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manterola

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  1. 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.
  2. 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.
  3. 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.
  4. 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.
  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.
  6. 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.
  7. Yes, I really like @phaeron comments. It give a lot of good tips. It also provides information about how this is implemented in Altirra and that something what I did not think before. Which is super important since allow us to try the ROMs you have and even try changing the sta $d506 for a $d5f6 for example and see how it should continue working. I would like to know how a8picocart and avgcart implement this Williams banking scheme. Maybe @electrotrains and @tmp can shed some light. For example, my assumption that properly decoding the upper address lines is good to make it satisfy the description of how Williams banking works, but in practice it should work without it but might produce conflicts with other hardware. So it is basically a typical trade off. Same with RW, you can do an LDA from $D506 and it will switch banks, if you don't take RW into account, that would be okay, and depends on what the actual code of the game does. I will modify the circuit to get rid of the LS00 and make it work with the F/F and the NOR gates, if possible.
  8. This is my best score so far. And my best score in level 9:
  9. I put together this, but there are many uncertain things, yet. Some variations w.r.t. the XE cart and the OSS regarding disabling the cart, etc. But this is the basic idea. As I mentioned before, I think A4-A7 addresses should be decoded to detect and disable latching the flip-flops if there anything different from zeros. But I need more time to think that part, or help in using some "black magic" to get rid of the gates and instead use 138, 153, etc. (high order glue logic) to do a better address decoding. To use this with your example (activate bank #6 counting from zero) you just need to do: STA $D506, no matter which number is currently in the Accumulator. Could you confirm that the ROM for Williams banking does this kind of stuff? I guess you mentioned Archon 2 uses Williams banking scheme.
  10. That schematics uses the 0s and 1s in the data lines to select the banks. Which makes sense in XE cartridges. But according to the description in a couple of sites, Williams banking scheme depends on the address lines: "An access to $D500 selects bank 0, $D501 - bank 1, etc. An access to $D508-$D50F disables the cartridge" Therefore, first change is to feed the 74174 with the A3, A2, A1 and A0 instead of the data lines. Another thing I noticed is that Williams Carts are 8x8kb=64kb max, please confirm that. A2, A1 and A0 flip flop outputs should go EPROM A15, A14 and A13 respectively. A3 should drive the logic to deactivate the cart (i.e. RD5 signal back to the Atari and OE, CE, to the EPROM, see BasicXE cart posted by Sikor for an idea on how to do that). Now, to ensure that the processor is accessing $D50X (and nor $D512 for example), and follow the description quoted above, A7 to A4 might go all together with the logic that activates and latch the flip-flops (however, I have no idea if this is really implemented in an original William cart). I am not so sure about it, it might work without that part. Something like this or similar: _______ O2 -----o| | /CCTL----| BIG | A7-------| NOR | A6-------| GATE | A5-------| |o--------> CLK A4-------|_______| Another thing I would copy from BasicXE cart schematic is the generation of the CLK signal. In your schem. is inverted wrt the BasicXE cart. Since BasicXE cart looks to me closer to the Williams cart design, I will copy that part (probably has something to do with timing differences b/w data lines and address lines). I have no way to now if this will ever work, but I will be glad to give it a try, someday, with a game ROM known to work under the Williams 64KB banking scheme.
  11. I can make it work (sometimes) by booting the 800 computer pressing Start, so it beeps and gets ready for cassette loading, then press reset and that should get you to the A8Pico menu. The problem is that the system stops working (sometimes again) when navigating the file system of the sd card. If I get to the point where I select the desired ROM or CAR to emulate, the selected cart starts and everything is fine. Otherwise, I boot the 800 and try again. The same happened to me the couple of times I tried the A8Pico cart in a stock Atari 400 with OS-B: it got stuck, sometimes, while browsing the sd cart content. I don't know the reason of this problem, but I suspect it has something to do with the memory area used for the RP A8Pico cart <---> Atari native menu program communication since once you start the emulation of a selected ROM everything works as expected and the system is rock solid.
  12. Hi @Ute, the schematics you posted does not look it is going to decode the specific addresses mentioned in the description: "turned off by writing to $D5xx, where X has bit 3 on ($D508, as an example). Three lower bits of address select the bank". In order to implement that you can use some logic gates, a good example is shown in the basicxe cartridge (also in other carts schematics), which looks to me (after a very fast check) very similar to the schematics you posted. I would like to check this out tomorrow, with more time.
  13. Another distinct feature of this type 4 variant is the weirdness of the "/" . I got a 600xl with that keyboard, here some pictures:
  14. I don't know if you noticed, but the button is just the center, the frame of the button is just molded together with the case. And I just discovered that there is some kind of "spring" for feedback, if we can call it that way... it is just a small and fragile piece of plastic. At least I have the possibility of upgrade the buttons with some real springs.
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