5 Jul
2005
5 Jul
'05
1:56 p.m.
On Tue, 2005-07-05 at 20:13 +0100, Tony Duell wrote:
IIRC Torch made a SCSI controller for the Beeb, it was used with a ROM
called SCISFS. If you've found one of those you're very lucky, I am told
that fewer than 100 were made.
Hmm... my Torch 725 has a Torch SCSI board in it - although I recall
that it's not a complex board at all, just a handful of TTL chips.
Whether that's the same board as available from them for the BBC I don't
know, but as the 725 uses a BBC as the I/O processor it's reasonable to
suggest that it is. I'll have to check what ROMs it has... (it's got
one of the Torch 68000 coprocessors in it and should run Unix - *but* I
have a feeling that the hard drive's toast and I don't think it's
something I have media for)
The big brown-cased C-series machines that had hard disks in used a
Torch SASI board; I expect those are somewhat more common...
Can't remember what make the bridge board is now, but yep, it's one of
the common ones. The controller shouldn't be doing anything funny with
signal lines or the data, but I thought I'd check!
Nice - I've not seen one of the PIO boards before. And agreed, I don't
think there's a PROM on the standard FDC either.
What about hacking around with the Acorn SASI
controller, e.g. the one in
your ACW? I assume you have schematics, etc for that.
Yep, could do - plus I've got the schematics for the Torch one
somewhere. Just wanted to check that there wasn't anything funny about the RML one
(there shouldn't be) - SASI should be SASI no matter what.
IIRC the RML hard disk unit used a standard ST506-interfaced drive and a
standard bridgeboard to SASI (Xebec?) In which case the host adapter is
going to be pretty normal too. From what I
remember there are no PROMs on the standard (non-intellegent)
disk controller or
on the PIO card that I have somewhere. The latter is a
board with an address decoder, 3 Z80-PIOs and a Z80-CTC on it, along with
a wire-wrap area. I don't have schematics, but it would be trivial to
work out. It should be piossible to work out what COS looks for
from the source
listings. I am not sure, though, if the version on vt100.net is recent
enough to support this. It's a pity nobody has the COS 3.4 or COS 4.0
listings.
Hmm yep, that is a shame. I think a lot changed between COS 3.0 and
3.4...
I still wonder if the PC keyboard interface would be a
good idea. It
would have an adantage to you that the public at Bletchley could bash
away on a PC keyboard without risking anything too rare.
Yep, that is a good point. Mind you, we've got a couple of VT220s with
dead LOPTs - they'd make nice input-only devices!
cheers
Jules