Date   : Sun, 16 Dec 2007 11:43:38 +0000
From   : jgh@... (Jonathan Graham Harston)
Subject: Adding RAM to a BBC/B

Michael Howard wrote:
> Many moons ago, I came across a project for adding RAM (sideways?
> shadow?) that involved adding a RAM chip (CY62256LL-70PC, I think I
> used), cutiing a couple of tracks on the motherboard and soldering a
> coulple or three fly leads.
 
Probably sideways RAM. A 62256 is 256/8=32K SRAM. Not PCB cutting
is required, just a flying lead to collect WR and a flying lead to
collect a ROMSEL line. See http://mdfs.net/Info/Comp/BBC/SROMs/32K
 
A common sideways RAM module was two 8K SRAMs glued one on top of
another with a NOT gate to select between them, and a flying lead
to collect the WR signal.
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
The most perfect world is an imperfect world as the imperfections
give people a reason to strive to change it.