New finds: enough Torch stuff to sink a battleship

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Fri Jun 27 18:59:00 2003

> Tony,
>
> an all-in-one email...
>
> > OK, in the production XXX, the hard and floppy drives were connected to
> > an OMTI board, and thence to the SCSI bus. Your unit is consistent with this
>
> Yep, that's exactly what I have. The case may or may not be a stock part. The

My guess is that you have normal XXX boards mounted in a non-standard
case. Possibly the case from some other Torch product.

> XXX case itself looks to be from something else for sure though - there are
> even two spare half-height drive bays inside.
>
> The XXX I have is a single board called a 'Stickleback' with various connectors

Yes, that's standard.

> in it - including BT in/out and an Ethernet port (none of these are actually

The BT connectors are wired to a pin header just behind them _only_. The
internal modem connects to the Xbus (basically BBC 1MHz bus without
interrupts!) header and to the header connected to the BT connectors.

> wired to the back of the case though). There's also markings on the board for a
> VME bus connection, but no socket or associated circuitry.

The VME interdace is a DIN41612 plug and a few buffers. AFAIK all
production machines had it fitted.

>
> I'm "missing" two ICs: IC139 is just a socket for a 48 pin IC beneath which is
> written "WYN8526(ET)". IC140 next to this is a 24 pin socket and is also empty.
> Maybe something to do with the ethernet circuitry? The connector's nearby. (ET
> = 'Ethernet Transciever" ?? :)

Probably. The ethernet chips (I think there were 3 -- 7990, 7992, and a
transdformer) wrer optional.

>
> > The production machines have a 8 pin DIN for video.
>
> OK, I do have that but it's labelled RGB; there's also the hole for a socket

Yes, it's analoge RGB at TV rates + 2 syncs + drive for a piezo speaker.

> labelled 'video' - but as the case is a hack who knows...

It sounds like this case once took a BBC micro board...

>
> > Be careful. This sounds like the case from something else. Production
> > XXXs have 2 DB25 sockets, and both are RS232 ports (one actually carries
> > 2 sets of RS232 signals, for a total of 3 serial ports). There is no
> > parallel port on the production machines....
>
> My Stickleback board is marked as having RS432 and X.25, both on 25 pin ports.

Yep, standard.

> The RS432 port is wired through to the parallel port on the back of the case,
> and the X.25 port is wired through to the RS432 port on the back of the case
> :-)

As I said, be careful!

>
> > Production machines don't have a conventional power switch. The PSU is
> > controlled by a relay. There's a touch-sensitive contact on the front of
> > the box that turns the PSU on when touched.
>
> Except on mine :-) There's a battery hanging loose inside the case, but
> nothing resembling touch contacts; it appears that's all been bypassed on this
> machine and the power switch works conventionally. I wonder what the correct
> procedure of shutting it down safely is... (hopefully one of the various stock
> Unix methods will work)

There's an 8 pin power connector on the stickleback. Is is connected to
anything other than the PSU and the battery? The touch-switch circuitry
is on the PSU board, and sends an interrupt over one pin of that
connector (I can dig out schematics/pinouts if you need them).

>
> [Torch "Hard Disc"]
> > This sounds a bit BBC-micro like!. There is a Torch SCSI hard disk unit
> > for the beeb -- it's supposed to be rather rare. The one I've seen is a
> > plinth to fit under the nonitor contianing the SCSI interface (connectes
> > to the Beeb 1MHz bus) + hard disk and also a floppy drive (connects to the
> > normal Beeb disk controller). Maybe you have much the same unit built
> > into a case with the Beeb mainboard and monitor.
>
> OK, been inside now - it is a BBC, with a Torch Z80 coprocessor. Torch SASI
> interface hooked up to the BBC's 1MHz bus, with a Xebec interface hanging off

Are you sure it's SASI, not SCSI (not that it makes much difference.

> [ Torch-725 ]
> > The QuadX I have is in the same case (basically) as a production XXX. But
> > the mainboard is a singla 6U VME card, and there's a little 3 slot (I
> > think) VME cardcage in the bottom slice. Much the same PSU as
>
> Hmmm... ok, what I have in that 725 is another BBC, a 68k Torch Atlas board,

Definitely not a Quad-X

> Torch SCSI interface, and a Xebec controller talking to the full-height drive.
> I need to go poke around in the documentation sometime. And I'll have to hassle
> the guy I got these from about the rack-mount QX he has if this is in fact
> something different :)
>
> Information on what exactly a Torch Unicorn was would be useful, to be honest.

I thought it was a 68000 coprocessor for the Beeb.

> Some people seem to think it was the name of a complete machine, whilst others
> think it was just the name for the range of Torch cards available for the BBC.
> Just idly wondering if the 725 was a prototype Unicorn or something; I don't
> have details of exactly what machines Torch made.
>
> > This does not sound like a XXXX....
>
> I do have a spare hard disk labelled as Quad X, those tape drives and
> controller boards, a surplus Torch-stock PSU, complete ROM set, and the
> complete schematics for the QX VME card. I'll just go build myself one... ;-)

Good luck in finding that custom chip (oh, what did they call it?) that
handles video, etc...

> I'll keep an eye out when I go through the docs I have. I noticed on the
> previous owner's invoices for the XXX that I now have that he recieved it with
> a tape drive. Maybe there'll be some info amongst everything that says how it
> hooks up. The two tape drives I got were from XXX machines so I can grab model

Oh, it just hooks up to the SCSI bus... It's getting the software sorted
out that's the problem.

Still, it can't be worse than the PERQ3a. On that infernal machine, the
minor device numbers have no relation to the SCSI addresses at all!

> easy enough that I can use them in other systems... I've got the docs for the
> boards but I don't know how detailed they are yet.

The Manta is something I know nothing about, so if you have technical
docs I'd be interested in probing you for information...

-tony
Received on Fri Jun 27 2003 - 18:59:00 BST