Ray Carlson's website often refers to the Jupiter Lander Cart being a great tool to identify bad Kernel ROMs. So I searched around the internet for two things.
1) Why the cartridge was good for this diagnostic and a good reference came from the C64 Preservation website on the Commodore Max and Ultimax carts.
2) How could I make a cart and have a bit of fun at the same time, ultimately I settled on BWACK's VersaZIF64 github project and the original project Versa64Cart for the documentation pdf.
Building this project gave me another great excuse the burn some more roms using my Xgpro TL866II Plus and play with my eraser from Big Moon (or the scary skin cancer box).
VersaZIF64
I built this project pretty
quickly by uploading the Gerbers to PCBWay and then ordering all of the
BOM items from Digikey. I thought as I was going to get 5 PCB's
anyhow, I might as well build them all.
It was really easy to do everything as it was all documented very nicely in the github repository.
Burning the ROM
In the Versa64Cart git repository there is a great PDF on how to setup your cart after you've built it. It explains how to convert the .crt file to a .bin file for burning, how to get the config from the .crt file and then how to set the switches on your cart to get the rom to run.The ROM itself is a Ceramic DIP 28 with a little window in it so it can be erased using UV light. This particular chip is a 27C64 which holds a whopping 8K ( the smallest single image I can use for C64 carts ). I also have some 27C128's which I can jam 16K images on (or 2 x 8K images).
Diagnostics
So how does this cart compare the my other carts and will it actually be useful. Well it so happens that I have a black screen C64 that generates a PAL signal (not as bad as the last repair I did). So these will be be my new test suite for my next C64 black screen repair.
Ultimate 64 - This works with the c64 only when the menu is entered (otherwise I get a black screen). The keyboard works but games don't load and the drive resets when the C64 resets.
On the last black screen repair a similar result was seen with a good kernel rom and a bad CIA1, but the text was a bit garbled. In this case the text is perfect and the keyboard works fine.
Dead Test Cart - This doesn't work. There is no white flashing so the RAM is possibly good?
Jupiter Lander - This starts up fine then gets some corruption after the title screen
