Where's the cpu on my 800XL?
Posted:
Sun Aug 22, 2010 10:48 pmby matsondawson
I'm expecting to see a 6502, 65C02, anything like that, but not one chip is labelled as such.
It's broken so I want to chuck a logic analyser on it.
Re: Where's the cpu on my 800XL?
Posted:
Mon Aug 23, 2010 6:13 amby tezza
Matt,
It's a special type of 6502 labelled CO14806. See
http://www.atarimania.com/faq-atari-400 ... ps_13.htmlI was also mystified when I first started to work on Ataris. In fact I'm working on one right now. See..
http://www.vintage-computer.com/vcforum ... -Atari-400 and
http://www.atariage.com/forums/topic/16 ... n-startup/I've ordered a new ANTIC chip for mine, which I'm hoping will solve the problem.
Re: Where's the cpu on my 800XL?
Posted:
Mon Aug 23, 2010 9:58 pmby matsondawson
Tezza,
Do you have a circuit diagram for the 800XL? I've checked the 6502 and it seems to have it's reset line held low, so I need to find out what drives the reset line.
Actually, at start up it oscillates at 1.75Mhz, then settles at low.
Also I noticed the clocks aren't square but very lopsided, do you notice this on yours?
Re: Where's the cpu on my 800XL?
Posted:
Mon Aug 23, 2010 10:48 pmby tezza
Reset line low doesn't sound right.
Anyway, this might help
http://www.classic-computers.org.nz/tem ... rfacts.pdfLet me know when you've downloaded and I'll take it down. It's quite large (15MB).
Re: Where's the cpu on my 800XL?
Posted:
Mon Aug 23, 2010 11:08 pmby matsondawson
Thanks I've got it, and put it up here for others that may need it...
http://mdawson.net/files/800XL-sams-computerfacts.pdf
Re: Where's the cpu on my 800XL?
Posted:
Mon Aug 23, 2010 11:15 pmby matsondawson
BTW that's an awesome manual, thanks!