At 21:16 12/01/2003, you wrote:
Part 1:
[...]
So: 5pm, trip to Maplins to get the components. "Sorry guvnor, no
diodes in
stock". OK - fall back to the plain X1541
then; at least it'll work on my
That figures... Maplin rarely have useful components in stock in the
shops any more. They were out of stock of 10k resistors one time I needed
them.
They seem to have really gone downhill in the last few years; I suspect the
passing of Tandy has something to do with this - why should they care,
there is no national competition. :(
again, the
traffic jam was horrendus, so glad I didn't. Arrived home,
found
most of my soldering gear, except the tin of
excellent tip cleaner/tinner.
I am trying to work out why your soldering iron was not on your bench
where it should have been. Unless you had taken it somewhere for a field
repair, of course.
Sad to say, I don't do anything like enough electronic
assembly/disassembly. This is only the second time I've used the iron since
I moved here over a year ago. Plus the fact that anything which could be
described as a bench is currently fully occupied with computers and/or
peripherals of some description...
I still haven't fixed up that 8032 yet (it lurks in the cupboard awaiting
my attention), and I've got a project 3032 as well now - this is the one
which started up stuck in the monitor routine the other day, but when I
tried it again this morning the screen is just blank. I know the video side
is OK, as if you let the tube warm up, then power cycle it, you get the
garbage characters for a second or so, then it clears to blank. I've
re-seated all of the smaller chips to no avail; will try the big chips
tomorrow, after that it's a crash-course in microelectronic diagnosis.
Indefinitely postponed, knowing me.
Nevermind,
tip's still clean enough. Apply vice to desk, start soldering
6-pin DIN. Amazingly, I didn't completely wreck it (although some of the
pins needed realigning afterwards). *Surely* there's an easier way??
Sticking the pin-bit into a 6 pin DIN socket helps a little. Using a good
soldering iron also helps. But I agree, DIN plugs are painful to wire,
and mini-DIN plugs even more so.
Hmmm. I actually had less trouble with this one than I've had in the past,
possibly because the solder actually stuck to the pins this time. Mostly
the pins seem to gather crud like there's no tomorrow, then the solder
won't grip, and you end up melting a pin right through the plastic. Grr. I
mean, all they have to do is make the plastic bit out of bakalite - problem
solved.
First, I try the disk in an 8050: No joy. So, back downstairs, pick up the
One of the most stupid design decisions in the CBM drives was that the
8050 was not even read-compatible with the older, 40 track, drives like
the 4040.
Agreed.
Open 3040 up,
it looks like an electrolytic cap has burned out (literally,
It's normally tantalum (electrolytic) capacitors that do this. I've had
many of those explode...
Hmm. It's presently unidentifiable (just a black smear on the circuit
board). I'll stick a photo up soon, and hopefully someone with a 3040 can
identify the component for me for replacement.
Thing is, did the tantalum cap blow because it was old, or because
something else was awry?
place. I cleaned the heads. Worked fine, and still
works. So you might
want to clean the heads on the 4040...
Good point. It was one of the things on the list, but has been postponed
following actually getting it working.
1) Is it
actually possible to copy files from one unit (i.e. diskdrive) to
another (i.e. Shark)? The COPY command can't (it even says so in the
As I meationed eaelier, the COPY command really runs on the processor in
the disk unit (the Commodore floppy drive units contain 2 6502s, one to
run the DOS and handle the IEEE-488 port, the other to actually handle
getting bytes to/from the disk [They communicate via a shared memory
area, one of the features of the 6502 is that you can clock 2 of them
together, one with an iverted version of the clock, and they will happily
interleave accesses to memory]. This means that the COPY command can only
copy between drives in the same disk unit.
Yes, I'd guessed that was why. It's a shame (but, nevertheless,
understandable why) Commodore didn't implement routines to allow unit-unit
copying. However, when hard-disks are concerned, I'd have thought it was
essential to be able to copy to/from floppy unit to HDD unit. Maybe someone
with a 9060 drive (or the other one, who's number I forget) could see if
there's any CBM utility to copy files? If so, any chance of a copy of it?
I guess there must have been programs that read a file
from one disk into
the PET's memory, and then write it out again to another disk (possibly
in a different unit).
I would assume so. I've not really gone looking for one yet, but will do.
--
Cheers, Ade.
Be where it's at, B-Racing!
http://b-racing.com