Ute

Hi @manterola, AFAIK Video 61 converted many games from xex to rom/car. Not sure if they converted all of them. I have to say that I really like this cart format as it is relatively easy to convert xex to carts. Just a quick example: I found a version of Breakout by a Peter Falton(Hope he doesn't mind) - I used this one for it's simplicity, and loaded it in Dis6502: Two segments should be relatively easy, if there are more segments will add a little complexity but shouldn't be too bad. Next disassembled a few Williams carts to get a feel for the cart headers and it is mostly the same code - just the load to/from addresses change. Looking at the header/trailer, it usually points to this address in the first bank($A032) And here is that section It copies the top area(Circled in red to low memory $600) and then has another copy routine that copies everything from the cart to memory. The first red section: First byte($01) means copy from bank 1, from the rom memory at $A000 to the ram memory at $3800, it uses $C000 to know its done with that section. The second red section: First byte($02) means copy from bank 2, from the rom memory at $A000 to the ram memory at $5800, etc. The final red section is the same but the $FF after $C000 tells the algorithm its done. The sections circled in green set the DOSINI and DOSVEC to $3800. It turns off the cart and starts running. Using a hex editor we can copy everything to it's relevant location. Finally convert the .rom to a .car and it's done. Break-Out.xexBreak-Out.romBreak-Out.car The Wiliiams copy routine isn't super efficient as it is turning the cartridge off and on many, many times while it is copying(Possibly tens of thousands if it's a big file). This could be altered so that it only turns itself off while copying underneath the cart itself($A000 - $BFFF), but I don't know how much time that would actually save.

Yes it's interesting that one half of the 139 isn't used and is hooked up to /S4. I made a replica card just for fun and to make sure the 139 wasn't really hooked up to anything. It's made exactly as the schematic suggested and works for both the single 32K rom and double rom also.

Sorry, I don't know.

I acquired two Williams carts so I was able to reverse the schematic from the cart. But they're different than I expected, they use two 27c256 Eproms instead of one 27c512: As you can see the front of the card is a mess of wires and the back has 5 chips instead of what I was assuming would be 3. So I burned Archon 2(64K) on two eproms(32K each) a low half and high half, and it worked no problem. Next I burned Blue Max 2001 on a single 32K rom and put it on the left side and it ran no problem also. The specs say that a 16K Williams roms exist but I couldn't find any to test. Then I just attached the nice breakout boards @Dropcheck made available for free(Thanks!) and started testing each individual pin: The additional components are a 6K8 Resistor, .1uf Cap, and a much smaller cap that I couldn't make out a value for except that it is rated for 10V and polarized, the actual value was painted over - on both carts. If you're interested I could send you one of the carts(No charge) and you could verify my results. Never hurts to have more than one set of eyes. If not maybe someone else is interested in helping document the schematic? Anyways I got the single chip version up and running: I did make a tiny mistake - I forgot to put on a jumper for 32K compatibility.

Hi @manterola I'm curios as to what your final schematic looks like if you don't mind sharing. I went with this design: It's based on the original Williams Cart schematic:

That helps, thanks @phaeron.

Does anybody else have any thoughts on this? @phaeron @ascrnet

Here is a screen shot while debugging Archon 2 This bit of code is particularly interesting - First setting bank 5 active(STA $D505), then loading a byte from ROM, then switches the cart off(STA $D508), then stores the value in RAM underneath the ROM. The game basically copies all of what is contained in the ROM to RAM. This looks to be the same for Arkanoid and Alley Cat. Looking at a few other carts the loader seems to be the same standard code, just the number of bytes to load and addresses to load them to changes. Can you help me understand why we need to be concerned about the high bits? (A4-A7) It seem like if someone accidentally did something like STA $D5F3, couldn't the high bits just be ignored since in this case they're meaningless? Also the same for STA $D5F8?

Hi, thanks for your feedback. Well, I'm confused on how this works. I've programmed XE Carts, and changing banks is done like this: lda #$06 ;Bank 6 sta $D500 ;Set it as current bank And then access that bank as normal. I incorrectly assumed that the data lines were bi-directional(I thought I read it in the Altirra Hardware Manual) and that while CCTL was low it was getting the Flip-Flop/Latch data from the data lines. Could you explain what is actually happening, because it doesn't make sense to me that it could set the latch any other way. Ok, that makes sense I guess since CCTL and S5(or S4) are probably not driven low at the same time then that is where the latch data should be coming from. Correct AFAIK. The outputs are doing that currently, as well I think RD5 is doing something similar to BasicXE. In my schematic RD5 should always be high until latch 4 becomes high then the signal will be inverted and RD5 will go low and(hopefully) turn off the cart. I'm not too keen on the BasicXE design, it's the OSS 16K cart that is divided in to 4 - 4K banks, one is fixed and the other 3 selected by A0 and A3. But the banking scheme is really odd - "The cartridge occupies 8 KB of address space between $A000 and $BFFF. Its memory is divided into 4 banks, 4 KB each. Bank number 0 (the first one) is always mapped to $B000-$BFFF. Bank in $A000-$AFFF is selected by an access to $D500-$D5FF." I'll keep trying, thanks for your help.

Hi @manterola, thanks for your feedback I realized what I had posted above would not work once I disassembled the Archon 2 Williams cart. I drew this up in KiCad and it should be closer to what is needed: This is sort of a combination of the XE Super Cart and the schematic above. What are your thoughts?

Thanks @Sikor, these are excellent! Unfortunately it didn't contain the Williams cart type. Now I am wondering if this type is exclusive to Video 61 and possibly created later, maybe after Jerzy had created all of those nice schematics. But after disassembling Archon 2, I realized the above schematic will not work for the pcb. Possibly only a minor alteration I believe, which could be either in software or hardware. Anyways I'll keep at it and update this thread if I find anything.

I've been burning a lot of XEGS carts lately, but I would also like to be able to burn the Williams games as well. I've searched on Atari Age and the internet but it doesn't seem like anyone ever made pcb's for these. I did find a schematic, I don't remember who made it, Nir Dary or someone else: But it looks like it matches electrically, the description of a switchable Williams Cart(Except this can do 128K, 16 banks instead of 8 ) "Cartridge takes 8KB memory window, and could be turned off by writing to $D5xx, where X has bit 3 on ($D508, as an example). Three lower bits of address select the bank. Number of banks varies, 8 in type 8, 4 in type 22 and 2 in type 76. On the bootup bank 0 is mapped in." Can anyone give me insight or confirm if this would work? I've got it going in KiCad and ready to get some made, but I would like some confirmation before I go wasting money on PCB's.

Hi, Sorry for the confusion. I did indeed build two cables, but I sold them with a 520 that I had. So I was going by memory since I no longer have them. Did you get it working?

Hi, I think it's the Ribbon1.tiff that shows what pin to connect the round cable to. In other words the numbers written in pencil, are the pin numbers for the round connector if I remember correctly. Honestly though it's a lot of work. If you can afford it I would probably just buy one of these: https://www.ebay.com/itm/334756348147?itmmeta=01HQBZZY0XF0EXPD1S2N1XS6W8&hash=item4df10880f3:g:WakAAOSwDIdj804R&itmprp=enc%3AAQAIAAAA8ONSNaLdFm6mH5b7STOBwN7Lkq%2F7OxZvQiccWSw1Vp24KgzBzPVS7AhgZ%2B8z97SQ4D0eCbMZZAUIaTpaO9dBhGS0AKYlB%2Ft403vUogT%2FKnHEO7niq0xrBjbF9hMuplGK70vVMHQgJT%2F%2BmrOMt8cSVwFOBa44z7IFWuBCrytBPxgxfxOzt0b7%2FPuoHmkpC%2Flq8txwllzPHTVCJLR3RuKn1FH0FP6XknIHciylD8M2kjTq0azlNUHHbam%2Bn4Hqza0PZGBpcyKLBGFhhlHn1hDNMx85QfbgTRS819v5%2FBK0srWup1eyKu3nUpYoMEf7OnZBTQ%3D%3D|tkp%3ABk9SR9Dg__-6Yw https://www.ebay.com/itm/116070881042?itmmeta=01HQBZZY0TSZ26PXB2J1PPXVJ5&hash=item1b065d1712:g:oSQAAOSwInxfNphw&itmprp=enc%3AAQAIAAAA4E5HJcN7j%2Bw0CkgBt0EcSLpQPbnyCWBu6TpGi%2B4jMXWfxo4jqjD9sP%2B9WwnOSPSpQvQ6J4GgChQz7b7bLaoWLtBpLiMMUdC3T5AZswzaQB5U1CyC0P%2B2Z6KsIHyd7jlYWf9czBLccMafqiYLak42HssgqFBbTg0mdfKzcn9WgHh8sU2dAyXEInJO58Bhgd4cEn6xhTTunVesMWjE21H1sg86v3Zvvm3u6I0qmSclnjAsq7cdH7Txks93XGzR3XorJxS5HhMq%2BJzEGiEdNbPsBERwPvUicQD9gmsdxzBUERyg|tkp%3ABFBMxOD__7pj https://www.ebay.com/itm/196119857154?itmmeta=01HQBZZY0TSYE30B2PZ2NFBRD6&hash=item2da9a78802:g:Hn8AAOSwqw5lcPmh&itmprp=enc%3AAQAIAAAA4IrCotcAtfGRkgUe%2BbQzx8lKkPImXjxJH%2BaBpRZ%2FB8KvZma1no3tNNW2vzxe%2Bi5Uyas5t%2BFQsS4vKtTXqmjlSxSUG4sqqsM%2F993RQ2Q5CGG3VQUfNyyDGOICGJeC%2FdhMRnUWfUaha%2FNxmubuW672JYH5mPurRw%2FrBgFCNWPUUHNRzfQPDIiukUa%2BdfbMuuQmFi4dx%2FoiksdhAwb0lvCRqnQ%2B2qmS1OQBBeJvMyE4Ni5KSwLCNdL3SaR%2FOeAlyw%2FN7PU3yhBvpmBvCsJs0gQr5l2JR16PuhYkFn3Z4O41CNQk|tkp%3ABFBMxOD__7pj Good luck! 😉

For anyone else who is interested in these I found the XE Super Cart project on PCBWay: https://www.pcbway.com/project/shareproject/Atari_XE_1MB_XE_SuperCart.html