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From: <>
Date: Sun Feb 27 13:35:59 2005

I would start by checking the PSU (as ever). The 4 wire power cable to the
drive has ground on the 2 middle pins and +5V, +12V on the outside 2
pins. Check these with a voltmeter.

Then, you've foudn the EPROM. That's a standard 27128 device IIRC. From
that you can find the data pins on the 40 pin ICs on the board. One is a
6809 of some flavour, another is the floppy controller (I think a
1793-type of thing, maybe a 2793, but I think not). If there's another 40
pin chip, then it's probably a 6821. From the data, and if necessary,
address, pins on the EPROM you should be able to identify these ICs.

OK, now check to see if the 6809 is getting a clock. And what about
reset? Is it attempting to access the EPROM? Is there activity on the
address and data buses?

That should at least eliminate 'sillies'...

Received on Sun Feb 27 2005 - 13:35:59 GMT

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