a bad connection on the ribbon cable to the main board causing voltage to not make it to the main board properly.
    - If the voltages check out, then the first actual component to swap out is usually the STIC IC chip (Standard Television Interface Chip). It is one of the several large 40pin ICs that exists in both model 1 and model 2 consoles. Near as I can tell their aren't any differences between the ICs of those two models with the exception that the STIC on the model 1 has a heatsink attached and the model 2s don't. But they can be swapped interchangeably. Although the heatsink on the model 1 STIC will prevent the top case from closing properly on the model 2 console. So you have to be sure the chip is bad as you have to solder it directly to the board for it to all fit.
    - If that fails, then I usually will try and swap out the CPU IC next. Although honestly the CPU seems to be a tank in the Intellivision. 
    - Next up on the model 1 consoles is to look at replacing the pair of 3906 transistors that stand up off the board in the area just above where the CPU sits. Can't really miss it as they get so hot that the board is usually discolored around their solder points. But again, as they get really hot, they do burn out.
    - From here I then grab my frequency counter and verify that I have a proper master clock signal all the way to the cartridge port using Pin 10 to test that signal. Though rare, I have had a crystal that was bad in one and a bad variable capacitor C2 in another that I found by checking the master clock frequency.
    - From here it gets much less straight forward and will require having to break out an O'scope to start looking for various signal waveforms as per the service manual to try and help isolate which component might be at fault. 
    Now in not so common fixes I've done to correct for this same issue.. or corrupted graphics.
    The cartridge port...yeap. The games themselves complete some of the signals in the logic so if a game isn't present or the port has bad connections and isn't making good contact with the game cartridge, you will get the same black screen (dark grey) screen condition
    And I've also had the Hi and Lo graphics rams cause a similar issue although in the cases of those chips going bad, the games will usually load up but look like they are missing sprite data in a way that looks like how NES games look with a bad 72-pin connector where the you have lines of missing graphics or corruption on the screen. Depending on the when the Intellivison was made, it might have a pair of 3539 ICs located in the upper left of the main board with the orientation of the cartridge slot on the center right. They are labeled U7 and U8 on both model 1 and model 2 consoles. At some point a main board design was made and they might have a pair of 2114 ICs there instead. All of the model 2 units have 2114s for the Hi and Lo video RAM and it is located in the lower left portion of the main board on the model 2. 
    So... there you go. A few things to check out in the case of a black screen non-working Intellivision console. I will say that while more complex in components and IC chips, the model 1 units seem to be a bit more robust in regards to operational use vs the model 2. However, the model 2 cleaned up the power delivery quite a bit and tend to usually have a better RF output while being a little simpler on the inside component wise.
     
  22. CrossBow
    So as the title states, I'm temporarily suspending my console services for repairs, refurbs, and upgrades until about the fall timeframe. This is to ensure I have plenty of time to work on a large project that has a strict timeline. Anyone that has already sent their systems to me will still receive their service requests and will take priority to get them done quickly. But for others, I'd rather hold off and have them wait because I'm not comfortable with my client's systems sitting at the ITC for what could be a few months.
    I do apologize for those that might have been holding off and wanting services done, but rest assured I will be able to provide services again in a few months to the general public. Thank you for your understanding and if you have any questions, do feel free to contact me.
    -J. Hardesty
    Ivory Tower Collections
  23. CrossBow

    Just a simple but kinda cool project?

    By CrossBow,


    Ivory Tower Technical Info & Notes
    The 'Tower' was without power most of last week due to powerful storms on Father's day. As a result it put me behind a bit on console services and projects. Well last night as I've been working kinda constantly on console stuff to try and get caught up, I took a break and decided to do something I'd been meaning to try and implement for a while now.
    I'm sure many of you here are aware of the Atari Vox? In summary it is a small device that plugs into controller port 2 on the 2600 or 7800 systems to allow you to save game scores and can also provide a means for speech to be played back in games that support it. Very cool device but it has one annoying thing about it. That is the fact that the audio from the Avox is separate from the rest of the system so you either have to plug in a set of external speakers or as I had been doing, I would use a 1/8" to RCA cable and plug one of the RCA jacks into one channel (usually the right) on my AV receiver audio input and the 7800 audio out in the other channel. Or, you have to use an external audio mixer to combine the two into one. None of that is really elegant so I thought of a simpler way to go about it. I'm sure you can see where this might be going?
    So the 7800 especially is a little unique in that it was designed to make sure of an external audio input from the cartridge port. Typically POKEY enhanced games use this for audio. The basic mixing for this in the console is to tie the TIA audio coming in internally from the console's TIA chip and the POKEY audio from the external cartridge audio input line with different resistors for each to balance their signal so that one doesn't overpower the other. Well, why not simply add in a third audio line into that mix with a resistor to also bring it down in level?
    That is exactly what I did as is demonstrated in this video...
     
    I have some pics I can provide for those interested but in a nutshell I installed a separate 3.5mm audio jack along the back of this test 7800 I have in the ITC lab and instead of if providing audio output, it is used as an audio input and is part of the mix along with the external audio and internal TIA audio. This allows for all three to be used at once and have all the audio could out through my normal audio output RCAs I have installed on the console. 
    No separate speakers...not Atari audio from just the Left with the AVox speed only on the right. It is all properly mixed together in dual mono as I would prefer. I will next do the same on my actual daily driver 7800 where this would be used most, but I'm glad to have it on my lab 7800 as well. The way this was done, should also be possible on a 2600 and I might very well explore that on a 2600jr I also have in the lab. 
    I know this isn't the first time something like this has been done as I've seen other projects where owners have embedded the AVox completely into their consoles and then with a lot of wiring, use a switch to enable/disable the Avox as needed. But I was looking for a more simpler solution that would still allow the AVox to be used with multiple consoles and not be gutted and dedicated inside a single system and yet still easy to use without a lot of extra wire and mess. One small headphone to headphone patch cable is all that is needed now for this when I want to use my Avox.
    For those that might want to try this on their own, know that a limiting resistor is needed as running the audio output straight in from the AVox is likely to sound messed up/distorted and would cause audio cut off on other audio sources trying to play at the same time. I used an 8k resistor in my test here but I think anything between 6.8k - 10k would suffice. I would also start with your volume pot on the AVox set to about the 1/3 volume level and then play a game that uses both speech and other audio at once to dial in the volume on the Avox until you are happy with it all.
     
  24. CrossBow

    Latest stuff at the ITC

    By CrossBow,


    Service Work Stories
    I know I've not made a video in a very long time on my ITC Youtube channel. But I figured I would mention here the latest things happening at the 'Tower'. Just because there haven't been any vids uploaded, doesn't mean there isn't something always still going on.
    First is that console service requests have picked up quit a bit for me over the past 2 years. It really started during the pandemic, but then larger and larger service requests started to come in since and at this time, there is pretty much always a console or 3 at the 'Tower' waiting to get serviced it seems. When not working on enthusiasts game consoles, then I use that time to work on my own consoles to improve old install work I did in them (Some going back over 10 years ago). 
    Well, currently what is at the ITC to be serviced is essentially done and will be getting shipped out soon, but as we had some pretty inclement weather come in this past Sunday and as a result our offices were closed at my normal day job yesterday. I spent the time to finally design some new PCBs for use in my services. One isn't that big a deal but is my own pcb breakout for use with 9-pin mini din connectors. I've got an old gerber file set that I either found a few years back or was sent to me that I've been using. But decided to make my own with some slight alterations on the design I'd been using. Not a big deal so not really anything to show there.
    But, I also finally designed revision 2 of the 7800 mount board. I already had another slight revision that I was calling r1b for the past 6 months but decided to just add in one new feature to make it easier in the future as I'm now getting requests for it. The new feature is adding in an optional audio input pad with resistor onto the mount board that can be used to mix in a 3rd audio input source into the 7800 setup so that it along with the normal audio can all be heard from the RCAs or whatever is used for the audio output on the console when upgraded. I'd been doing this manually by just adding in a resistor in series on separate wiring that would then get soldered to the + pad on the output filter capacitor. It works but I like how this will look better and I don't have to hide a resistor to solder in place anywhere and can just run a wire straight off the pad to the jack used for audio input.

     
    The other project I worked on yesterday was to finally design a new mount board setup for use in the Intellivision RGB installs. I previously designed a small mount PCB about 2 years ago for this and that will still be needed and used in some circumstances. But more and more lately, most of my clients have me remove the RF modulator and install the mini din jack there for the RGB output. This is because with a PCB of the right height, you can place the jack here without having to cut the case. The current PCB mount is kinda difficult to install as it requires a lot of heat to ensure that the solder seeps it way under the PCB and has always been a little smaller than I'd like to help provide the needed anchor and support for the mini din. Well, after installing a few other difficult kits into consoles designed by others, I decided to adapter something similar. This new mount is larger and uses 2 of the original intellivision RF anchor holes that I run clipped leads through some vias to solder the mount board into place easier with less heat and possible provide a more secure mount as a result. It does actually use a 2 PCB setup to achieve the height needed but I've found that 2 PCBs in a stacked configuration is still going to be much easier and cheaper to have made. The older mounts were 2.6mm thick PCBs and as a result, they weren't cheap to have made. Using a 2 board solution will also similar results with less cost. I will be refining this further. But this is the top PCB that the mini din will fit into the lower right corner section and then be held in place with solder along the two large ground planes along the left and rear of the jack. Both PCBs feaure hashed ground planes to help with strength. The top logo and wording on this PCB are now silkscreened but in fact are done by removing the solder mask over a copper filled section of the PCB. This way the logo and words have a shiny look to them that is actually part of the PCB and not just silkscreen that can wear/rub off.

    So, yeah all of these and other parts on order now and I'm excited to see how it all looks and works first hand.
     
  25. CrossBow

    Loctite and ABS = Gallium and Aluminum...

    By CrossBow,


    Ivory Tower Technical Info & Notes
    So over the past few months, I've been trying to find ways of making the RCA jacks that I install into consoles more secure so they don't free spin over time. What I've been doing in the past that actually works 90% of the time far as I know...is that instead of using the small lock ring washer that typically comes with RCA jacks, I use inner star washers of the right diameter to do the same thing, but with more points of contact to lock into the plastic. It also has the advantage of holding the securing nut in place tighter as well since the inner teeth of the washers are present on both sides of the washer. From there, I've used light amounts of epoxy to help hold the securing nuts fast in place as well. 
    This has worked well for years but recently I did have some consoles start to come back where one or more of the RCAs had still somehow managed to work loose over time. So this got me to wondering if there were other methods I could employ. 
    Enter the idea to use Loctite or something similar... Hang tight...there is some history I have to talk about first and a lot of details to follow. Grab a snack and drink and settle in...
    Now there are two types of loctite that you can get for threading applications. One is the red colored stuff and is essentially permanent in that it is very very difficult to remove nuts off their threads if that stuff is used. The other is the blue kind that still allows the parts to be separated (Although not nearly as easily as without...). So I decided to try the blue stuff.
    Now I will say that sure enough the blue loctite holds really well. It basically is a liquid that once exposed to air begins to congeal and turn into a rubber like substance. As a result, it acts as filler between the threads of the nut and the jacks you are securing together. It does still come undone but requires a lot more force to do so and actually squeaks while you remove the parts after it has cured. So it does its job... but... there is also a warning on the package that I did read but didn't think would be an issue in this case.
    The warning says not to use with plastic threaded parts. So I assume this meant not to use it with plastic bolt/nuts sets commonly made of Teflon and the like. Well... I'm here to tell you that isn't the only issue.
    Over a month ago, I installed a UAV into an 800xl. The owner requested I install a separate standard 4pin s-video jack in the opening that the RF modulator used to occupy as the opening is nearly the exact size needed for one style of s-video jacks I have on hand. But they also wanted a pair of RCAs for audio to be installed. They didn't want to purchase an Atari monitor cable specific for this hence the request for separate jacks. So I drilled in the needed holes and got the jacks line up great! To install them, I used a bit of the loctite on the threads of the RCA jacks and proceeded to tighten everything up as normal. I then set the case shell down for about an hour while I recapped the main board and did other things. When I picked up the bottom shell housing I was horrified to see that a long crack had formed between the two RCAs that ran beyond top to bottom of the shell?! I removed the RCAs and discovered that around the holes where the jacks had been installed, there were small spider cracks around the openings and the plastic appeared to be much more brittle than I remembered? So I cleaned everything up and applied some epoxy across the cracks on the inside of the case shell to restrengthen the area and prevent any further cracks from occuring. I let it cure for about 2 days before reinstalling the RCA jacks. This time as they already had the loctite on them, I didn't apply anymore and just had to crank down a bit more to tighten them back up. This time I left them a little more loose than normal and then applied more expoxy over everything to make sure it all held tight. And this worked fine as expected.
    My thinking at that time was that I had simply tightened the nuts on the RCA jacks too much and it caused stress fracturing in the plastic that spread out. Didn't think much of it beyond that.
    Last night while working on a 5200 (A console I've done this work on a LOT of times), I drilled in the holes on the expansion plate as normal using a template I've had for years now. Installed the RCAs and again used some loctite on the threads to secure them nicely in place and then set it aside for about 30min while doing other things. I picked it back up to solder the wiring to it and again was horrified to see a crack had formed vertically between two of the RCA jacks?! I was like, what the heck?! I've done a lot of these 5200s and the expansion plate has never done this before? When I started to remove the RCAs to inspect, the entire thing just started to crumble in my hands like dirt. Sure enough the entire plate had become super brittle and was falling apart in my hands?! At this point I was pretty sure I knew what was happening and decided to test on another piece of similar plastic. Scratched it to expose the inner plastic and applied a little loctite. Yeap... that little piece of plastic became a brittle mess within about 15min of application.
    So.. the lesson here is that Loctite chemically reacts with ABS plastics and causes the ABS to breakdown at a molecular level in a very similar fashion to that of gallium when put in contact with scratched aluminum. Going forward, I'm just going to have to stick with my star lock washers and epoxy it seems...
     
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