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alex_79

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Status Replies posted by alex_79

  1. Jess Ragan

    Uh, guys? Any of you know what EPROMs are in this Telegames lot? https://shopgoodwill.com/item/175842686

    1. alex_79

      alex_79

      Bootleg copies of common 2k and 4k games.

  2. bent_pin

    Anyone got a cheaper way to burn up 7 clocks on the 2600? 

    dey
iny
sbc #0

    4 bytes of ROM and 7 clocks.

    1. alex_79

      alex_79

      Yes.

    2. (See 2 other replies to this status update)

  3. bent_pin

    Anyone got a cheaper way to burn up 7 clocks on the 2600? 

    dey
iny
sbc #0

    4 bytes of ROM and 7 clocks.

    1. alex_79

      alex_79

      "sbc #0" will alter the accumulator unless the carry is set., and it takes 2 cycles, so that code takes 6 clocks in total.

       

      Typically you do 

      nop
nop
bit 0

      But the bit instruction alters the flags. You can avoid that by using the undocumented "nop ZP" instruction: 

      nop
nop
nop 0

      takes 7 cycles and doesn't alter any register or flag.

      It's what the "SLEEP" macro in "macro.h" does if you use 

      SLEEP 7

       

    2. (See 2 other replies to this status update)

  4. bent_pin

    Is Gorf available as a ROM from the author?

    1. alex_79

      alex_79

      Yes.

      Google "Champ Games".

    2. (See 2 other replies to this status update)

  5. Corby

    Ok wait! What? It has wi fi????

     

    https://www.ebay.ca/itm/165966176177

    1. alex_79

      alex_79

      The Pluscart has been around for a while:

      https://pluscart.firmaplus.de/pico/

       

      There are a couple of active threads in the 2600 forum:

       

      And a dedicated club:

       

    2. (See 1 other reply to this status update)

  6. jwelsh

    Ok, I've been looking into this for a while and have found no info. What's the deal with the 1st release of Pesco and ebivision pac man? This is a screenshot from YouTube, but this happens on my actual system in both games 4 out of 5 times I switch on the power. I assume this is a programming bug and not system related, but I honestly have no idea. Pesco and pac man are missing half their bodies and seem stuck in the walls, along with the enemies.

    Screenshot_20220615-135726_YouTube.jpg

    1. alex_79

      alex_79

      It's a bug in the game: it doesn't correctly initialize the CPU. In particular, the decimal flag is not cleared, and the game glitches if the flag happens to be set when powering on the console. (the state of cpu registers and flags is undetermined at startup and should always be initialized)

       

    2. (See 1 other reply to this status update)

  7. TwentySixHundred

    Does anyone know what CPU the Voyager space probes used? Im assuming the 6502 however cannot find any information about it.

    1. alex_79

      alex_79

      The computers in the Voyager probes are custom built.

       

      https://voyager.jpl.nasa.gov/frequently-asked-questions/

      https://history.nasa.gov/computers/Ch6-2.html

    2. (See 2 other replies to this status update)

  8. Max_Chatsworth

     Why does the edit profile have a field 'About Me' that doesn't actually show up when viewing someone's profile?

     

    1. alex_79

      alex_79

      Weird. It should show up in one of the tabs, next to "Activity" and "Clubs"

      417874327_Screenshot_2021-05-11Max_Chatsworth-AtariAgeForums.thumb.png.800200d5b29914a44697e34473a0c9fd.png

       

      Are you browsing on a Tablet/Phone?

      Maybe it's different on mobile than on desktop PCs

    2. (See 3 other replies to this status update)

  9. Max_Chatsworth

     Why does the edit profile have a field 'About Me' that doesn't actually show up when viewing someone's profile?

     

    1. alex_79

      alex_79

      It does show up only if the user actually put some info in it. I can see the "About Me" tab in your profile.

    2. (See 3 other replies to this status update)

  10. carlsson

    I suddenly felt old. In a quiz for fifth graders (11 years old), one of the questions was which invention came up with the keyboard, long before computers.

    I.e. a typewriter, which supposedly would be something ancient for people in the 21th century.

    1. alex_79

      alex_79

      I still have a couple perfectly working Olivetti typewriters: a "Studio 46" which was the one I had as a kid and the "Lettera 32" which belonged to my grandfather.

      I still use them from time to time e.g. for labels.

    2. (See 14 other replies to this status update)

  11. IntelliMission

    Dear youtubers: Please upload your longplays of 80s and 90s games at the right aspect ratio and stop deforming these masterpieces. Thanks in advance, IntelliVision

    1. alex_79

      alex_79

      thumbsup.png.ff36625c942f394bf7949a7ae0e9fa25.png

    2. (See 5 other replies to this status update)

  12. ApolloBoy

    I'm in the midst of converting a Fatal Run cart into the NTSC version and for some reason it's not booting. Any ideas?

    1. alex_79

      alex_79

      Yes, that board doesn't need extra logic, and in theory it should work just by replacing the rom with a pin compatible eprom. Sorry for the confusion.

    2. (See 18 other replies to this status update)

  13. ApolloBoy

    I'm in the midst of converting a Fatal Run cart into the NTSC version and for some reason it's not booting. Any ideas?

    1. alex_79

      alex_79

      Sorry, we posted at the same time. In many 2600 carts, the mask rom integrates the bankswitching logic. So you can't just replace it with a standard eprom, but you need to add the bankswitching logic as an external circuit. The PAL Fatal Run cart you have might be different. How many chips does it have on it?

    2. (See 18 other replies to this status update)

  14. ApolloBoy

    I'm in the midst of converting a Fatal Run cart into the NTSC version and for some reason it's not booting. Any ideas?

    1. alex_79

      alex_79

      After re-reading the previous posts, I guess the original cart uses a standard otp eprom, so the bankswitching is already implemented in the board. In that case, disregard my previous reply...

    2. (See 18 other replies to this status update)

  15. ApolloBoy

    I'm in the midst of converting a Fatal Run cart into the NTSC version and for some reason it's not booting. Any ideas?

    1. alex_79

      alex_79

      Also double check your bankswitching logic, whether you're using a PLD or off-the shelf logic ICs.

    2. (See 18 other replies to this status update)

  16. bluejay

    www.commodoreage.com leads to AtariAge! (Found while searching for www.*videogame company*.com)

    1. alex_79

      alex_79

      And so does www.colecoage.com and www.intellivisionage.com...

    2. (See 2 other replies to this status update)

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