20 Mar
2014
20 Mar
'14
1:58 p.m.
Hi folks!
I grabbed my first Osborne I today :)
I powered it and it showed a crisp and vivid monitor :D
I had a bunch of disks, but none of them worked (boot error).
So I tried them elsewhere: they were all Double Density (so I have DD
drives) but almost unreadable: the surface is dirty and covered with
spots, may be fungi :(
I dowloaded some IMD images and gave it a try...
It booted with the Osborne logo and then the screen was slowly filled
with junk, mainly "@". The Osborne stopped responding: I pressed the
Reset button...
Continuous beep on reboot, screen filled with random chars.
I powered off, waited some minutes: no changes, no boot.
Beep and screen junk, the floppy drives lights dance rhythmically :p
I'll able to open it only the next week (the work table is full), but
I'd like to figure out what's happened.
Ram? Rom?
Thanks!
20 Mar
20 Mar
2:11 p.m.
On Thu, 20 Mar 2014, supervinx wrote:
Continuous beep on reboot, screen filled with random
chars.
I powered off, waited some minutes: no changes, no boot.
Beep and screen junk, the floppy drives lights dance rhythmically :p
I'll able to open it only the next week (the work table is full), but
I'd like to figure out what's happened.
My O1 had a sandwiched pair of boards inside that plugged together with
dip pins and headers. All of them were oxidized. I pulled off and
reseated the daughterboard and reseated all chips and any other connectors
I could get to. That did the trick.
If the unit has been in storage in a humid area, you may want to open up
the drives and give them a good cleaning.
Steve
--
3:23 p.m.
check the powersupply capacitors, and all othe capacitors. they can
short or have taken a completely wong value over the years. changing
them all is a good idea.
On 20-03-14 21:58, supervinx wrote:
Hi folks!
I grabbed my first Osborne I today :)
I powered it and it showed a crisp and vivid monitor :D
I had a bunch of disks, but none of them worked (boot error).
So I tried them elsewhere: they were all Double Density (so I have DD
drives) but almost unreadable: the surface is dirty and covered with
spots, may be fungi :(
I dowloaded some IMD images and gave it a try...
It booted with the Osborne logo and then the screen was slowly filled
with junk, mainly "@". The Osborne stopped responding: I pressed the
Reset button...
Continuous beep on reboot, screen filled with random chars.
I powered off, waited some minutes: no changes, no boot.
Beep and screen junk, the floppy drives lights dance rhythmically :p
I'll able to open it only the next week (the work table is full), but
I'd like to figure out what's happened.
Ram? Rom?
Thanks!
--
Met vriendelijke Groet,
Simon Claessen
drukknop.nl
21 Mar
21 Mar
2:11 p.m.
check the powersupply capacitors, and all othe capacitors. they can
short or have taken a completely wong value over the years. changing
them all is a good idea.
can somebody please expalin why I rarely see capacitor failure, for all I
work on machines a lot older than this Osborne?
More seriously, I ahve had capacitors fail, but not that many. I have
never had to re-cap an entire machine.
In this case I would, indeed, start by checkig nthe power supply outputs
-- votlage and ripple. If there is a problem, then I would find out what
it is. It might wwell be a capacitor, but I wouldn't change it until I
knew. It might also be a bad connection oxidised pins, etc), a failed IC
(bit-rot in an EPROM, RAM failur, etc). Or a dozen other htings.
My 'first rule of repair' is not to change anything until you know what
the problem is....
-tony
3:19 p.m.
On Mar 21, 2014 3:48 PM, "Tony Duell" <ard at p850ug1.demon.co.uk> wrote:
can somebody please expalin why I rarely see capacitor
failure, for all I
work on machines a lot older than this Osborne?
It depends a lot on the manufacture of the capacitors, and seemingly not
necessarily in ways that strongly correlate with other specific measures of
"quality". I definitely don't understand it. I would expect the rate of
oxide layer breakdown for non-use to be consistent across all aluminum
electrolytic capacitors, but it isn't. My best guess is that the
electrolyte chemistry somehow stabilizes the oxide. Perhaps they use
additives with that specific purpose. Certainly the electrolyte formulation
varies considerably, and often is a trade secret.
After a decade of non-use, some (but not all) of the 40-year-old capacitors
in the PDP-1 had to be reformed, and a few of those could not be reformed.
It is entirely possible that capacitors made more recently may have a
slower rate of non-use oxide breakdown.
Eric
22 Mar
22 Mar
1:45 p.m.
On Mar 21, 2014 3:48 PM, "Tony Duell" <ard at p850ug1.demon.co.uk>
wrote:
It's not even that conssitent between capacoitors of the same nominal age
and manufacture. I am sure many of us have had one original capacitor in
a device fail (oxide disoiving -> short circuit) while the others, same
manufacturr, go on for many more years.
can somebody please expalin why I rarely see
capacitor failure, for all I
work on machines a lot older than this Osborne?
It depends a lot on the manufacture of the capacitors, and seemingly not
necessarily in ways that strongly correlate with other specific measures of
"quality". I definitely don't understand it. I would expect the rate of
oxide layer breakdown for non-use to be consistent across all aluminum
electrolytic capacitors, but it isn't. My best guess is that the
electrolyte chemistry somehow stabilizes the oxide. Perhaps they use
additives with that specific purpose. Certainly the electrolyte formulation
varies considerably, and often is a trade secret.
After a decade of non-use, some (but not all) of the 40-year-old capacitors
in the PDP-1 had to be reformed, and a few of those could not be reformed.
It is entirely possible that capacitors made more recently may have a
slower rate of non-use oxide breakdown.
The cynic in me would suggest that the more modern ones are more likely
to fail :-)
More seriosuly, of course I have had electrolytic capacitors fail. But
I've certainly not had to repalce all the ones in all my classic
ocmptuers -- in fact many machines, 40+ years old, are still runnign with
all their original capacitors.
When a machine stops working, IMHO, you should not blindly re-cap it.
Suppose it still doesn';t work after you've done this. What do you then
conclude? That the original fault is still there, it wasn't a bad
capacitor? That one of the replacement capacitors was faulty? That you
made a mistake fitting them?
If you have a fualt, like nist spikes on a power line, that could be due
to a faulty capcitor, then of course you _check_ the capacitors. And
replace (or reform) them if necessary. Capacitors can fail. But changing
parts for no logical reason will get you nowhere fast.
-tony
6:58 p.m.
On Sat, Mar 22, 2014 at 2:45 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
If you have a fualt, like nist spikes on a power line,
that could be due
to a faulty capcitor, then of course you _check_ the capacitors. And
replace (or reform) them if necessary. Capacitors can fail. But changing
parts for no logical reason will get you nowhere fast.
If old electrolytics fail for want of reformation, you'll know about it.
The failure mode is punch-through; a portion of the capacitor becomes a
dead short, though usually only briefly, and it can be spectacular. (At
least that's what I've observed for large ones with 16V and 25V ratings;
smaller, lower-voltage ones might not be obvious.)
With the PDP-1, we had the expectation that some capacitors would need
reformation. If we hadn't checked them, and reformed the ones that needed
it, some of them would have blown up and needed modern replacement. The
purpose of our checking and reformation was to avoid replacing any more
than absolutely necessary, due to the interest in preserving as much of the
historical artifact as possible.
We had to replace one high-voltage capacitor (which was not electrolytic),
and we were able to get an identical NOS capacitor from the original
manufacturer, even though it was custom-made for DEC and probably hadn't
been sold to them for more than 20 years.
Eric
23 Mar
23 Mar
12:40 p.m.
On Sat, Mar 22, 2014 at 2:45 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
Absolutely.
If you have a fualt, like nist spikes on a power
line, that could be due
to a faulty capcitor, then of course you _check_ the capacitors. And
replace (or reform) them if necessary. Capacitors can fail. But changing
parts for no logical reason will get you nowhere fast.
If old electrolytics fail for want of reformation, you'll know about it. The failure mode is punch-through; a portion of the
capacitor becomes a
dead short, though usually only briefly, and it can be spectacular. (At
Yes. Contrary to popular belief, the electrolyte is not the dielectric
(insulator) in the capacitor. It can't be, an electrolyte is a conductor.
In fact the electrolyte is the -ve 'plate', the dielectric is the oxide
film on the positive electrode. So when that oxide re-disolves, the
capacitor goes dead short.
If you are lucky, it'll blow a fuse. If you are less luccky, it will blow
the rctifier feeding it and then blow the fuse. If you are even more
unlucky, the transformer will protect the fuse by failiung furst. And if
you are very unlucky, nothign will fail. But the capcitor will pass an
excessive current, the electrolyte will boil amd it will explode. Many
large capcitors ahve a safety vent which is supposed to prevent this, but...
least that's what I've observed for large ones
with 16V and 25V ratings;
smaller, lower-voltage ones might not be obvious.)
With the PDP-1, we had the expectation that some capacitors would need
reformation. If we hadn't checked them, and reformed the ones that needed
it, some of them would have blown up and needed modern replacement. The
purpose of our checking and reformation was to avoid replacing any more
than absolutely necessary, due to the interest in preserving as much of the
historical artifact as possible.
Sure. Nobody, least of all me, is suggestign that chcecking things before
applying power is a bad idea. In fact I wil lgo the otehr way and say it
is very foolish to apply power to a classic computer before doign a
number of 'cold tests', which incldue checking for shorts on every supply
line (regualted and unregualted), which should pick up shorted smoothing
capcitors, 'meggering' the transformer, and so on. You may also want to
test the capcitors on a current-limited bench supply of a suitable
voltage.
No, what I am commenting on is the idea that when a machien fails, it is
a necessary to re-cap it. No matter what the symptoms are, and without
doing any tests to find if the fault could possibly be a failed capacitor.
-tony
5:13 a.m.
of course not. doing things in life without thinking is generally a bad
idea (or the absence of one. :-) ) we have idiots addicted to
brainsharing too much already. look at the highways for example
On 22-03-14 21:45, Tony Duell wrote:
--
Met vriendelijke Groet,
Simon Claessen
drukknop.nl
On Mar 21, 2014 3:48 PM, "Tony Duell" <ard at p850ug1.demon.co.uk>
wrote:
It's not even that conssitent between capacoitors of the same nominal age
and manufacture. I am sure many of us have had one original capacitor in
a device fail (oxide disoiving -> short circuit) while the others, same
manufacturr, go on for many more years.
can somebody please expalin why I rarely see
capacitor failure, for all I
work on machines a lot older than this Osborne?
It depends a lot on the manufacture of the capacitors, and seemingly not
necessarily in ways that strongly correlate with other specific measures of
"quality". I definitely don't understand it. I would expect the rate of
oxide layer breakdown for non-use to be consistent across all aluminum
electrolytic capacitors, but it isn't. My best guess is that the
electrolyte chemistry somehow stabilizes the oxide. Perhaps they use
additives with that specific purpose. Certainly the electrolyte formulation
varies considerably, and often is a trade secret.
After a decade of non-use, some (but not all) of the 40-year-old capacitors
in the PDP-1 had to be reformed, and a few of those could not be reformed.
It is entirely possible that capacitors made more recently may have a
slower rate of non-use oxide breakdown.
The cynic in me would suggest that the more modern ones are more likely
to fail :-)
More seriosuly, of course I have had electrolytic capacitors fail. But
I've certainly not had to repalce all the ones in all my classic
ocmptuers -- in fact many machines, 40+ years old, are still runnign with
all their original capacitors.
When a machine stops working, IMHO, you should not blindly re-cap it.
Suppose it still doesn';t work after you've done this. What do you then
conclude? That the original fault is still there, it wasn't a bad
capacitor? That one of the replacement capacitors was faulty? That you
made a mistake fitting them?
If you have a fualt, like nist spikes on a power line, that could be due
to a faulty capcitor, then of course you _check_ the capacitors. And
replace (or reform) them if necessary. Capacitors can fail. But changing
parts for no logical reason will get you nowhere fast.
-tony
21 Mar
21 Mar
5:18 p.m.
It really depends on the age, but absolutely not lineair.I have a
fernseh video monitor from around 1955 still working fawlessly without
any work on it done. but machiens from around 1991 and up are
dramatically bad. als som areas round 1978-1980 are suspect. i have old
macintoshes from 1989 in perfect condition, but all of the ones made
after 1991 with leakage and shorts. really all. mac II no problem, Mac
IIfx all bad. that is what i mean.
On 21-03-14 22:11, Tony Duell wrote:
--
Met vriendelijke Groet,
Simon Claessen
drukknop.nl
check the powersupply capacitors, and all othe capacitors. they can
short or have taken a completely wong value over the years. changing
them all is a good idea.
can somebody please expalin why I rarely see capacitor failure, for all I
work on machines a lot older than this Osborne?
More seriously, I ahve had capacitors fail, but not that many. I have
never had to re-cap an entire machine.
In this case I would, indeed, start by checkig nthe power supply outputs
-- votlage and ripple. If there is a problem, then I would find out what
it is. It might wwell be a capacitor, but I wouldn't change it until I
knew. It might also be a bad connection oxidised pins, etc), a failed IC
(bit-rot in an EPROM, RAM failur, etc). Or a dozen other htings.
My 'first rule of repair' is not to change anything until you know what
the problem is....
-tony
8:46 p.m.
On Fri, Mar 21, 2014 at 6:18 PM, Simon Claessen <simski at dds.nl> wrote:
It really depends on the age, but absolutely not
lineair.I have a fernseh
video monitor from around 1955 still working fawlessly without any work on
it done. but machiens from around 1991 and up are
The *rate* at which the oxide breakdown occurs might have some correlation
with age due to improvements in the construction, but the breakdown process
has nothing to do with the absolute age of the capacitor and everything to
do with how long the capacitor sits unused. A 40 year old aluminum
electrolytic that is regularly used should have no oxide breakdown, while a
20 year old capacitor that has never been used can have serious breakdown
and need reforming.
The oxide breakdown process is also essentially unrelated to the drying out
of electrolyte, which is caused by defective seals or overstress.
5:19 p.m.
CAD and bean counters. Using the latest CAD programs and simulations people
can design machines on the edge of properly working with little fudge
factor, then the bean counters trim some more parts away to save a few
pennies. You seen many newer motherboards with spaces for capacitors that
were never installed to save a buck. Back when machines were many thousands
of dollars and expected to work a long time designers were much more careful
in design. You also have the higher heat of operating systems.
-----Original Message-----
From: Tony Duell
Sent: Friday, March 21, 2014 5:11 PM
To: cctalk at classiccmp.org
Subject: Re: Osborne 1 blues...
check the powersupply capacitors, and all othe capacitors. they can
short or have taken a completely wong value over the years. changing
them all is a good idea.
can somebody please expalin why I rarely see capacitor failure, for all I
work on machines a lot older than this Osborne?
---
This email is free from viruses and malware because avast! Antivirus protection is
active.
http://www.avast.com
6:04 p.m.
On 3/21/2014 5:19 PM, TeoZ wrote:
CAD and bean counters. Using the latest CAD programs
and simulations
people can design machines on the edge of properly working with little
fudge factor, then the bean counters trim some more parts away to save
a few pennies. You seen many newer motherboards with spaces for
capacitors that were never installed to save a buck. Back when
machines were many thousands of dollars and expected to work a long
time designers were much more careful in design. You also have the
higher heat of operating systems.
Older systems were designed, and at times it
wasn't bean counters, but
engineers with wire clippers who attacked them.
Earl Muntz is a classic example. He made three total restarts until he
got a TV chassis that was as cheap as he wanted and the most of the
techniques were just leaving out parts and seeing how well it worked.
He also did do another thing which was to eliminate channel tuner parts
for markets which were large and just put in the channels that he knew
had the most viewers. But it was not very scientific.
One of my EE professors had some stories about things shorting out and
the design still working and giving direction to what to eliminate or
change.
jim
8:47 p.m.
On Fri, Mar 21, 2014 at 7:04 PM, jim s <jws at jwsss.com> wrote:
Older systems were designed, and at times it
wasn't bean counters, but
engineers with wire clippers who attacked them.
Earl Muntz is a classic example. He made three total restarts until he
got a TV chassis that was as cheap as he wanted and the most of the
techniques were just leaving out parts and seeing how well it worked.
Call Muntz an engineer if you want, but that technique was bean-counting,
not engineering.
22 Mar
22 Mar
12:12 a.m.
On 3/21/2014 8:47 PM, Eric Smith wrote:
On Fri, Mar 21, 2014 at 7:04 PM, jim s <jws at
jwsss.com> wrote:
I met him. He was the one who called the shots and had others
doing the
building of the sets. He was a salesman and marketeer. The thing he
was good at was just spotting things people didn't know the value of and
exploiting it.
The last items he was selling was the remains of a horribly executed
entry by Technicolor into the video industry. He had bought all the
small 8mm sized custom recorders they had and was selling them for $99
bucks when the average mini VHS was selling for about 1000 with a camera.
Technicolor tried to get a couple thousand for them and maybe sold 2.
they bankrupted on that and the final demise of the demand for their
services business.
They are still a junkyard IP dog, but only as a patent troll now days.
The recorders that Muntz sold wholesale were also sold at most of the
computer stores around the LA area. Everyone in the junk biz bought some.
The wonderful cycles of junk at the swap meets. So many gizmos were
sold at the stores that were failures for their companies, but a boon
for the scrappers here. That's a subject for another thread.
Older systems were designed, and at times it
wasn't bean counters, but
engineers with wire clippers who attacked them.
Earl Muntz is a classic example. He made three total restarts until he
got a TV chassis that was as cheap as he wanted and the most of the
techniques were just leaving out parts and seeing how well it worked.
Call Muntz an engineer if you want, but that technique was bean-counting,
not engineering. 
21 Mar
21 Mar
7:48 p.m.
On 03/21/2014 05:19 PM, TeoZ wrote:
can somebody please expalin why I rarely see capacitor
failure, for all I
work on machines a lot older than this Osborne?
I can offer one good explanation--switching power supplies. The high
frequency AC ripple was really murder on capacitors of the day.
I've got much older linear supplies as well, and they're mostly fine.
--Chuck
20 Mar
20 Mar
3:27 p.m.
I powered it and it showed a crisp and vivid monitor
:D
I had a bunch of disks, but none of them worked (boot error).
So I tried them elsewhere: they were all Double Density (so I have DD
drives) but almost unreadable: the surface is dirty and covered with
spots, may be fungi :(
Original O1 machines were SD, not DD. Sounds like you're convinced
these diskettes belong with the machine, though.
Sounds like you now need to clean the heads of all drives through which
those diskettes passed, though. And hope there's nothing on them that
you need to salvage, since they're now scuffed up.
De
3:53 p.m.
Il giorno gio, 20/03/2014 alle 18.27 -0400, Dennis Boone ha scritto:
Well, there were original Osborne disks, labeled "Osborne 1"
And it booted from a double density IMD create disk...
This is why I'm convinced my Osborne 1 belongs to the last production,
with DD drives...
I powered it
and it showed a crisp and vivid monitor :D
I had a bunch of disks, but none of them worked (boot error).
So I tried them elsewhere: they were all Double Density (so I have DD
drives) but almost unreadable: the surface is dirty and covered with
spots, may be fungi :(
Original O1 machines were SD, not DD. Sounds like you're convinced
these diskettes belong with the machine, though.
5:40 p.m.
Those spots certainly will be fungi. I wouldn't use those disks in any
drive, although you could try washing them as a last resort if you really
needed to extract some files.
Your problems with the Osborne sound very similar to the ones I had with my
first machine. These are memory mapped devices so any junk going through
RAM is going to trigger all sorts of unpredictable behaviour. My problem
was a faulty 4116 chip. See 1/2 way down my blog article at:
http://www.classic-computers.org.nz/blog/2008-12-06-osborne-repair-1.htm
Terry (Tez)
On Fri, Mar 21, 2014 at 11:53 AM, supervinx <supervinx at libero.it> wrote:
Il giorno gio, 20/03/2014 alle 18.27 -0400, Dennis
Boone ha scritto:
Well, there were original Osborne disks, labeled "Osborne 1"
And it booted from a double density IMD create disk...
This is why I'm convinced my Osborne 1 belongs to the last production,
with DD drives...
I powered
it and it showed a crisp and vivid monitor :D
I had a bunch of disks, but none of them worked (boot error).
So I tried them elsewhere: they were all Double Density (so I have DD
drives) but almost unreadable: the surface is dirty and covered with
spots, may be fungi :(
Original O1 machines were SD, not DD. Sounds like you're convinced
these diskettes belong with the machine, though.
6:03 p.m.
FWIW, I recently came into possession of 50+ 5-1/4" floppies, mostly in
Atari format, some in Commodore. Almost all had odd spots of haze on the
media, and smelled characteristically of mildew.
None were readable / bootable. Pretty sad, I had to trash a load of vintage
docs & books as well, some schlub had left them to sit in the damp for who
knows how long...
Does that +ever+ turn out well? For anything that can corrode or otherwise
suffer mildew?
On Thu, Mar 20, 2014 at 7:40 PM, Terry Stewart <terry at webweavers.co.nz>wrote:
Those spots certainly will be fungi. I wouldn't
use those disks in any
drive, although you could try washing them as a last resort if you really
needed to extract some files.
Your problems with the Osborne sound very similar to the ones I had with my
first machine. These are memory mapped devices so any junk going through
RAM is going to trigger all sorts of unpredictable behaviour. My problem
was a faulty 4116 chip. See 1/2 way down my blog article at:
http://www.classic-computers.org.nz/blog/2008-12-06-osborne-repair-1.htm
Terry (Tez)
On Fri, Mar 21, 2014 at 11:53 AM, supervinx <supervinx at libero.it> wrote:
Well, there were original Osborne disks, labeled "Osborne 1"
And it booted from a double density IMD create disk...
This is why I'm convinced my Osborne 1 belongs to the last production,
with DD drives...
Il giorno gio, 20/03/2014 alle 18.27 -0400,
Dennis Boone ha scritto:
> > I powered it and it showed a crisp and vivid monitor :D
> > I had a bunch of disks, but none of them worked (boot error).
> > So I tried them elsewhere: they were all Double Density (so I have
DD
drives) but almost unreadable: the surface is dirty
and covered with
spots, may be fungi :(
Original O1 machines were SD, not DD. Sounds like you're convinced
these diskettes belong with the machine, though.
21 Mar
21 Mar
4:57 a.m.
On Thu, 20 Mar 2014, drlegendre . wrote:
FWIW, I recently came into possession of 50+
5-1/4" floppies, mostly in
Atari format, some in Commodore. Almost all had odd spots of haze on the
media, and smelled characteristically of mildew.
None were readable / bootable. Pretty sad, I had to trash a load of vintage
docs & books as well, some schlub had left them to sit in the damp for who
knows how long...
Does that +ever+ turn out well? For anything that can corrode or otherwise
suffer mildew?
Depends on your definition of "well". In terms of recordable media I have
about 90% success rate for data recovery using the following procedure:
- Slit open the diskette jacket on the edge opposite the cutouts and
remove the media. If there's no hub ring, make a tiny spot with indelible
marker right against the center hole to denote "top".
- Wash gently by hand using mild, non-scented soap and warm water, then
rinse in warm water.
- Inspect it under bright lighting and repeat if you missed any spots.
- Blot dry with paper towels - if you are in a hurry just wave it around a
bit to evaporate any drops of water that are left.
- Sacrifice a clean, new diskette by removing the media and replacing with
the one you're trying to recover.
- Give it a try on a drive with clean heads.
I've been able to return a fair number of things from the bit-bucket in
this manner. Obviously it won't help you in cases where the binder is
breaking down...
Archivists recover water and mold damaged print media all the time, but
it's not something I've ever pursued.
Steve
--
22 Mar
22 Mar
6:51 a.m.
----------------------------------------
From: snhirsch at gmail.com
On Thu, 20 Mar 2014, drlegendre . wrote:
I've had disk where the adhesive for the liner of the
envelope had bled through to the disk, making spots on the disk.
I used rubbing alcohol to remove the goo with good results.
I'd set the disk on a flat surface and use swabs. Little
of the media came off, only the goo.
Dwight
FWIW, I recently came into possession of 50+
5-1/4" floppies, mostly in
Atari format, some in Commodore. Almost all had odd spots of haze on the
media, and smelled characteristically of mildew.
None were readable / bootable. Pretty sad, I had to trash a load of vintage
docs & books as well, some schlub had left them to sit in the damp for who
knows how long...
Does that +ever+ turn out well? For anything that can corrode or otherwise
suffer mildew?
Depends on your definition of "well". In terms of recordable media I have
about 90% success rate for data recovery using the following procedure:
- Slit open the diskette jacket on the edge opposite the cutouts and
remove the media. If there's no hub ring, make a tiny spot with indelible
marker right against the center hole to denote "top".
- Wash gently by hand using mild, non-scented soap and warm water, then
rinse in warm water.
- Inspect it under bright lighting and repeat if you missed any spots.
- Blot dry with paper towels - if you are in a hurry just wave it around a
bit to evaporate any drops of water that are left.
- Sacrifice a clean, new diskette by removing the media and replacing with
the one you're trying to recover.
- Give it a try on a drive with clean heads.
I've been able to return a fair number of things from the bit-bucket in
this manner. Obviously it won't help you in cases where the binder is
breaking down...
Archivists recover water and mold damaged print media all the time, but
it's not something I've ever pursued.
Steve
9:35 a.m.
On 03/22/2014 06:51 AM, dwight wrote:
----------------------------------------
I've had disk where the adhesive for the liner of
the
envelope had bled through to the disk, making spots on the disk.
I used rubbing alcohol to remove the goo with good results.
I'd set the disk on a flat surface and use swabs. Little
of the media came off, only the goo.
I'll repeat what I said before--if the binder is compromised (you'll
know it by the "squeal" when you try to read one of these things--that's
the sound of the oxide peeling off and fouling things), bake the naked
cookies at 130 F for about a day. Often that will get you a read or two
before the diskette self-destructs.
I've even done this to get a good read out of old Wabash floppies.
--Chuck
12:06 p.m.
I also suspect a ram chip...
Since I can't open it by now, I'm gathering info for a sure shot
repair...
After a long rest, the O1 seems to boot normally, and suddenly, at warm
up, the garbage collecting starts again...
I've a stock of 4116, so it shouldn't be a problem...
In my rather limited experience I've found that problems which manifest
themselves on warming up tend to be capacitors rather than ICs. These can
be hard to track down. They are not Osborne 1 related, but here are a
couple of links showing my experience with dodgy caps. In both cases the
machines worked ok until warmed up.
http://www.classic-computers.org.nz/blog/2009-03-29-re-repairing-an-apple-I…
http://www.classic-computers.org.nz/blog/2014-02-22-ti99_4a-reconstituting.…
Terry (Tez)
21 Mar
21 Mar
5:02 a.m.
I also suspect a ram chip...
Since I can't open it by now, I'm gathering info for a sure shot
repair...
After a long rest, the O1 seems to boot normally, and suddenly, at warm
up, the garbage collecting starts again...
I've a stock of 4116, so it shouldn't be a problem...
I'll keep you posted...
22 Mar
22 Mar
9:09 a.m.
A lot of time if a system works until warms up its due to bad contacts or wiring. Oxidized
connections or cold solder joints would be something to look for.
Sent from my iPhone /////c
On Mar 21, 2014, at 7:02 AM, supervinx <supervinx
at libero.it> wrote:
I also suspect a ram chip...
Since I can't open it by now, I'm gathering info for a sure shot
repair...
After a long rest, the O1 seems to boot normally, and suddenly, at warm
up, the garbage collecting starts again...
I've a stock of 4116, so it shouldn't be a problem...
I'll keep you posted...
3710
days inactive
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25 comments
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participants (13)
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ard＠p850ug1.demon.co.uk -
barythrin＠gmail.com -
cclist＠sydex.com -
dkelvey＠hotmail.com -
drb＠msu.edu -
drlegendre＠gmail.com -
jws＠jwsss.com -
simski＠dds.nl -
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supervinx＠libero.it -
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