manterola

I have not checked the expansion yet. But it came with a piece of Velcro to keep it in place. It also came with the original power supply. I opened the computer and found that the pigtail with RCA is a composite output which works great (it is connected to one pin of the main IC). So I am pretty happy with it.

Not an Atari, but still proud about it, and for 5 euros... First time typing in a computer, it was in one just like this little Sinclair (minus de RAM expansion).

Sorry, I have been out of town. I will find out the values you asked me and let you know.

I have some question about Williams cartridges. Who put together the Williams ROMs circulating around the interpipes? , where did they come from? Are they dumps from commercially available cartridges? It looks like someone adapted disk version games to cartridges given the titles I was able to find: Archon2, Alley Cat, Zybex, Colossus Chess. In other matters, I received my first batch of PCBs and I discover why the original design of Bill Williams includes a RC pair connected to the flip flop reset: it is needed during power up to delay the reset pulse and my guess this is needed to start the cartridge at a known state. I added the RC pair, but I used other values since I only had 0.1uF capacitors available but I kept the RC about the same: so I used a 10k resistor. I tested my PCBs with that mod and it worked. Therefore, beside other minor modifications, I have sent the updated PCB design to fabrication, and I will be able to test those PBCs in about 10 days. If someone is interested in having some of the revised PCBs or some of the ones not working out of box, but easy to modify, to create your own Williams cartridge, please contact me. I am sure almost everyone has a spare Pacman or Star Raiders cartridge to repurpose.

I'm going to miss this one. I'm on a trip with no access to Atari 8 bit greatness

Similar Retrotink clone you can find everywhere (Aliexpress, Ebay) is the retroscaler2x. Another option is to find a 4:3 LCD TV (with S-video) for cheap in a thrift store: you shouldn't pay more than $15 or maybe $20. Of course, the bad quality conversion and/or artifacts could still be present as it varies from TV to TV and from Brand to Brand, but when I see one for $10 or so, I try my luck.

Yes I am. For what you posted in the schematics we were pretty close: that clock signal going to flip flop is the same, and the signal going back to Rd 5 is the same. The Williams cart uses a ls175, which I mentioned before, but I used an ls174. I also miss adding a jumper to allow the use 32k eproms, but it is really not that important. Once I get my PCBs I can send you a cartridge for your to p lay and explore. Edit: as @phaeron pointed out, the main difference is that S5 and S4 are connected to the unused half of the ls139. Probably that hidden banking scheme was never fully implemented, and/or never documented, which it is pretty awesome we are discovering that today.

So did you get the original Williams Cart schematic!?!? I used the one posted on March 10th.

I am sending this PCB for fabrication. Then I will see whether it works or not. If it is working I will share the gerbers if someone is interested.

4 years ago or so I got belts from audio lab of Atlanta Georgia. Audiolabga.com for my hong kong made 1010. I have not checked, but if you have the measurements, they might have some of the belts you are looking for.

The best I could in level 9:

FYI. This is how it is done in A8PicoCart. else if (!(pins & CCTL_GPIO_MASK)) { // CCTL low addr = pins & ADDR_GPIO_MASK; if ((addr & 0xF0) == 0) { bank = addr & 0x07; if (addr & 0x08) { RD5_LOW; rd5_high = false; } else { RD5_HIGH; rd5_high = true; } } } So, A8Pico actually decode A7-A4 (checks if (addr & 0xf0) is zero i.e. if A7-A4 are all zeros) then it looks the A2-A0 bits for the banks (addr&0x07) , and finally the A4 bit (addr&0x08) to en/dis the cart with RD5.

Regarding belts for all tape recorders and for the 1050 hong kong you can always try your luck in AliExpress while waiting for console 5.

I would like to have at least one Atari 8bit with the stereo implementation, but I already got one POKEY from Brad. It is only ONE per person (for life). I got mine like 5 years ago, and he did not want to sell me another one. I also need to fix a 600XL half failing POKEY (keep repeating key presses, but probably good for stereo). Anyway, what I am trying to say is that there are valid reasons to get more than one POKEY. I have been waiting for a Ballblazer cartridge for 1.5 years. I have notification in all the typical online sites and apps, still nothing reasonable (I guess Saturday, there were a guy selling the cartridge at $35 plus $7.99 shipping, which is the first time I encounter that, and it actually matches the price range you mentioned). I also got a bit concerned of destroying a cool and a bit hard to find cartridge to use the POKEY inside. So now I am just seriously considering using one of my computer to supply spare parts (cannibalize it), for example using an 800XL or 600XL for the Delay line, the Pokey, the keyboard MB connector, the plastic piece over the cartridge, etc. In summary, I really think there is a market for the perfect implementation of POKEY without extras using the cheapest FPGA possible.

Okay, so I modified (simplify) the schematics using Avery's ideas. My main concern is the clk input to the F/F, since sometimes is used inverted, but I read the LS174, LS74 and LS175 datasheets and they are all positive-edge triggered and basically interchangeable for this purpose. So, I think this should be the correct way, but it might work with a logical inverter (logical negation) in front of it. The 174 has more input/outputs, but the 175 is nice since it includes the inverted output as well (Q and /Q). Anyway, I am willing to give it a try, unless there are more suggestions about it. BTW, there still is an unused NOR gate to use it as inverter if needed, but it is not in my original screenshot, so I draw it, to bring attention to that open issue.