Atari 5200 BackBit PRO 4-port Soft Reset notes and modification
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!
Ivory Tower Collections
There are no comments to display.