Date   : Thu, 26 Jun 2003 22:22:33 +0100
From   : Tony <kilm02@...>
Subject: Re: Torch hardware: standard BBC B IC listing needed...

My first post to the list so hope it goes through OK :).

On Thu, 26 Jun 2003 18:01:29 +0100 (BST), you wrote:

>Hi,
>
>just been given enough Torch stuff to... well, to fill a car anyway :)
>
>The 725 system has a BBC (B, I think) at its core - could someone do me
a
>favour and see which of the markings on the following socketed ICs on
the BBC
>board match what's in a standard BBC?
>
>  IC1 =   6502A
>  IC2 =   HD46505SP
>          HD6845SP
>  IC3 =   RS6522
>  IC6 =   408 V 2147
>          VC 2023 
>          201647 
>          (c) Acorn computer

Video ULA

>  IC7 =   Ferranti
>          ULA 2C199E-7

Serial ULA

>  IC51 =  HN613128PB04
>          (c) Acorn computers

IC51 will be the OS, IC52 probably BASIC. (I can't check the numbers
against mine as they were replaced by 256k eproms long ago......)

>  IC52 =  HN613128PB05
>          (c) Acorn computers
>  IC69 =  RS6522
>  IC73 =  NEC D7002C
>  IC78 =  V3420001
>  IC88 =  Torch ROM: ECO 3.35K (c)1983
>  IC89 =  MC68B54P
>  IC98 =  empty socket
>  IC99 =  TMS5220NL

IC98,99 are the speech pack - one is the speech processor and the
other a ROM with various pre-recorded phrases. In mine IC98's a
TMS6100NLL.

>  IC100 = Torch ROM: Unix host V1.00
>  IC101 = Torch ROM: (CIL) MCP 1.22
>
>all chips 28 pins except ICs 1, 2, 3, 69, 78 which are 40 pins. I can't
see
>anything that's obviously been resoldered and may have been a factory
>modification so I'm just worrying about the socketed chips.
>
>Oh, what "normally" lives in the socket for IC98? Does it make sense for
 that
>to be empty? 
>
>I should have spares for the three Torch ROMs; I just want to make sure
none of
>those others are oddball Torch-specific parts (some of them such as the
6502
>and 6522's obviously aren't!) before I try powering the machine up. Just
 in
>case it explodes :-)
>
>I've got spares / schematics / docs for everything on the Torch side of
things
>so I'm OK there (68k, SCSI, MFM boards, RGB and keyboard interfaces
etc.), I
>just don't think Torch documented any mods to the 'core' BBC board -
hopefully
>it's just the three ROMs and the rest of the BBC board is stock.

There's no reason why they should have, one of the best features of
the BBC micro was it's ability to be used like this without having to
be hacked apart. Still best to check first though. If you do get stuck
I could have a dig though some old acorn users for more info.......

Tony.

>
>cheers
>
>Jules
>
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