4 Jul
2005
4 Jul
'05
5:37 a.m.
On Mon, 2005-07-04 at 04:13 +0100, Tony Duell wrote:
That's what I'm thinking of :) I haven't seen their contents noted down
anywhere. My programmer here might well handle them, I just don't want
to risk toasting one out of a running machine!
Indeed. I suppose given a dump of the ROM out of my 480Z disk unit, plus
the schematics for the board, and the 480Z details it would be possible
to figure it out - but somewhat time-consuming.
I just pulled the lid on my disk unit and it definitely has all the
right bits to be the intelligent disk controller; it's just missing all
the circuitry to interface to the 380Z bus (it just has all the serial
side of things present + the Z80 part of everything)
It's in the COS 3.4 Information File - under misc functions (reset and
initialisation):
"COS checks to see if there is a VDU plugged into the SIO-4 socket. If
there is, all subsequent output via the scroller output EMTs is sent to
this VDU. Graphical output, such as the front panel, or low or high
resolution graphics, still appear on the RML screen. If a character is
received from the VDU at 9600 baud, COS also switches the keyboard EMTs
to take all subsequent input from the VDU ignoring the RML keyboard."
So it should work with an SIO-4 (or presumably 4C). Indeed, we've
actually got some Cifer terminals doing nothing which have nice black
keyboards very similar in looks to the 380Z ones...
The text implies that it's not possible to have a terminal as input-only
though; it'll always redirect text output if a terminal's present. How
much RML software actually uses the COS routines is another matter -
there must be at least some bits and pieces out there that talk to the
keyboard / display directly rather than through COS, and those then
wouldn't work...
Heh, I know what you mean! In the case of RML stuff I like to try and
keep track of who has what anyway as it's reasonably uncommon stuff.
cheers
Jules
There are only 2 boards. The 8" controller is the
same as the
non-intellegent 5.25" one. There are notes on the schematic for the link
settings for the FDS (== 8") and MDS (== 5.25") versions.
Not me yet... more interested in their SASI controller at this stage to
be honest as I really need a way of getting the 380Z fileserver backed
up!
Far as I know, the former board is FM only and
can put about 70KB on a
The 1771 is certainly FM (single density) only.
disk, whilst the latter one can do MFM and gets
about 240KB on a disk.
I've not seriously looked at those schematics yet... Actually, info
on the various PAL chips would be handy; RML didn't half
THere were no PALs in the original set of boards (CPU, VDU, hi-res, disk,
etc). WHat there were -- and were to excess -- were small bipolar PROMs.
Those were often colour-coded. Aha, I've
got a 480Z disk unit here - never tried it as I need to sit
down and figure out the cable wiring which puts a bit of extra time on
the task.
It would be useful to know the protocol that the 480Z uses to talk to the
disk unit. From what I remember, though,, it uses the serial chips in
synchronous mode, which means finding another machine that could act as a
disk server would not be totally trivial. that way.
Hitting a key on the terminal at system start should be enough
to wake things up and tell the 380Z to use the terminal as input rather
than the usual keyboard. Can't remember if there's a way of telling it
Are you sure about that? I've never seen it documented anywhere. I'll
double check regarding tapes. I've got about half of Bletchley's
Thanks. But absoutely no hurry -- this is very much a 'to do sometime'
project, and it's been on the list for many years!