Date   : Thu, 26 Jun 2003 18:01:29 +0100 (BST)
From   : Jules Richardson <julesrichardsonuk@...>
Subject: Torch hardware: standard BBC B IC listing needed...

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
  IC7 =   Ferranti
          ULA 2C199E-7
  IC51 =  HN613128PB04
          (c) Acorn computers
  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
  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.

cheers

Jules

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