Jr Cartridge blank for eprom

[Corey986]

Has anyone done a layout for one of these or does someone have a source for one?

If you have a layout, I'm willing to order a bunch from a PCB mfr and see about 3D printing up cartridge cases.

Thanks,
Corey

[Brutman]

I thought that Alan had done blanks recently. If not, I have some of the old ones from Integrity Technologies, including the shells. There is not much on them. (I have to dig it out - I'm kind of jumbled since I moved recently and am planning to move again.)

And yes, a 3d printer is perfect for this project. I live near Gene B. and he has quite a bit of experience and a few printers to choose from; bringing him a cartridge shell has been on the to-do list for a while.

[alanh]

https://www.retrotronics.org/svn/jride/trunk/supercart/

I did a super-cartridge a long time ago. It has a 512K flash chip and supports selecting any 32K or 64K memory range of the flash device to respond to either cartridge window's upper and lower chip select lines. You can also have it respond to the system bios chip select and it will map the lower 64K to F0000. The PCB dimensions are pretty accurate.

[Corey986]

Mike,

When you say you don't have much on the integrity cartridges, you mean documentation? Do you recall if the PCBs are self documented in that the jumpers are labeled clearly. I might be interested in a couple of those since they are already make otherwise I'll use Alan's PCB layout and have a couple made.

Thanks,
Corey

[Shaos]

I'm pretty close to replication of the cartridge board - anybody interested?...



P.S. Yes, I killed real cartridge to reverse-engineer it (and use it as test-bed for my own EPROM), but I preserved old ROMs (it was "IBM PCjr ColorPaint" when it was alive):

[Meknapp]

Yes, I'm very interested in this project!!

[Trixter]

I'm interested, but I don't know when or where I would be able to get to a project that uses it. Too many projects, too little free time. If you're making a large run, I could certainly chip in for a few.

I'm one of the people who created 8088 MPH. For our next demo, we considered making a 100% stock 128K PCjr demo, and the only way to do this is to shoehorn it into one or two cartridges (so that the program code isn't running in the slower 128K RAM).

[alanh]

Would it be considered cheating if you had a SD card on the cart and you paged content in/out of a frame window in the D/E segments by a specific address read sequence detected by an FPGA?

[Shaos]

512K parallel ROM with programmatical paging may be? It should be relatively easy to design (I want to do that sooner or later)

[Trixter]

Would it be considered cheating if you had a SD card on the cart and you paged content in/out of a frame window in the D/E segments by a specific address read sequence detected by an FPGA?

Yes! In the world I occasionally compete in, you must limit yourself to tech that was period-appropriate. Going outside of period-appropriate lands you in a different category altogether ("wild") as it crosses over from being a demo to being a homebrew showcase. Going even further outside of period-appropriate (such as a 1G SD card full of program code) usually gets you disqualified ;-)

While burning your own 64K rom onto two carts was not typical, it was indeed possible so it would be allowed. But the point is moot, since we abandoned the idea because we wanted more than 128K of code. And then we abandoned the idea of a PCjr demo because we still have some blood to squeeze from the 8088+CGA stone.