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hendersonn

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  • Gender
    Male
  • Location
    Virginia
  • Interests
    I like to study retro computers and things of the like.

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  1. Aw nuts, guess I didn't go back far enough. Thanks a bunch, I think I have what I need now.
  2. Interesting, I must have missed that somewhere. That aside, I can assume the data and address lines are the same?
  3. Is this for the 28C64 or the 2732? I'd like to start by reading the latter on a breadboard via LEDs first. I'm also a little confused as both chips' datasheets refer to the chip select line as being active low; not to mention the absence of an inverter on the original cart.
  4. Hello, As a weekend project I've been trying to get a 28C64 working with on recycled Pac-Man cart board. I'm under the assumption the original PROM used was the 2732 based on a few text documents sprinkled on the web. The idea was to solder some jumpers to the cart's bare PCB, which in tern would be connected to a breadboard. As a test, I reinserted the 2732 onto the breadboard and successfully ran Pac-Man. Next I tried replacing the 2732 with the 28C64 and rewiring as needed to no success. The 28C64 has two copies of Pac-Man written to it, I have confirmed this with several tests: I can play the doubled Pac-Man ROM image in Stella, I have compared both the doubled and the original PROM image in a hex editor, as well manually checking the first few addresses of the 28C64 (by connecting the data bus to LEDs and grounding the appropriate address- comparing the LED output with the hex editor). All this makes the think the 28C64 is working as it should; when I try to manually read the 2732 in a similar fashion, I get no activity on the data bus. I'm curious if this is even a 2732 at all, maybe I have the address lines mixed up. I've confirmed that the (assumed) 2732 isn't fried multiple times as well, just to make sure. I must be missing something silly, hopefully you guys/gals can point me in the right direction. Thanks. tl;dr I'm trying to connect a 28C64 EEPROM to a Pac-Man board with the assumption that Pac-Man uses a 2732 PROM to no avail. ** I've searched the forums and google- but nothing turns up complete solutions.
  5. Hello, I fried my Supercharger for the 2600 (don't ask...) I really liked the device and would like to replace it. I opened it up and it looks like there is pretty much nothing I can do to repair it, so if anyone has one they'd like to let go, let me know.
  6. This is relevant to my interests; Good work!
  7. Could be the TIA, have you tried swapping it yet (assuming you have another on hand)? I'm sure you would've tried that, just thought I'd give some input.
  8. Interesting; I wonder if a similar method could be used for new peripherals. Now that I think of it, I wonder if the CX-3000 utilized matrix decoding as well... Edit: I didn't bother looking into the graduate, I see the motherboard is well populated, so it probably does.
  9. "There's more than one way to skin a cat" as they say; I saw one thread someone made on how they put together some tunes (although I can't for the life of me find it now This), but it was a little confusing to follow. I thought It would be as simple as loading it from a bank (like a bitmap for player graphics) or something along those lines. I quickly realized it wasn't that simple. There doesn't seem to be a whole lot of documentation on this so I figured I'd just ask. My initial thought would be something like this (pseudocode): LDA Frequency1 STA AUDF0 DELAY LDA Frequency2 STA AUDF0 LDA TONE1 STA AUDC0 DELAY LDA Frequency3 STA AUDF0 DELAY Been going round and round with this; wondering how you all got your music going. Thanks for any input. Edit: I'm writing it in assembly; I'm not using bB.
  10. So did I miss something in the Stella Programmer's Guide? Going over the two source codes, I'm curious about something: How do you know which Input Port to check(and when)? From what I can tell, 0,1, and 4 deal with Player0 and 2,3, and 5 deal with Player1, but I'm confused on which order you check them- or if it even matters.
  11. Are there any resources available that explain the input ports a little more, I think that's where I'm getting stuck. Even when porting over the code that reads the ports, it isn't really doing anything- even with Stella set to Keyboard, the only visible effect on screen is from toggling the Joystick's fire button. Give me a second to upload a sample... Just to get a feel of how it works, I'm just trying to manipulate PF1 to show the change, nothing fancy. broken.asm
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