What's new
Well, the future are larger capacity Flash ROMs, though that'll require 3.3V to 5V bus translation and a programming infrastructure, which would be as much work as the MVS/AES multi carts. Until there is a good solution for implementing the ASIC that'll be difficult to achieve. (Unless someone wants to license an ARM soft-core...)
 
The seller I buy from delivers everything in tubes at least.

The last batch several weren't blank and it took a lot of attempts at erasing to get them to erase, and 1 was bad.

It's only going to get more difficult unfortunately. They're not making new EPROMs so the quality of recycled chips will go down
As someone who's ignorant to how eeproms are made, why is it not possible to reproduce these today? Is it just the market not strong enough to warrant any new production runs? Are they that complex where they cannot be reverse engineered?
 
EEPROMs (Electronically Erasable Programmable ROMs) still absolutely exist and are manufactured today.

EPROMs (ceramic chips with the UV erase window) have long since been replaced by those.

There's no reason to continue making UV erase EPROMs anymore because EEPROMs are cheaper to make, smaller and fit on modern boards where space is at a premium.

It's possible to make adapter boards, so I assume that will be the future.
 
I have ddp3 and ketsui carts made currently however I am noticing a graphical issue on the ketsui cart. On the title screen a tiny portion of it jumps up and down however the game is fully functional. Figured it was just a fluke I started playing a credit and noticed that there were models in the background bouncing around like crazy like on the title screen so I assume something is busted.

Swapping the char board with ddp3 while the title screen is a garbled mess I don't see anything jumping up and down so I assume it's the char board. Checked for bridges and triple-checked my soldering and it looks fine. Any idea where I should be focusing my efforts?

UatsC5Nl.jpg
 
I had a similar issue, it was my p1 the chip was faulty.

It read, wrote and erased fine though.
Seems to happen pretty often with me though lol.
 
Maybe one of the B-ROMs is dodgy? Graphics data are stored compressed, B-ROMs contain the mask and A-ROMs contain the actual pixel, so if the B-ROM doesn't produce the right data at the right time it would shift the sprite image.
 
I had figured (and hoped) it wouldn't be the eproms but it's all confirmed at this point. Shortly after making that post DDP3 stopped working entirely. While making these I had purchased a top3000 which ended up almost catching fire and being tossed :(

So I'd love for some suggestions on a decent programmer that won't a) burn my house down and b) not destroy my wallet that can do a 27c322. At this point I just want to redo all the eproms because I don't trust them.
 
I always recommend the Wellon VP-598 . It costs a little more upfront than a Top 3000 but it handles everything I throw at it and it has good software.

The Flashcat USB costs less upfront and can do 27C322 with the right adapter, but the software is flaky in my experience.
 
I always recommend the Wellon VP-598 . It costs a little more upfront than a Top 3000 but it handles everything I throw at it and it has good software.

The Flashcat USB costs less upfront and can do 27C322 with the right adapter, but the software is flaky in my experience.
That Wellon was precisely the one I had my eyes on! Are they reliable from aliexpress or is it one of those devices you should purchase from a licensed distributor due to clones?
 
I'd be inclined to purchase from a licensed distributor. Don't buy an expensive programmer from AliExpress. :)
 
Well, I've done something wrong... No sound, and the game crashes in stage 1.

 
If the game crashes I expect some kind of problem on the prog board with the program eprom or the connector.

For sound the problem can be the sample ROM on the char board, the multiplexers or the address decoder. (Or a connection problem.) Check that you have the multiplexers installed the right way around, and that there are no solder blobs connecting unwanted pins on the address decoder.

PGM single game PCB assembly and troubleshooting
 
sent the full shell design to my university lab for 3d printing, only cost $23 for the og cart style shell.
Pretty great in my book.

If I were to try the other style with the plexi design I'm sure that part would be cheaper, But I don't know the first thing about laser cutting.
Where Would you recommend buying the plexi and what variety is best?
 
sent the full shell design to my university lab for 3d printing, only cost $23 for the og cart style shell.
Pretty great in my book.
That's a pretty great price, but it's also pretty close to what I estimated as being just the material/overhead cost.
 
if you use revision 1 of the char board check that you swapped pin 2 and 3 of U10
This may be an issue. I'll swap them later today and see how it goes.
Fixing this brought back my sound, and now I can get mid-way through Stage 1 before it crashes.

Everything is facing the right direction. And I've scoured both boards for unwanted bridges.
 
Back
Top