20 Nov
2000
20 Nov
'00
9:50 a.m.
--- Tony Duell <ard(a)p850ug1.demon.co.uk> wrote: > >
Oh - must have miscounted :-/
The box in
question is a RML-380Z-D model, with
dual 5
1/4" drives, and I think, 32K RAM. It has
two
video
There is room for 32K RAM (2 rows of 4116s) on the
CPU card. If you have
the RAM expansion card (which, as you imply is a CPU
board with the CPU
and many other chips messing and a different address
decoder PROM) then
you possibly have up to 56K RAM.
I has an address *prom*? I thought it was purely TTL?
I s'pose its hard to tell with all the pretty little
coloured[1] splodges all over the socketed chips
(presumably to aid the people who put the chips in...)
COS = Cassette Operating System, and is basically a
bootstrap loader (for
cassette or disk) and a machine code monitor.
I figured that much out eventually :)
I should have a system disk somewhere, but it would
take some time to find
it.
Kewl - any system disk, even a duplicate is good - at
least one may work.
I also should have the COS user manual (giving
some of the calls,
etc)
In what format? Electronic? (i.e. easily sharable?)
but I don't have the optional source lisitng of
COS (and FWIW, I'm
looking for it too).
As soon as the <insert your own expletive> person who
broke our lab's device programmer fixes it - i'll dump
the COS roms. I managed to dump the disk rom, using
an older programmer - but it wouldn't touch the older,
mainboard devices - It complained of over-current. I
suspect it was not intended to cope with *all* devices
- unlike our really fancy new one - which is broke :(
Yes, or X to boot with the floppies swapped over
(the 'B' drive is A:).
The latter is useful if one drive decides to fail...
How thoughtful of RML :)
There is an LED on the
floppy
Um, no! I know nowt about this box - I'll check the
disk controller very carefully tonight. Its software
is certaining interesting - very wacky code, quite a
bit of it polymorphic - just to hurt your brain :-/
The card *is* on the main bus, and is connected to the
floppy and serial port. It is also stamped (C)RML,
ISTR.
I've a really nasty feeling, this machine has been a
student project, and they used the floppy controller
as a secondary cpu :) Should there be a mostek MT4802
(2Kx8 SRAM) in the socket above the eprom? It doesn't
even occupy all the socket (which is suspicious) and
the ROM does contain memory sizing routines...they're
obvious :) I *really* hope not!
Dave.
[1] Appologies if you think I spelt it wrogn ;0
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controller, it flashes with a kind of 'heart
beat'
pattern i.e.
Flash-flash--pause--flash-flash--pause
Are you sure this is a standard RML disk controller?
I can't find any LED
on the schematics, and I don't remember there being
one when I looked
inside my machine. The standard disk controller is
one card that fits
onto the 50 way 'bus' ribbon cable, and which
contains a 1771 disk
controller (Single density only) and a 8251-based
serial port (device SIO-4)