Wizztonics TOS206 upgrade issue - SOLVED

[Bikerbob]

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So again.. some new hardware...

No find on the net anywhere so far. No instructions.. no docs or software.

At the moment this machine.. only the two chips shown... not sure if those are custom ROMS with both 1.04 and 2.06 on it. I am assuming.

Switch on back has a closed, and open.. not a double throw. SO I assume 1.04 is default, 2.06 is closed.

Anyway.. 1.04 - get a white screen and floppy access ... thats all.

2.06 I get the atari logo in the top corner, no floppy access and thats all.

Any help would be very welcome.

James

[Maximilian]

Have you tried asking Wizztronics for the manual?
http://www.wizztronics.com/ataricomputers.html

[Bikerbob]

Yep, no response so far.

James

[DoG]

Do you have a diagnostic cartridge to test it with?

[Bikerbob]

The computer.. yes! actually I do now!

I have the exxos cart. SO I will try that tonight anyway.. Thanks just brand new to me.. and I know its upgrade related, so never thought to try the cart.

James

[Bikerbob]

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This is what I got.. So T4-- Video Counter Error. The memory controller is not generating the correct addresses for the display.

I have a mega ST2 rev 1 board.. not sure where the MMU is .. it calls it a GST MMU.. but on a rev 1 is it that chip? anyone?


James

[Bikerbob]

I have a C1001509 mmu.. I pulled it.. examined it.. and put it back in.. still no good.

DO I replace it with the same chip?? I read from exxos last upgrade IMP chips maybe no so good. Can i replace with a different mmu?

I have 3 other machines right now.. can I sub in another with this odd board? are the MMU interchangeable?

James

[DoG]

Do a RAM check on the diag cart. Does it say 'OK'?

[Bikerbob]

Cant get to a ram check.

The red screen means it failed on boot. T4 is as I said.. I need to sub in another mmu I guess.. see if we get past this point.

Exxos.. what chips can I sub in for the C1001509??

James

[exxos]

Exxos.. what chips can I sub in for the C1001509??

Would need to see a image of the RAM area. I have a load of RAM chips not in my store yet as well, just not got time at the moment to test them.