Date   : Fri, 01 Jul 2005 21:29:13 +0100
From   : Sprow <info@...>
Subject: Re: Sprow- 'tricking' the MOS on a Master 128

In article <004901c57cf2$68592650$0100000a@...>,
   Raf <rafg1@...> wrote:
> Robert,
>
> Is it possible to simulate a write situation to location &9881 in 
> ROM 15, say using the ROM Polling Semaphore?

Couple of problems there, the MOS ROM is read only (being a mask ROM, plus
no nWE signal), and the ROM polling semaphore

> I wonder if we can get to get the MOS to think that it is holding
> &20 there (as BCD) rather than &19. I am hoping that this may
> change the century on the Master's clock from 19-- to 20 --

Better still, extend the range to 1800-2199 with Doomsday
 http://www.sprow.co.uk/bbc/doomsday.htm
Cheers,
Sprow.