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Atari 2600 Service Manual [pdf]

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Re: Atari 2600 Service Manual [pdf]

#3
post #2

I used to love playing my family Atari 2600 as a 5 year old kid. Here’s the same Atari, 40 years on (in original condition) being played by my own 4 and 5 year old kids! https://twitter.com/sunpazed/status/1332832920101240833

40 years? How many controllers have you broken/replaced?

Re: Atari 2600 Service Manual [pdf]

#4
The thing I found fascinating about this machine is it has no video RAM at all. I couldn't initially understand how it could possibly work without a frame buffer. What it does is you have to redraw the screen dynamically on every frame with precise timing in sync with the sweep of the CRT beam. It also has little memory generally. There's no dedicated RAM chips, there's 128 bytes (not kilobytes) on the PIA you can use and that's it.

Re: Atari 2600 Service Manual [pdf]

#5
post #2

I used to love playing my family Atari 2600 as a 5 year old kid. Here’s the same Atari, 40 years on (in original condition) being played by my own 4 and 5 year old kids! https://twitter.com/sunpazed/status/1332832920101240833

Great games are still being made for it [0] and there’s an awesome show called ZeroPage Homebrew [1] that streams twice or more a week. They exclusively play homebrews for Atari systems and the developers are often in the chat.

[0] https://atariage.com/store/index.php?l=product_list&c=24

[1] https://atariage.com/forums/topic/276956-zeropage-homebrew-t...

Re: Atari 2600 Service Manual [pdf]

#6
Don't flowcharts suck? They are bad enough when you have Visio or whatever to help you copypaste through the busywork, but in the old days they had to put them together with one of these toys:

https://www.ecosia.org/images?q=plastic%20flowchart%20templa...

I'll tell you how to service an Atari 2600, though. Even in 1982, chuck it in the dumpster and head down to K Mart for a new one. Put that in a flowchart.

Re: Atari 2600 Service Manual [pdf]

#7

Don't flowcharts suck? They are bad enough when you have Visio or whatever to help you copypaste through the busywork, but in the old days they had to put them together with one of these toys: https://www.ecosia.org/images?q=plastic%20flowchart%20templa... I'll tell you how to service an Atari 2600, though. Even in 1982, chuck it in the dumpster and head down to K Mart for a new one. Put that in a flowchart.

Lol a new Atari was $200 in 1982 dollars, so if it could be serviced it'd probably be worth it then. The cheapo $50 ones didn't come out until '86 or '87 I think.

Re: Atari 2600 Service Manual [pdf]

#8

The thing I found fascinating about this machine is it has no video RAM at all. I couldn't initially understand how it could possibly work without a frame buffer. What it does is you have to redraw the screen dynamically on every frame with precise timing in sync with the sweep of the CRT beam. It also has little memory generally. There's no dedicated RAM chips, there's 128 bytes (not kilobytes) on the PIA you can us…

Basically you have some CPU cycles in the "horizontal blank" part of each line that you can use to change chip registers for that line.

The TIA had some delay bits/latches so you could write player 1 data and player 2 data on alternate lines, but with one delayed so they'd appear on the same line.

Your actual game code was expected to run in VBLANK.

You can of course alter registers while the line is being drawn, if your timing is precise and your data is prepared, and that's the basis of doing advanced things like 6 digit scores and non-symmetrical playfields.

Re: Atari 2600 Service Manual [pdf]

#10

The thing I found fascinating about this machine is it has no video RAM at all. I couldn't initially understand how it could possibly work without a frame buffer. What it does is you have to redraw the screen dynamically on every frame with precise timing in sync with the sweep of the CRT beam. It also has little memory generally. There's no dedicated RAM chips, there's 128 bytes (not kilobytes) on the PIA you can us…

There were other computers from that era that did the same thing but the 2600 did it more elegantly:

https://www.timexsinclair.com/computers/sinclair-zx80/

And the Apple-1 which is also a very elegant solution to the same problem but without some of the drawbacks (it does have video memory but the CPU isn't slowed down much):

http://forum.6502.org/viewtopic.php?t=1352

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