Date   : Tue, 20 Oct 2009 12:14:59 +0100
From   : bbcmicro@... (wookie)
Subject: SRAM on the BBC+ 64K

Hi

Following on from the discussion on cheap ROM upgrades for the beeb, I 
was wondering, since to BBC+ can take 32K ROMS/EPROMS can I stick a 32K 
SRAM chip in there and hook up the extra leads needed to make it work as 
sideways RAM ?

What spec of SRAM would I need, i've found the following in a 28 pin 
package, will it work ?

Part Number = KM62256ALP10
Manufacturer Name = Samsung Semiconductor
Description = General-Purpose Static RAM
Number of Words = 32k
Bits Per Word = 8
t(acc) Max. (S) = 100n
tW Min (S) = 100n
Output Config = 3-State
P(D) Max.(W) Power Dissipation = 1
Nom. Supp (V) = 5
Package = DIP
Pins = 28
Technology = CMOS

As far as I can tell the pinout is correct...

A14-1  28-Vcc
A12-2  27-NOT WE
  A7-3  26-A13
  A6-4  25-A8
  A5-5  24-A9
  A4-6  23-A11
  A3-7  22-NOT OE
  A2-8  21-A10
  A1-9  20-NOT CS
  A0-10 19-D7
  D0-11 18-D6
  D1-12 17-D5
  D2-13 16-D4
Vss-14 15-D3

Cheers
Wookie.