Date   : Fri, 17 Feb 2006 20:29:27 +0000
From   : Andrew Benham <adsb@...>
Subject: Re: BBC Master real-time clock

Thomas Horsten wrote:

> My problem is about the RTC in the master. It seems to work
> eratically, sometimes when the computer has been switched off the
> month field and minutes get corrupted. So for example now, "*TIME"
> gives "Fri,17 ¥Õ©ª 2017.18:66:11". (¥Õ©ª being ASCII codes 232 and 224).
> 
> I have installed Andrew Benham's Y2K patch but the problem was also
> there before I did so (it'd just show 1917 instead).
> 
> The pattern is the same every time. So I wonder if anyone here knows
> if my CMOS/RTC chip is faulty, or if this is more likely be related to
> the battery being close to dead? My battery pack is 3 Duracell AA
> batteries in a shrink wrap with a "Acorn Approved Part" sticker on it,
> so I guess I could repair it myself quite easily.

Changing the battery pack is well worth doing as a first step.
The battery pack comprises 3 AA cells, a resistor and a diode.
You can either solder 3 cells together, or buy a 3-cell battery
holder.

> On a side note, since I built an EPROM adapter for my Y2K-fixed MOS
> ROM, I'd like to try the "OS 3.50" ROM as well. So if anyone has an
> image of it lying around I'd be grateful for a copy in email.

I'm not sure about copyright issues on the Master ROM image.
It'd be neat to be able to distribute the images with the Y2K
fix already done.  And, while we're at it, with fixed DFS ROM
image too - since Acorn shipped buggy DFS code in both 3.20
and 3.50!

-- 
Andrew Benham         adsb@...       
Southgate, London N14, United Kingdom

The gates in my computer are AND OR and NOT, not "Bill"