Amiga.org

Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: orange on July 30, 2004, 07:59:46 PM

Title: A1200 hardware specs
Post by: orange on July 30, 2004, 07:59:46 PM

I've decided to check every (damn) resistor on A1200 motherboard hoping to find what makes Alice go hot.

I need some "LIST" with values of resistance, cause reading those small numbers is hard, and I don't understand them anyway (can you help?)

Has anyone done that hack:
http://groups.yahoo.com/group/Amiga-Hacks/message/184
?

I've heard that pullup resistors are usually 10K to 47K?? (470 ohm seems too little?)

Title: Re: A1200 hardware specs
Post by: Stedy on July 30, 2004, 11:12:00 PM

Not sure if this will help, the specification and pinout of Alice can be found here:
Alice spec (PDF) (http://www.thule.no/haynie/chips/aa/lisaspec.pdf)

Interestingly, it can run from -25C to +125C not Mil-spec but very good.

The hack you refer to is one that corrects the timing error on the 7 MHz clocks for accelerator cards, the connection to Alice is to pull DRA0 high.

Search the web and you can find the A1200 schematics, that will have all the resistors.

Have you tried some freezer spray on the Alice ASIC?

Title: Re: A1200 hardware specs
Post by: orange on July 31, 2004, 11:10:07 AM

I'll try that, thanks

Title: Re: A1200 hardware specs
Post by: Xamiche on August 01, 2004, 06:07:14 AM

Hi there,

There are complete schematics for the Amiga 1200, and other Amiga, on this website.

Amiga Schemtaics (http://www.ianstedman.co.uk/Amiga/schematics/schematics.html)

Xamiche
:-)