Hi folks:
I recently got two Osborne 1 computers. The first one (blue case) had a
dead power supply -- I fed +5/+12 DC power into the battery connector
and was able to bring it to life, but had no software to test it
further. This one has a double-density option board inside (and drives
I presume), as well as the optional modem.
I also got a second osborne (early beige case), which came with software
and manuals. This one has a keyboard that seemed to have a stuck key.
Turns out that the keyboard matrix has many shorts, not only
row-to-column, but also row-to-row and col-to-col. It is a flex-circuit
soft of design, and it appears to have a silk-screened or deposited
metallization pattern for the matrix. There is an insulating layer of
some sort and then a second metal layer. Anyway, it seems that the
insulation between layers has failed where some traces cross. It'll be
a mess to fix, if even possible. Anyone else have this problem on an
early keyboard?
Uh-Oh ! I picked up a beige Osborne 1 last summer. It's in my
lengthening To-Do queue. I booted it at the time but it had a problem
not recognising the keyboard. I simply figured it was likely a cable
fault. Now I wonder if there may be larger problems with the
keyboard. What was your methodology to check the k-b ? I don't
want to open mine up now to do a visual inspection, lest I be
captured by the "fix-it" bug and neglect more pressing tasks.
Lawrence
So I plugged the later keyboard into the early unit,
and was able to
boot cp/m. I tried to copy the original cp/m disk to a new one, but
copy had read errors on a couple of tracks. I could see some
visibly-crappy spots on the disk surface too, but it did boot fine, and
the utils seemed to run ok. So I formatted a new disk, copied just the
system, and then pip'd the files over. Hmm, no errors on file reads
with pip -- does that make sense, since copy previously found bad
tracks? After booting and running off the new disk, it seems that all
command files are working, with the possible exception of movcpm (which
seems to hang the machine, though I am not sure how it works).
So I finally got the original disks copied, and learned a bit about the
machine in the process.
I fired up the later (double-density) model, but it would not boot from
the single-density disk. Should the DD drive be able to read the SD
disk? The drive was making an odd noise, so it may be drive-related.
Is there a way to boot from drive B? Can I swap the drives, and if so
are there master/slave jumpers, or terminations that need to move as
well? On the early machine, there was a diagnostic mode in rom (ctrl-D
at the boot screen, I think it was), but the newer unit does not respond
to that. Were diagnostics removed from later roms?
I swapped the working power supply from the old unit into the new
machine (yes, I know about the different jumper/harness connections).
It worked fine.
Then, I put the non-working power supply into the early unit, and it
started working! I think the original power supply problem in the newer
machine may have been an intermittant in the fuse/voltage-selector
gizmo, which tells the PS whether to expect 115 or 230 -- in the early
unit, this gets hard-coded by the jumper wire on the PS board. Crazy
frickin' computers.
Then I accidentally cracked the brightness trimpot on one, as I put
things back together. Tacked a temporary pot in place while I look for
a replacement. I shouldn't try to do this stuff at 2 in the morning, I
guess.
Well, that was sort of an FYI ramble, but any thoughts appreciated.
Does anyone have double-sided software for sale or trade?
thanks,
gil smith
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