Date   : Tue, 27 May 2003 20:30:12 +0100 (BST)
From   : Peter Turnbull <pete@...>
Subject: Re: Sideways RAM designs

On May 27, 19:40, Nick B wrote:
> Dom Wright wrote:
>
> >I remember making one, it was quite simple - but now I can't
remember how:-(
> >Some of the static ram chips were pin-for-pin equivalents
(especially the
> >CMOS ones) for the BBC ROMS, all you had to do was bend a pin or two
out and
> >connect them to the R/W line.
> >
> >SRAM chips were available long before the Beeb was about.
> >
> >
> Yes ISTR at that time they were 2114 1k x4, if you wanted more memory
> you had to pay big money or use dram.

Well, that was one well-known type (used in earlier machines, like the
Atom). At the time the Beeb was launched, 4118 1k x 8 chips had been
available for a little while (and were used in Sinclair machines), 6116
2k x 8 were around, and the 6264 8k x 8 came somwhat later (but still
well within the lifetime of the Model B).  All of the above fit a Beeb
sideways ROM socket, but you need to bend a pin out and find a R/W to
connect it, at least.

-- 
Pete                                           Peter Turnbull
                                               Network Manager
                                               University of York