Call for Help: 3B1 1MB to 2MB upgrade

[Mike Thompson]

>From article <2653 at cbnews.ATT.COM>, by mvadh at cbnews.ATT.COM (andrew.d.hay):
> 
> btw, it looks (from the schematics) like you could piggyback the
> second 2mb on top of the first without much wiring.
> piggyback sockets needed, of course (anyone still make them?).
> 
> -- 
> Andrew Hay		+------------------------------------------------------+
> Holistic Specialist	| I will design a computer for you, so powerful that   |
> AT&T-BL Ward Hill MA	| organic life will form part of its operational matrix|
> mvuxq.att.com!adh	+------------------------------------------------------+

I have been thinking the same thing, but I don't have schematics to
fill in the details.  A long time ago, I piggy backed 16k RAM chips
( it was a very long time ago :-) to bring a 16k TRS-80 color computer
to 32k.  Of course I had to redirect an address line to each chip with a
jumper, but would a simular technique work to bring a 2MB 3B1 to 4MB.

If anyone has done this before with a 3B1, I am sure the rest of us would
like to hear about this.

Mike Thompson

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Michael P. Thompson                      FOCUS Semiconductor Systems, Inc.
net: (sun!daver!mfgfoc!mike)             570 Maude Court
att: (408) 738-0600 ext 370              Sunnyvale, CA  94086 USA
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