Date   : Sat, 13 Sep 2008 22:33:30 +0100
From   : jumbos.bazzar@... (Mark Haysman)
Subject: Sideways RAM rom ?

Hi.

With my FRAM modification to the main boards that give 2x16k SWR, they 
require that the SWR latch (FE30) be pointing to them, then a write occurs 
in order for the data to be written, so *LOAD doesn't work. The SRAM 
commands in the Acorn 1770 DFS do the job, so I would suggest something 
similar, or writing a set of short routines to do the same job.

It depends on how you have your hardware setup for write access to each 
bank, the Watford ROM/RAM board uses a range of addresses at FF30 to FF3F to 
select which bank is "write enabled", which is an odd way to do it, but it 
works for them!

Would be good to see this up and running, I presume you've got it so you can 
flash the SWRs in the beeb without having to take the chip out?

Mark.

----- Original Message ----- 
From: "Phill Harvey-Smith" <afra@...>
To: <bbc-micro@...>
Sent: Saturday, September 13, 2008 9:34 PM
Subject: [BBC-Micro] Sideways RAM rom ?


> Hi,
>
> My first post to the list so please be gentle with me :)
>
> I've just updated my design for a fully populated rom board (using a
> 27C010/020 or flash equivelent) for the BBC B, to include a block of
> RAM, to be used as sideways ram, however the standard BBC B does not
> come with sideways ram commands built into the machine. Can someone
> sugest a suitable set of routines for use in such a setup.
>
> Basically my board at the moment will have the roms in banks 8-15, and
> the ram in banks 0-7. My 3 BBC Bs also have Watford 1770 DDFS (one
> original and 2 clones :)  ), in them which I'd like to continue to use
> if at all possible.
>
> Cheers.
>
> Phill.
>
> -- 
> Phill Harvey-Smith, Programmer, Hardware hacker, and general eccentric !
>
> "You can twist perceptions, but reality won't budge" -- Rush.
>
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