[Techtoolslist] 9100A motherboard revisions...

[John Robertson]

I have six of these things in the shop right now and was noticing the 
revision numbers on the logic boards. The first I have is Rev. C going 
up to Rev. G-1 - which is the interesting one as it allows for HD 
floppies. This revision is a small series of jumper wires and a three 
cuts to the group of traces just to the right of the  Floppy Drive 
connector.

The other revisions appear to only relate to parts mounted on the boards 
- different brands of connectors, reset switch changed, etc. as all the 
ICs stayed the same  as far as we could tell by an eyeball examination.

Making these changes does appear to enable 1.44 drives on revisions that 
previously only had 720 drives so I am going to write it all up - but 
for now you can look at the pictures of the jumpers and cuts and try it 
yourself...I believe you need the 40 meg version of the Bios installed 
as well (2 X 27512 Eproms).

ftp://ttl.arcadetech.org/TTL/Test_Equipment/Fluke/9100A/Photos

I will add Rev. C photos later so you can see the differences.

If anyone has anything later than Rev. G-1 please get in touch in case 
something else was added....

John :-#)#