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From: gnome@oliveb.UUCP (Gary)
Newsgroups: net.micro.att,net.micro.pc
Subject: 6300 display controller disable
Message-ID: <1071@oliveb.UUCP>
Date: Fri, 22-Aug-86 20:36:21 EDT
Article-I.D.: oliveb.1071
Posted: Fri Aug 22 20:36:21 1986
Date-Received: Sun, 24-Aug-86 05:02:38 EDT
Distribution: net
Organization: Olivetti ATC; Cupertino, Ca
Lines: 27
Xref: mnetor net.micro.att:1412 net.micro.pc:6260

> To put in another graphics board you must first disable your present board. To
> do this you remove a 74LS00 chip located on the bottom middle of the graphics
> board.  It is above where the +5 volts and ground wire connect. In newer
> machines it is in a socket on older ones it is soldered in. NOTE this will
> void your warranty if you do it yourself! After removing the chip then pins 7&6
> must be jumpered together and 3,8,11,14 must all be tied together.  We got
> this fix directly from AT&T. We just bought 300 of these units and some will be
> modified.

> All the usual disclaimers, ect...
> 
> Paul L. Marcuzzo
> Penn State University

Well, actually, on REV P4 boards (theoretically all rev's that don't
have the 3-pin disable jumper) you should try removing the LS00 and
connect 3,11,14 together and 7 & 8 together.
This should disable both the IO and memory address decoders and leave
the bus clear for other display controller cards.

You shouldn't be able to boot-up with the other configuration...

Gary

>- Usual disclaimer -<

(hplabs,allegra,ihnp4,glacier)oliveb!oliven!gnome