Saturday, 2 February 2019

Reply to Cole Johnson

Hi Cole,

Thanks! I heard about your work on a MAME forum on bannister as "seanriddle" posted about you
and the great work your doing for the AY-3-8500-1. I cannot imagine the idea of trying to retrace the
die inside the chip as i've read about the creator of the AY-3-8500 (Gilbert Duncan Harrower) that it took about a 1,000 transistors to make the circuit of this chip. For anyone who wants to read the interview of Mr.Harrower done by Nate Lockhart (a few days ago), go here:

https://thegeekiverse.com/interview-with-gilbert-duncan-harrower-inventor-of-the-pong-on-a-chip/

And i've noyiced that you responded to Nate's interview and writing that the AY-3-8500-1 has
2,318 transistors ?!?! WOAH!! And if this can help, have you read this post: http://discreteconsoles.blogspot.com/2015/10/emulation-of-ay-3-8500-1-and-clones-soon.html

There's a Pong console that is totally made with TTL's (don't know how many) called the "Palestra-2" made in the Soviet Union. In the post, there is a link to download the schematic of this console.

And if anyone from the MAME/MESS team (especially seanriddle) needs the schematic of the uPD777C (Epoch Cassette Vision dedicated chips), i was able to get my hands on it thanks to the developer of  those chips.

And for fun, i've made a Pong clock simulator of the AY-3-8500-1 in 2013 here: https://love2d.org/forums/viewtopic.php?f=5&t=76068&p=156817&hilit=8500#p156817

So keep up the great work you are doing Cole, one day when we will be able to play the games from the AY-3-8500-1 in emulator form, it will be because of the hard work you've accomplished!

P.S., my cat says "meow"! :p (lol!)

1 comment:

  1. The highlighted images used to generate the netlist are here (https://gitlab.com/TheProgrammerIncarnate/chip-processing/tree/master/GIgames/ay38500) in case you're interesting in how the process works. And if you think highlighting a 2K transistor chip is hard, JohnPCAE highlighted the SP0256 voice chip, which comes in at 13521 transistors!

    I'm planning on emulating other discrete game chips once the AY-3-8500 emulation is complete. Doing this requires external connection diagrams along with internal schematics, which can generated from decapped + annotated chips or acquired from the manufacturer or developer. The AY-3-8500 is extremely well documented, other chips are not however which means information you come across may be very helpful in the future.

    Emulation preserves gameplay but not hardware, so thanks for your work on photographing these systems. (Although I worry about what effects prolonged exposure to 1970s consumer design will have on my health)

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