10 Jan
1999
10 Jan
'99
2:24 a.m.
On Jan 10, 11:10, Andrew Davie wrote:
First question: there are two drives, and each has a
set of jumper pins.
The pins are labeled..
DS 0
1
2
3
MX
MS
H M
H C
The top drive, on which the red LED lights when I power the drive, has
jumpers across DS1 and HC. I am guessing that this drive is the second
drive, and that the two jumpers that fell out of the casing belong on the
second drive. That should be, I'm guessing, DS0 and mmmh... HM? Can
anybody enlighten me on this?
Probably DS0 (Drive Select 0) and all other links the same as the other
drive (so HC, rather than HM -- that determines the behaviour of head
loading w.r.t. drive select/motor on/some other condition)
Second question: Powering the Sorcerer (I thought I
didn't have a
monitor,
but the VIDEO IN on my VCR works nicely - it shows up
well on my TV)
exibits
some strange behaviour. What's trying to come up
on screen is "EXIDY
STANDARD MONITOR" and a few lines after that. But it simply stops after
the
second or third character. Repeated efforts see it
stop in different
places - sometimes you see the whole lot, and it's actually usable for a
few
[...]
I found a homebrew cartridge for this machine, and
when its plugged in,
the
wordprocessor it contains appears to work fine -
everytime - with no
apparent problems.
So, the question is, what's wrong with the
monitor?
Did you have a BASIC cartidge plugged in? If that were so, and it were
faulty, it might well interfere with what happens after a cold start.
If not, it could be a faulty monitor PROM. I can't remeber at what point
the monitor checks for a cartridge and hands over control, but it could be
that one of the monitor PROMs is faulty. That might only be visible when
no other cartridge ius fitted, and the CLI part of the monitor is executed.
Third question: Assuming I actually get the machine
powering up
correctly,
and that the drive I have isn't missing some vital
component - it will be
time to insert a disk. Can anybody tell me how to actually use a drive
with
the Sorcerer system? I'm afraid it's going to
be some arcane "GO C800"
or
something like that, from the monitor. I think I
might need someone with
documentation!
That's how they usually work, but there are lots of different Sorcerer disk
formats/systems. We'd need to know more about the specific disk system you
have. Usually the bootstrap is quite small, and in the area you mention;
you could probably find the start of the bootstrap code just by DUmping
memory and looking for it.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York