Mike's PCjr Page

Thanks. I'll give it a try. I do have the J8,J10 and J12 set although I did also try J8, J5 and J12.

I had tried CS2, CS3, CS4 and CS5 with the file that I removed the PCJRCART header and none of the CS selects worked. but I just ried your file with CS2 and it works fine now. Obviously I had soemthing wrong with my modified file. I used the EPROM programmer buffer commands and edited the file to remove everything up to 55 AA and then programmed. Did I miss something?

I found the problem with my files. I downloaded a HEX editor program and did a compare with your file and mine. There were two bytes different. Either I cut the file too short or the EPROM buffer somehow truncated the file when I edited it. The last two bytes in the file (12 C8) were changed to 00 00. I corrected the two bytes and burned another EPROM and it worked fine as well.

Thanks for the help.

Glad to hear it worked out for you!

I made another to factory specs and now have two! As you see in the picture, my wife got creative with the second label on the white 3D printed shell

The DA00.bin file is the Jrvideo enhancements and the DE00.bin is the keyboard routines. Not sure how the combo cartridge sets up all three but I decided to esperiment. I first tried the DA00.bin on separate EPROM after removing the header and it worked fine. I then tried the DE00.BIN but no luck however I think it may be because I have the TEXELEC keyboard dongle that works with a standard PS2 keyboard. I'll revisit this later and try with the regular Jr keyboard in place. Next I copied the DA00.BIN file (Video) and tacked it onto the end of the D800.BIN file(Compatibility file) and burned that to an EPROM and it worked, loading both the compatibility fixes as well as the video enhancements. I then tried adding the keyboard file to the end of the other two but it again just hung the system but still didn't try with a stock keyboard.

Just for reference, I think the C000.BIN file is the JRIDE BIOS and the C800.BIN is a Racore expansion BIOS.

I came to the same conclusions on the other files... Hmm now I'm thinking my next project is to build a Combo Cart 3.

Just combined all three files, burned to an EPROM and tried with the stock Jr keyboard and it works fine.

That's great! Can you post the combined files image? Thanks

Ok I was able to combine the files to one ROM image and it works! I tried the files in different orders and it seem to work about the same no matter which order the files are arranged.

Some differences I noticed from my Combo Cart 2 is that the Combo Cart 3 does not have the Quicksilver (fast boot) added to it?? and the jrVideo splash screen doesn't have the moving color graphics??

Sorry, I didn't see this until after your second post or I would have posted the combined file for you. I'm relatively new to the PCjr so I am not familiar with Quicksilver or the moving graphics of the jrVideo that you mentioned. I have a ROM file of the Quicksilver cartridge but it looks to be a bit different. I think it is a BIOS replacement and needs to load at F000. I'll have to find time to try that one sometime. Here is the file if you want to try it.