Date   : Sat, 06 Jun 1992 19:50:55 BST
From   : RWF Whitehand <R.W.F.Whitehand1@...>
Subject: SW RAM wiring

Forwarded from my Co-SysOp (Martin Ebourne), hope it is of use!:-

>      
>     Yes, I do use a 62256 (or any one of a number of variants of it).
The pins 
> to use are in your Beeb at home. Anyhow, specially for him (hope he 
> appreciates this!) I shall work them out....[Hang on a few mins...] 
>      
>     Right. Here we are. For 16k, just take pin 27 (notWE) to the Beeb R/notW 
> or notWDS line anywhere. I tend to use IC73 (A>D chip, 7002) pin 24 (5th
down 
> on right) because it is a big chip which it is easy to find! If he wants two 
> banks (32k), ie. has a brain cell, then for non-ROM board compatibility
taking 
> up only one socket, take pin 1 (A14) to a random pin on IC76. (Little
one, SW 
> corner.) I particularly recommend pins 11 or 12 since then it stands
a chance 
> of working! (If it doesn't, then it ain't my fault - honest!) If he has
a ROM 
> board, then it will need 2 slots. Put the RAM in one, & take A14 to the
notCS 
> pin of the other. Obviously the pins which are wired to somewhere else
need to 
> be non-inserted into the socket. It is advisable to butcher an IC socket and 
> put the RAM in it. (Not that I always do!) 
>      
>     Of course, if has has a ROM board, it might not work. Depends on
the type. 
> The cheapo watford thing works with the last technique, as most prob. will, 
> but ones which add lots of RAM & take control (ie. sensible) don't work at 
> all. (eg. Soli 256, poss. watford ROM/RAM card thingy - that is a rip-off of 
> the Soli board, and a bad one at that!) All other pins, of course, go to the 
> respective ones in the socket. 
>      

Richard.

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 SysOp: Richard Whitehand - R.W.F.Whitehand1@...
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