TRS-80 (IV) help? - test-drb@ccmp.vtda.org

12 Oct 2004

Hi Tony,

...
 My guess is that it's not talking properly to the
1793 disk controller 
chip. I have had this chip fail :-(. But you might start by checking the 
power supply (there's a second PSU board in disk units, mounted on the 
side of the drive tower, which supplies the disk controller board and 
drives). And then check and re-check that ribbon cable. 
I have determined that it is indeed the 1793 disk controller chip ...
I borrowed one from another system, and as soon as I powered up, I heard
the floppy seek to track 0 - stuffed in a boot disk and it booted right
up...

I agree :-( .. I don't have a spare 1793.

Does anyone have an extra Western Digital 1793 (or compatible) FDC
kicking around?  Bare on on a board (I've got a good desoldering
station) ???

Regards,
Dave
-- 
dave04a (at)    Dave Dunfield
dunfield (dot)  Firmware development services & tools: www.dunfield.com
com             Vintage computing equipment collector.
                http://www.parse.com/~ddunfield/museum/index.html