[Techtoolslist] 9100A motherboard revisions...

[John Robertson]

Andre Huijts wrote:

> Checked mine, I have revision E.

>

> Nice investigation work.

>

> I've got two Eproms 27512, the hand-writing says V5. Is that the latest version ?

>

> André

>   


Hi Andre,

Yes, V5 is the latest that I am aware of. It allowed 40BM or larger hard 
drives and (I think) allowed the system to recognize other 1.44 floppy 
drives.

The revisions I did to my other motherboards (to bring them all up to 
G-1) seem to work. I have yet to test them with 1.44 floppies and not 
sure exactly what that revision does as it affects line 16 for the 
floppy which is motor 2...perhaps that was needed to allow more drives 
to work with the motherboard.

I'll update the revision info on Monday when I get back to the shop so 
others can play with it if they so desire.

John :-#)#

>

>

> Op 8 jan. 2013, om 03:48 heeft John Robertson <jrr at flippers.com> het volgende geschreven:

>

>   

>> 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 :-#)#

>> _______________________________________________

>> Techtoolslist mailing list

>> Techtoolslist at flippers.com

>> http://seven.pairlist.net/mailman/listinfo/techtoolslist

>> FTP site is: ftp://ttl.arcadetech.org

>> Archive site: http://seven.pairlist.net/pipermail/techtoolslist/

>>     

>

> André Huijts

> andre.huijts at upcmail.nl

>

>

>

>

>

>

>

>