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Any Osborne I gurus?

Dave - is that the "Preliminary Service Manual? from SAMS? It's 6 pages long? I've got that, as well as the Osborne I Technical Manual (586 pages), the SAMS Board, Drives, and Monitor schematics, and that Astec PSU manual.

What's the location of the Field Service Manual you found? Edit: I did find a "field service manual" at kev.pulo.com.au, but it starts at Chapter 6 and only covers assembly/disassembly.

After lunch I'm going to see if lightly "flexing" that logic board makes any difference. It seems the only thing that would be "different" when I turned the unit from upside down to rightside up.

T.
 
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Tom,
It's probably close to the technical manual but has very good tips on repairing and what to look out for. You should review this carefully. I can't find it again after a web search, but I did make a copy of the pdf file.

1983_Osborne_Field_Service_Manual.pdf

Make sure you heed recommendations like "Be sure there is a 1 in. Length of doubLe-backed tape covering the "y" pattern on the soldered-side of the Power Supply."

Also make sure screws are not to long and touch things underneath that they should not. Before you reconnect connectors, examine then for bent or broken pins, etc.
 
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Definitely agree on that "intermittent problem" -

After my one successful boot, I've now had:

BOOT ERROR after trying system from A or B drives, followed by one or more of the following:

screen flashing on and off
high pitch squeal (board? drive?)
"clicking" two or three times from drive (?)
random drive activity

After the successful boot and run with system inverted, I had righted the system and got the BOOT ERROR message.

Then tried restarting *while lightly lifting up on logic board, center at edge*. System again booted and ran perfectly.

But a repeat of the same lifting action wasn't successful second or subsequent times.

Still get BOOT ERROR from whichever drive I try to boot from.

Puzzling.
T.
PS - thanks for the pdf file Dave. Downloaded it from you.
 
And of course, here's a new twist. I just switched the single plug cable to the middle jack on the PSU. System actually ran fine, loaded system and all help files, even read dir of B drive.

Tried loading dbase from B drive; got "bdos error"

Reset system. Tried booting exactly the same way (A drive); got BOOT ERROR.

Edit: how can I clean the drive heads w/o a cleaning disk? Can I just put 70% isopropyl alcohol on a q-tip and carefully rub over the head inside? (if I can reach the head?)
 
NutmegCT said:
Definitely agree on that "intermittent problem" -

After my one successful boot, I've now had:

BOOT ERROR after trying system from A or B drives, followed by one or more of the following:

screen flashing on and off
high pitch squeal (board? drive?)
"clicking" two or three times from drive (?)
random drive activity
Click to expand...

This is not good! It may mean possible shorting of power to various subsystems. With too much shorting the power supply may be damaged. You are in a difficult position. With the system buttoned up, it is hard to troubleshoot, but opening the system may make the symptons go away.

Think carefully about what you want to try next. Do not be rash. You are too close to getting this thing to work.

I'd like to hear from others but I would consider a very careful inspection of the power harness and connectors. Do you know how to ohm-out cables for proper connections?
-Dave
 
dave_m said:
This is not good! It may mean possible shorting of power to various subsystems. With too much shorting the power supply may be damaged. You are in a difficult position. With the system buttoned up, it is hard to troubleshoot, but opening the system may make the symptons go away.

Think carefully about what you want to try next. Do not be rash. You are too close to getting this thing to work.

I'd like to hear from others but I would consider a very careful inspection of the power harness and connectors. Do you know how to ohm-out cables for proper connections?
-Dave
Click to expand...

Not good at all. The fact it worked when flexing the board a little suggests a connection problem somewhere (dry solder joint etc.). These are the most frustrating of problems.

Tom, consider also that the boot problems may have zapped your disk. This happened to me with my osborne when I had the drive problem (which was also intermittent). When the machine crashed, the drive lights often flashed on and off, screen became garbage and random beeps occured. And on occasions the disk was toast, even though it was read-only.

Make sure you have plenty of backups.

Tez
 
"Do you know how to ohm-out cables for proper connections?"

Just guessing again, but doesn't that mean to check for continuity? (I've actually done that for the power cable, both the single-jack and the double-jack cable. All tests for proper continuity.)

Or does that mean something on a higher level, like checking the resistance between specific pins for specific ohm readings?

By the way, that BOOT ERROR is the same message I get if I try to boot from an empty drive. The drive spins but the system thinks there's no disk there.

Edit: Just read Tez's post. I've tried the boot with several boot disks. Can boot maybe one out of twenty attempts, using various boot disks, after a power cycle on/off.
 
NutmegCT said:
"Do you know how to ohm-out cables for proper connections?"

Just guessing again, but doesn't that mean to check for continuity? (I've actually done that for the power cable, both the single-jack and the double-jack cable. All tests for proper continuity.)

Or does that mean something on a higher level, like checking the resistance between specific pins for specific ohm readings?
Click to expand...

No, that's what I meant. Did you inspect the pins for corroded, bent or broken pins? Both on the harness and on the system board?
 
"Did you inspect the pins for corroded, bent or broken pins? Both on the harness and on the system board?"

Yep - did that early on. Really very clean and dust-free inside. All pins shiny.

I agree that it could be an almost-invisible crack or solder joint problem on the system board. But as everything so far has been "random and intermitten" it's frustrating.

Going to let it cool power off for another 30 minutes, then try the boot process again.

T.
 
OK - one step at a time.

Even tho' I have double-density drives, I just tried booting from a single density system disk. The original Osborne system disk.

System loaded cp/m and help perfectly. I hit ESC to leave the help system and got the A> prompt. I then did a dir of the single density disk in B. Again, read perfectly.

I repeated the whole process above, with no problems.

It's beginning to seem that my system has trouble with booting and/or reading double-density disks.

Yep - just powered off and did the whole thing again. No problems with booting and reading SD disks. Even tho' I've got the 1.4 ROM (which supports DD), DD drives, and the optional DD card installed.

Any thoughts? Should I just be happy with the SD system as is? (even tho' all my disks but four are DD ...)

Progress!
T.
 
NutmegCT said:
OK - one step at a time.

Even tho' I have double-density drives, I just tried booting from a single density system disk. The original Osborne system disk.

System loaded cp/m and help perfectly. I hit ESC to leave the help system and got the A> prompt. I then did a dir of the single density disk in B. Again, read perfectly.

I repeated the whole process above, with no problems.

It's beginning to seem that my system has trouble with booting and/or reading double-density disks.

Yep - just powered off and did the whole thing again. No problems with booting and reading SD disks. Even tho' I've got the 1.4 ROM (which supports DD), DD drives, and the optional DD card installed.

Any thoughts? Should I just be happy with the SD system as is? (even tho' all my disks but four are DD ...)

Progress!
T.
Click to expand...

Tom, are you sure the DD system disks you have are not now corrupted from all the random disk activity during a crash?

Tez
 
"Tom, are you sure the DD system disks you have are not now corrupted from all the random disk activity during a crash?"

Hi Tez. Recently I haven't been too sure of anything! Per the OCC user guide, if I boot using a SD system disk, the system thinks it's a SD system and can only read/write SD disks. If I boot using a DD system disk, the system should read/write SD and DD disks.

Just so I don't jump to conclusions ... how could I check to see if a disk is DD or SD? I took what I think is a DD system disk, one of the ones I can't boot from, and can't successfully read it after booting using a SD system disk. But honestly, I don't know how to tell a SD from a DD disk just by looking at them. They all seem to have the upper and lower "read/write" windows, and the write protect notch.

I just this minute tried booting from an original Osborne DD system disk; the label says "double density". BOOT ERROR. I then booted from an original Osborne SD system disk. Booted fine, but won't read that same DD system disk in the other drive. BDos error.

Edit: it would be very helpful if I could find the actual instructions for adding the DD board. I've got the proper 1.4 ROM, the DD board, the DD [Edit: DD board] to main board cable, and the DD drives [Edit: and cable set] from my old computer. But I wonder if there's some jumper that needed changing. The DD Drive Manual only tells how to use the DD system - not how to install it.
 
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GENTLEMEN!

Reading Dave's last post I got to thinking. I went upstairs and rummaged around, and found one of my old original Osborne DD system disks. [Edit: I haven't used that disk for over 20 years.] It actually says DD on the label. Brought it down, slipped it in the A drive - and it booted!

However, system won't boot from that same DD disk if booted from the B drive. BDos error.

Interestingly, if I boot from the DD system disk in A, I *can* read a DD disk in B. Just did an xdir on another DD disk and see it holding 185K - so it is obviously a DD disk.

Looks like the DD drives are working - on *most* of the disks, but not able to boot DD system from the B drive.

T.
 
Tom,
Did the flashing screen and squeals suddenly go away? Is your system still all buttoned up? If so, it is possible for things like that to return, but so far so good.

If it returns, it may be better to leave power off until you plan a next step as recycling power under those conditons is hard on a power supply.
 
NutmegCT said:
Edit: it would be very helpful if I could find the actual instructions for adding the DD board. I've got the proper 1.4 ROM, the DD board, the DD [Edit: DD board] to main board cable, and the DD drives [Edit: and cable set] from my old computer. But I wonder if there's some jumper that needed changing. The DD Drive Manual only tells how to use the DD system - not how to install it.
Click to expand...

I've been watching this one just for fun, and was starting to wonder about the DD upgrade.

I have the manual:
"The Double Density Upgrade for the Osborne One Computer - Installation & Operating Instructions" (has photos too!). It was from Nuevo Electronics Corporation, Richmind, TX.
I also have a manual for "The OZROM 1E - A Replacement ROM for the Osborne 1 Computer" from Micro management, Inc.

I'm running out for a haircut, but will scan the docs when I get back.
PM me your email address, and I'll email them to you later.
 
NutmegCT said:
GENTLEMEN!

Reading Dave's last post I got to thinking. I went upstairs and rummaged around, and found one of my old original Osborne DD system disks. [Edit: I haven't used that disk for over 20 years.] It actually says DD on the label. Brought it down, slipped it in the A drive - and it booted!

However, system won't boot from that same DD disk if booted from the B drive. BDos error.

Interestingly, if I boot from the DD system disk in A, I *can* read a DD disk in B. Just did an xdir on another DD disk and see it holding 185K - so it is obviously a DD disk.

Looks like the DD drives are working - on *most* of the disks, but not able to boot DD system from the B drive.

T.
Click to expand...

Tom,

It could be that that original DD disk is corrupted then. If you only have ONE DD boot disk left I'd be very careful. With a non-working B drive, I guess you can't make a copy? Are you able to use a Dave Dunfield disk image and make one on a PC? As I said, in my repair jobs with the Obsorne where the system would crash and burn, the crashing would sometimes corrupt whatever disk was in the boot drive.

As to the B drive problem, I had a similar thing with my Kaypro (you can read about it here). Could be dirty heads, incorrect speed, mis-aligniment or some problem with the disk clamp.

Tez
 
Dave - yes, all those weirdnesses have disappeared. I'd been running it power on for over an hour. Never had a single problem with any SD disks; even booted with the newly found DD system disk.

However, while in DD mode, I changed B disks and did a CTRL-C to notify the system that the disk was changed. As per usual, the A drive spun, but could not read the A disk (the DD disk I booted from).

Then I tried a reset, and it *still* couldn't boot from that DD system disk. It does however still work fine booting from either A or B with a SD system disk.

Lorne - thanks very much for the offer. I'll PM you my email.

Tom
 
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