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Date   : Fri, 20 Sep 2013 12:05:54 +0100
From   : bbc@... (Dave Curran)
Subject: Early BBC MOS EPROMs

Ah yes, my combined image matches the MOS 010 image on mdfs.net.

That's answered that question.

Not sure why it doesn't work though. Next time I dig out my issue 3 model
A, I'll see if it works on there.

Thanks,

Dave


On 20 September 2013 11:41, Ed Spittles <percy.p.person@...> wrote:

> Looks like OS 0.1, according to
> http://www.stardot.org.uk/forums/viewtopic.php?f=3&t=4542
>
> If it doesn't work, it might even be a pre-production version.
>
> Cheers
> Ed
>
>
>
> On 20 September 2013 10:36, Dave Curran <bbc@...> wrote:
>
>> I've been going through a pile of used EPROMs I got on ebay a while ago
>> and have found 4 2732 EPROMs labelled 'C', 'D', 'E' and 'F'. It was mainly
>> 27128s in the box, and that was what I was after at the time. I remember
>> looking at the time to see if there were any marked 'A' and 'B', so I just
>> assumed they were an incomplete set from something and put them to the back
>> of the box.
>>
>> Now I'm after some 2732s I thought I'd check what was on them. The
>> following string stands out:
>>
>>  :
>>  :   (c) 1981 ACORN Computers Limited
>>  :
>>  :
>>  :   BBC Microcomputer Machine Operating System (MOS)
>>  :
>>  :
>>  :   Change record:
>>  :   032 12-Aug-81 PB     Swop '_'
>>
>> Above that it says OPT MOS70.
>>
>> I then twigged that there probably wasn't an A and a B, and the CDEF must
>> refer to C000-CFFF, D000-DFFF etc. and I remembered reading about early
>> BBC's having the OS on 4 EPROMs. I think there is a way of arranging the
>> jumpers to set the board up for this (may just have been the early
>> issues?). Anyway, I was interested to see if they worked so rather than
>> work out the jumpers, I combined the 4 images onto a 27128 and put it into
>> a BBC in place of OS 1.2.
>>
>> It beeped (but the beep didn't stop) and the screen showed
>>
>> BBC Computer 32K
>>
>> No language ROM?_
>>
>> So I put in back the BASIC ROM and tried again
>>
>> BBC Computer 32K
>>
>> BASIC
>>
>>
>> ?_
>>
>> No response from the keyboard and the beep doesn't stop, so I presume
>> some of the device addresses or OS entry points might have changed.
>>
>> Just wondering if there is a copy of this in an archive somewhere or if
>> anyone is interested. Doesn't seem to be usable on the issue 4 board I
>> tried it on, but might be of interest to someone?
>>
>> The ROM ends with
>>
>> (C) 1981 Acorn Computers Limited.Thanks are extended to the following
>> people, companies and locations, contributors (among others too numerous to
>> mention) to the development of the BBC Computer:David Allen,Bob Austin,Ram
>> Bannerjee,Paul Bond,Allen Boothroyd,Cambridge,Cleartone,John Coll,Computer
>> Laboratory,Chris Curry,Designers of the 6502,Jeremy Dion,Tim Dobson,Joe
>> Dunn,Paul Farrell,Ferranti,Steve Furber,Jon Gibbons,Lawrence Hardwick,Dylan
>> Harris,Hermann Hauser,Hitachi,Andy Hopper,ICL,Martin Jackson,Brian
>> Jones,Chris Jordan,David King,David Kitson,Paul Kriwaczek,Peter
>> Miller,Arthur Norman,Glyn Phillips,Mike Prees,John Radcliffe,Peter
>> Robinson,Richard Russell,Kim Spence-Jones,Graham Tebby,Chris Turner,Adrian
>> Warner,Wilberforce Road,Roger Wilson,Alan Wright.
>>
>> Which seems to differ slightly from the message in the OS1.2 ROM:
>>
>> (C) 1981 Acorn Computers Ltd.Thanks are due to the following contributors
>> to the development of the BBC Computer (among others too numerous to
>> mention):- David Allen,Bob Austin,Ram Banerjee,Paul Bond,Allen
>> Boothroyd,Cambridge,Cleartone,John Coll,John Cox,Andy Cripps,Chris
>> Curry,6502 designers,Jeremy Dion,Tim Dobson,Joe Dunn,Paul
>> Farrell,Ferranti,Steve Furber,Jon Gibbons,Andrew Gordon,Lawrence
>> Hardwick,Dylan Harris,Hermann Hauser,Hitachi,Andy Hopper,ICL,Martin
>> Jackson,Brian Jones,Chris Jordan,David King,David Kitson,Paul
>> Kriwaczek,Computer Laboratory,Peter Miller,Arthur Norman,Glyn Phillips,Mike
>> Prees,John Radcliffe,Wilberforce Road,Peter Robinson,Richard Russell,Kim
>> Spence-Jones,Graham Tebby,Jon Thackray,Chris Turner,Adrian Warner,Roger
>> Wilson,Alan Wright.
>>
>> Thanks,
>>
>> Dave
>>
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>>
>
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