11 Sep
2010
11 Sep
'10
4:18 p.m.
I thought a video might be easier for you all to see the issue I am
having with restoring my Xerox Alto.
The issue I am having is the Diablo Disk drive does not power on fully
(I am measuring +15 and -15V on the drive, but +5V is only measuring at
around 2.5V. The lamps on the front of the drive do not light-up, and
the LOAD/RUN button does nothing, hence the door lock does not unlock.
Here is a link to the video: http://www.youtube.com/watch?v=mx80CvjuvyE
I have visually inspected all PCB boards and components, nothing seem to
be damaged. Also, the power supplies seem to be outputting power
properly (as seen via the RED voltage LEDS in the Alto card cage.
Any recommendations on how to troubleshoot the disk drive further?
12 Sep
12 Sep
5 p.m.
Given what you're seeing with the 5v rail, my advice would be to first isolate the 5v
supply and troubleshoot it. Either it is defective or it is trying to deliver into a
significant sink. Chances are it is defective.
I don't know for sure but given the era of this drive I'd suspect the power supply
is a switcher. Run it into a lightbulb to provide a load. If you aren't getting 5v
into a dummy load, consider changing out the filter caps - on a machine of this era,
they're almost certainly bad unless they've been replaced along the way (look at
the date codes). Of course, there's also the possibility of a bad pass regulator or
other active component, but my experience has been that it's most often the filter
caps that go south.
None of this advice is really much different for a linear supply - if you have a big
ol' transformer in the box - but you don't have to have a load just to get it to
run. A load is still a good idea so you can see if the filter caps collapse when the
power supply is actually trying to supply current.
If you find you have a perfectly good 5v into a dummy (and look at it with a scope, too),
then I'd first look at filter caps on the boards fed by the 5v. I had a power supply
in a Nova 1200 that was actually working just fine but was trying to deliver 15v into a
dead short caused by a filter cap on one of the core memory rails. The current limiter in
the power supply worked admirably, but it looked like the 15v supply was not generating,
until I isolated it with a dummy load....
It looks like a really nice machine! Congratulations on a fabulous acquisition -- Ian
________________________________________
From: cctalk-bounces at classiccmp.org [cctalk-bounces at classiccmp.org] On Behalf Of
Nick Allen [nick.allen at comcast.net]
Sent: Saturday, September 11, 2010 4:18 PM
To: cctech at classiccmp.org
Subject: Help resurrect my Xerox Alto
I thought a video might be easier for you all to see the issue I am
having with restoring my Xerox Alto.
The issue I am having is the Diablo Disk drive does not power on fully
(I am measuring +15 and -15V on the drive, but +5V is only measuring at
around 2.5V. The lamps on the front of the drive do not light-up, and
the LOAD/RUN button does nothing, hence the door lock does not unlock.
Here is a link to the video: http://www.youtube.com/watch?v=mx80CvjuvyE
I have visually inspected all PCB boards and components, nothing seem to
be damaged. Also, the power supplies seem to be outputting power
properly (as seen via the RED voltage LEDS in the Alto card cage.
Any recommendations on how to troubleshoot the disk drive further?
7:19 p.m.
On 9/12/10 5:00 PM, Ian King wrote:
Given what you're seeing with the 5v rail, my
advice would be to first isolate the 5v supply and troubleshoot it.
Most of the Mighty Mite 5v supplies have failed. They weren't all that great to begin
with.
I'd be curious if you're able to get a schematic out of LH for it. I have about 10
dead ones.
I've built bolt-in replacement frames using modern Lambda multi-voltage switchers. You
need +/- 5
to replace the Mighty Mite.
13 Sep
13 Sep
2:11 p.m.
New subject: Help resurrect my Xerox Altou
On 9/12/10 5:00 PM, Ian King wrote:
> Given what you're seeing with the 5v rail, my advice would be to
> first isolate the 5v supply and troubleshoot it.
I htought the OP implied the system power rails were correct, it was the
iternal 5V rail for the disk drive that was low.
Most of the Mighty Mite 5v supplies have failed. They
weren't all that
great to begin with.
I'd be curious if you're able to get a schematic out of LH for it. I
have about 10 dead ones.
Unless there's something _very_ strange about these supplies it whould be
possiuble to reverse engineer them and troubleshoot them without an
official schematic. Hekc, a lot of faults can probably be found without a
schematic at all.
-tony
19 Sep
19 Sep
7:20 a.m.
Some GOOD news, at the Midwest VCF, Chris (from St Paul, don't
remember last name) and Eric Kudzin were huge helps and took Jim S's
recommendation and repaired the 5V Op Amp fixing the 5V issue and now
the Disk Drive SPINS! We still need to repair the CRT and diagnose the
rest of the system, but we are making progress!!
Thank you Jim (for the amazing feat of properly diagnosing remotely via
schematics) and thank you Chris and Eric for your endless hours of help
at the VCF!'
I will keep everyone posted as we progress, Eric and I will be working
over the next several months to restore the Alto!
4:09 p.m.
On Sun, Sep 19, 2010 at 9:20 AM, Nick Allen <nick.allen at comcast.net> wrote:
?Some GOOD news, at the Midwest VCF, Chris (from St
Paul, don't remember
last name) and Eric Kudzin were huge helps and took Jim S's recommendation
and repaired the 5V Op Amp fixing the 5V issue and now the Disk Drive SPINS!
Great news! I was so busy there I didn't even hear about this. It's
great to know we've got a helpful ccmp community coming together here
in the Chicago area. Really glad you made it to the show!
--
jht
4:48 p.m.
Glad to hear it was that. Hope that the mechanical bits can be made
to work as well.
How about setting up the cpu system, etc, have you assessed that part
yet? what about software, etc.
Jim
On 9/19/2010 7:20 AM, Nick Allen wrote:
Some GOOD news, at the Midwest VCF, Chris (from St
Paul, don't
remember last name) and Eric Kudzin were huge helps and took Jim S's
recommendation and repaired the 5V Op Amp fixing the 5V issue and now
the Disk Drive SPINS! We still need to repair the CRT and diagnose
the rest of the system, but we are making progress!!
Thank you Jim (for the amazing feat of properly diagnosing remotely
via schematics) and thank you Chris and Eric for your endless hours of
help at the VCF!'
I will keep everyone posted as we progress, Eric and I will be working
over the next several months to restore the Alto!
6:14 p.m.
<comes out from bushes> ah, that was me.
Was a great time and really a blast to dig into the Alto. We definitely
improvised, not having a stock of uA709 opamp on hand... we just bypassed
that regulator circuit and stuck a 7805 there instead, which was pilfered
from Vince Briel's spare parts stock for his
Altair8800micro kits.
Too much fun.
Good luck Nick and keep us posted.
Chris
On Sunday (09/19/2010 at 09:20AM -0500), Nick Allen wrote:
Some GOOD news, at the Midwest VCF, Chris (from St
Paul, don't remember
last name) and Eric Kudzin were huge helps and took Jim S's
recommendation and repaired the 5V Op Amp fixing the 5V issue and now
the Disk Drive SPINS! We still need to repair the CRT and diagnose the
rest of the system, but we are making progress!!
Thank you Jim (for the amazing feat of properly diagnosing remotely via
schematics) and thank you Chris and Eric for your endless hours of help
at the VCF!'
I will keep everyone posted as we progress, Eric and I will be working
over the next several months to restore the Alto!
--
Chris Elmquist
11:14 a.m.
On Monday (09/20/2010 at 07:26AM -0700), Al Kossow wrote:
On 9/19/10 6:14 PM, Chris Elmquist wrote:
That's right. It was definitely not intended as a long term fix.
Just something to move the ball forward while at the show. We tried
to be careful to do the mod so that it can be undone and the proper fix
(which is to replace the 709 op amp) applied.
Chris
--
Chris Elmquist
<comes out from bushes> ah, that was me.
we just bypassed
that regulator circuit and stuck a 7805 there instead
I don't know how long that will survive, since it is only a 1A regulator
dropping 10v (15 -> 5) 
11:49 a.m.
On 2010 Sep 19, at 6:14 PM, Chris Elmquist wrote:
<comes out from bushes> ah, that was me.
Was a great time and really a blast to dig into the Alto. We
definitely
improvised, not having a stock of uA709 opamp on hand... we just
bypassed
that regulator circuit and stuck a 7805 there instead, which was
pilfered
from Vince Briel's spare parts stock for his Altair8800micro kits.
Too much fun.
If the 709 was a TO-99 (can) package and you need to replace it, I have
lots of 741's in TO-99.
Just mentioning it in case it is difficult to find a 709 in TO-99. (DIP
should be easy to find something to substitute.)
Good luck Nick and keep us posted.
Chris
On Sunday (09/19/2010 at 09:20AM -0500), Nick Allen wrote:
> Some GOOD news, at the Midwest VCF, Chris (from St Paul, don't
> remember
> last name) and Eric Kudzin were huge helps and took Jim S's
> recommendation and repaired the 5V Op Amp fixing the 5V issue and now
> the Disk Drive SPINS! We still need to repair the CRT and diagnose
> the
> rest of the system, but we are making progress!!
>
> Thank you Jim (for the amazing feat of properly diagnosing remotely
> via
> schematics) and thank you Chris and Eric for your endless hours of
> help
> at the VCF!'
>
> I will keep everyone posted as we progress, Eric and I will be working
> over the next several months to restore the Alto!
3:15 p.m.
On 9/20/10 2:49 PM, Brent Hilpert wrote:
TO-99 709s are difficult to find, but not impossible. For most
applications I believe a 741 can be used as a drop-in replacement for a
709; this being a voltage regulator I'd guess it probably isn't all that
demanding on the 709's particular specifications.
It wouldn't be 100% historically correct, but if you think about it,
that would likely have been a reasonable repair method during this
machine's service lifetime.
I'd say do it.
-Dave
--
Dave McGuire
Port Charlotte, FL
Was a great
time and really a blast to dig into the Alto. We definitely
improvised, not having a stock of uA709 opamp on hand... we just bypassed
that regulator circuit and stuck a 7805 there instead, which was pilfered
from Vince Briel's spare parts stock for his Altair8800micro kits.
Too much fun.
If the 709 was a TO-99 (can) package and you need to replace it, I have
lots of 741's in TO-99.
Just mentioning it in case it is difficult to find a 709 in TO-99. (DIP
should be easy to find something to substitute.)
6:07 p.m.
On 2010 Sep 20, at 3:15 PM, Dave McGuire wrote:
On 9/20/10 2:49 PM, Brent Hilpert wrote:
TO-99 709s are difficult to find, but not impossible. For most
applications I believe a 741 can be used as a drop-in replacement for
a 709; this being a voltage regulator I'd guess it probably isn't all
that demanding on the 709's particular specifications.
It wouldn't be 100% historically correct, but if you think about it,
that would likely have been a reasonable repair method during this
machine's service lifetime.
I'd say do it.
The 741 was well available by the time of the Altos introduction, and
simpler to use than the 709. Mildly surprising to hear the Altos used
the 709, perhaps the 741 was still a fair bit more expensive.
Pins 1 & 5 (TO-99) connect to external compensation components on the
709, they are for offset null on the 741. One should probably snip off
or leave open those pins if replacing a 709 with a 741.
I think I have one 709 in TO-99 from my first op-amp project (a
square-wave generator) ca 1972.
Was a
great time and really a blast to dig into the Alto. We
definitely
improvised, not having a stock of uA709 opamp on hand... we just
bypassed
that regulator circuit and stuck a 7805 there instead, which was
pilfered
from Vince Briel's spare parts stock for his Altair8800micro kits.
Too much fun.
If the 709 was a TO-99 (can) package and you need to replace it, I
have
lots of 741's in TO-99.
Just mentioning it in case it is difficult to find a 709 in TO-99.
(DIP
should be easy to find something to substitute.) 
21 Sep
21 Sep
4:13 a.m.
On Monday (09/20/2010 at 10:10PM -0400), William Donzelli wrote:
That's what the part was! That would be what he needs.
Chris
--
Chris Elmquist
If the 709 was
a TO-99 (can) package and you need to replace it, I have lots
of 741's in TO-99.
I have new Motorola MC1709Gs in stock.
20 Sep
20 Sep
7:35 p.m.
On Monday (09/20/2010 at 11:49AM -0700), Brent Hilpert wrote:
On 2010 Sep 19, at 6:14 PM, Chris Elmquist wrote:
I'm sure Nick will appreciate the offer... unfortunately, the one that's
in there is a 14-pin DIP. I'm not remembering now if I saw a manufacturers
mark on the package but I do see now that Fairchild made a single 709 in
a 14-pin DIP...
Chris
--
Chris Elmquist
<comes out from bushes> ah, that was me.
Was a great time and really a blast to dig into the Alto. We
definitely
improvised, not having a stock of uA709 opamp on hand... we just
bypassed
that regulator circuit and stuck a 7805 there instead, which was
pilfered
from Vince Briel's spare parts stock for his Altair8800micro kits.
Too much fun.
If the 709 was a TO-99 (can) package and you need to replace it, I have
lots of 741's in TO-99.
Just mentioning it in case it is difficult to find a 709 in TO-99. (DIP
should be easy to find something to substitute.)
21 Sep
21 Sep
1:30 p.m.
I'm sure Nick will appreciate the offer...
unfortunately, the one that's
in there is a 14-pin DIP. I'm not remembering now if I saw a manufacturers
mark on the package but I do see now that Fairchild made a single 709 in
a 14-pin DIP...
Most of the time the 14 pin DIP has 6 pins on the ends (2 at one end, 4
at the other) unused, and the remaining 8 pins have the same conenctions
as the 8 pin DIP (or the TO99 isf you spread out the leads
appropriately). You should be able to fit an 8 pin op-amp onto that board
(not original,but it preserces the circuit design and it is the sort of
thing that would bave been done when the machine was in use).
-tony
20 Sep
20 Sep
1:27 p.m.
<comes out from bushes> ah, that was me.
Was a great time and really a blast to dig into the Alto. We definitely
improvised, not having a stock of uA709 opamp on hand... we just bypassed
that regulator circuit and stuck a 7805 there instead, which was pilfered
from Vince Briel's spare parts stock for his Altair8800micro kits.
Too much fun.
I think if i has a machine as rare as an Alto, I would try to keep the
circuitry as original as posisble. In other words, I'd not bung in a 3
terminal regulator hore.
The 709, IIRC, uses external compensation, while most more modern op-amps
don't. But that shou;ldn't be much of a problem for a PSU regulator
circuit. I would try to fidnm an op-amp that owuld work here (even you
can't stil lget a 709 anywhere...)
-tony
9:16 p.m.
Need to find the 14 pin opamp (as I am also a purest and want it to be
ORIGINAL), found a pair on ebay:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330471900022&rvr…
WAY to expensive, and I only need 1, anyone have one they might be able
to sell me, or able to find a cheaper source?
Also, Eric Kudzin spent some time trying to fix the CRT, we are making
progress and as part of the testing we need to test a KNOWN WORKING
computer on the Alto monitor/crt. I have a PET 2001, we made a custom
cable (it "should" work), anyone know if the PET video out will work on
the Alto monitor?
Here is the adapter:
http://lh6.ggpht.com/_lkddKjPsPFU/TJgv61uSNMI/AAAAAAAABhM/-n0SEds-o5g/_1020…
11:32 p.m.
Chips manufactured in the day of gold plated DIP leads are cheap at
$39.00. Nearly unobtainium.
I can check with some collectors, but I know that the subject just came
up involving some other IC's of similar vintage, and I suspect that
these are cheap. Hopefully someone has some in their junk if you can
get them for less.
On 9/20/2010 9:16 PM, Nick Allen wrote:
Need to find the 14 pin opamp (as I am also a purest
and want it to
be ORIGINAL), found a pair on ebay:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330471900022&rvr…
WAY to expensive, and I only need 1, anyone have one they might be
able to sell me, or able to find a cheaper source?
I didn't look, but if this is the part that is dropping your 15 v to 5 v
and it already was failed, buying two isn't such a bad move while you
can get them.
Jim
21 Sep
21 Sep
7:25 a.m.
On 9/20/10 9:16 PM, Nick Allen wrote:
Also, Eric Kudzin spent some time trying to fix the
CRT, we are making progress and as part of the testing we need to test a KNOWN WORKING
computer on the Alto
totally incompatible.
The Alto monitor timing is pretty unique. The display is portrait, 606 x 808 with
the high frequency scan from top to bottom. Overheating and horizontal deflection
failures are very common in Alto monitors. The most common cause of failure is that
the horizontal width coil overheats and unsolders itself from the PC board. Because the
horizontal scan occurs across the narrower dimension of the tube, a lot of power is
dissipated in the width coil. It also burns up the paper tube it is wound on, making
it impossible to adjust the width. I ended up rewinding a bunch of them recently using
new coil forms and heavier wire.
Horizonal and vertical drive are hardwired in the display hardware. You won't get a
raster until the display microcode is loaded and running, though, and you have a long
way to go before you're that far.
8:29 a.m.
Thanks Al,
We are doing component testing of all the electronics in the
monitor first, before we do any further testing with the actual alto.
We do see the tube glowing, also the transistors all seem to be
working. We are however NOT getting any static on the screen, I don't
think the flyback is outputting high voltage, we are working our way
backwards to find the culprit.
22 Sep
22 Sep
11:05 a.m.
Thanks Al,
We are doing component testing of all the electronics in the
monitor first, before we do any further testing with the actual alto.
We do see the tube glowing, also the transistors all seem to be
working. We are however NOT getting any static on the screen, I don't
think the flyback is outputting high voltage, we are working our way
backwards to find the culprit.
I seem to rememebr seeing schematics for the Alto monitor on bitsavers
(but I can't rememebr them in detail).
I assume you don't have an EHT voltmeter, otherwise you'd have measured
the fianl anode voltage on the CRT by now :-)
OK, the first thing to do is see how the CRT heater is powered (since you
know that's working). Most of the time it just comes from a PSU
regulator, but occasionally, it's powered by a little winding on the
flyback transfotmer. If the latter, then if the heater is glowing, you
know the horizotnal output staage is doing something.
Next masure the CRT pin voltages. On a monchrome CRT you'd expect,
perhaps, 700V on some of the electrodes, but not much more. Which means
the votlages are witin the range of most multimeters. If you can't find
suh voltages, it's a petty good bet you have problems in the horizontal
section.
One trick I hesitate to mention, since there's the posibilty of doing
damage, is to _momentarily_ short the cathode to grid (g1) on the CRT. By
removing hte -ve grid bias, you should get a very bright screen. But
don't leave thsoe electrodes shorted together, you can damage the CRT due
to excessive beam current. Just a quick flick with a bit of wire.
-tony
11:49 p.m.
On 9/22/2010 8:27 PM, Nick Allen wrote:
Not SEE static, but feel static
Nick, and others with Alto experience, I wonder if the system has
control over the video, and it may not fire until the firmware is
running, and ready for the display.
I had an experience with one in El Segundo at the XDS facility there
years ago, and played with a graphics program. One thing we did was
turn on one bit with the screen black (all 0, I assume) and then turn
off one bit with the screen white, just to see if it was noticeable.
I don't know if the program, whatever it was had control over the scan
or not, but it is possible that was firmware controlled. If the monitor
schematics exist, you might need to see if there is a control that
turned on the video, which may fire the high voltage on demand.
Jim
24 Sep
24 Sep
1:46 p.m.
I don't know if the program, whatever it was had
control over the scan
or not, but it is possible that was firmware controlled. If the monitor
schematics exist, you might need to see if there is a control that
turned on the video, which may fire the high voltage on demand.
I don't have the monitor schematics to hand (they're on bitsavers), but
it's entirely possible that there will be no horizontal drive (and thus
no HV) if there's no horizontal sync pulses from the Alto. Amnd that
might well be software controlled.
to the OP : What test gear do you have/ Do you have an EHT voltmeter (up
to about 20kV)? A 'scope? A multimeter?
-tony
6:27 p.m.
Tony,
Have access to a fluke multimeter, oscilloscope, eprom
programmer/reader, and a brilliant vintage computer repair technician
local to Chicago (Eric Kudzin), he is extremely helpful and taking the
lead on repairs, but we sometimes need help/advice/direction and ALL
your help on this listing is extremely helpful!
25 Sep
25 Sep
1:43 p.m.
Tony,
Have access to a fluke multimeter, oscilloscope, eprom
programmer/reader, and a brilliant vintage computer repair technician
local to Chicago (Eric Kudzin), he is extremely helpful and taking the
Exceellent. And you realise that the most important piece of equipment
for repairing something is not electronic, it's a brain :-).
lead on repairs, but we sometimes need
help/advice/direction and ALL
your help on this listing is extremely helpful!
No problem/. That, surely, is one thing the classiccmp list is for.
Exchanging repair/diagnostic tips, etc. While not its only use (and nor
should it be), it's certain;y a very important use for the lsit.
Anyway, I've had another look at the monitor info on bitsavers. It
appears it's a Ball Brothers monitor, and the information is a reprint of
the original service manual for the monitor (makes sense). There's a
fairly good secion in that manual on diagnosing faults.
If you have that monitor (and it's not certain, Xerox may well have used
other manufacturer's monitors -- the PERQ, for example, may have had a
VMI, KME, Moniterm or 3 rivers monitor depending on the model!), yuo want
to look at the that manual carefully.
Firstly, the horizontal fdeflection system, which as usual, produces the
high voltages for the CRt, wil lrun without sync pulses. So you should
get HV without the Alto doing anything.
Secondly, the mains PSU prodcues 2 votlages. One is the 6.3V AC supplky
to the CRT heater (which implies the heater will be alight even if just
about anything else has failed). The other is regulated down to 55V and
suppleis the monitor electronics. The manual suggests you measure this
first since if there is a short or overload, the regulator circuit will
shut down. IIt then suggests isolating the verticla and horizontal
defleciton circuits by removing connetors (details are in the manual) to
see what is fialing.
If you have that model of monitor, I can see no reason not to follow that
procedure...
-tony
26 Sep
26 Sep
10:56 a.m.
On 9/25/10 1:43 PM, Tony Duell wrote:
You missed that there is no horizontal oscillator.
Mea clupa! You are absolutely correct, of course. This will teach me to
quickly glance at schematics and not fully analyse them.
I looked at the monitor scheamtic and saw the horizontal system had half
adozen transistors in it, and what looked to be timing networks. So I
assumed, incorrectly, that it was an oscillator. I failed to notice there
was no feedback path anywhere.
To the OP :
I posted some incorrect information yesterday. The Alto monitor, at least
if it's the Ball Brothers one shown in the schematics on bitsavers, will
_NOT_ produce the high voltages (including the CRT anode voltage) unless
it is getting horizontal sync pulsse ('drive pulses' is probably more
accurate) from the Alto itself. I don't know enough about the Alto to
know if it will always proeduce such sync pulses, or whether you have to
have the right software or microcode loadrd.
I thnik what I would do, given that you have a 'scope, is to see if the
Alto is producing said horizontal sync pulses. If not, then figure out
why (it may not be a hardware problem, I can take a look at the Alto
video scehamtics to see if I can figrue out if there's any software
control). When you arr getting sync pulses, then troubleshoot the monitor.
-tony
So you should
get HV without the Alto doing anything.
4:52 p.m.
Excellent! This explains a lot. The CRT wasn't producing high
voltage when connected to the PET or when powered on stand alone. I do
believe it WAS producing high voltage when connected to the alto, hence
the video card on the alto should then be outputting signal! Make
sense, am I understanding your post correctly?
27 Sep
27 Sep
11:32 a.m.
Excellent! This explains a lot. The CRT wasn't producing high
voltage when connected to the PET or when powered on stand alone. I do
believe it WAS producing high voltage when connected to the alto, hence
the video card on the alto should then be outputting signal! Make
sense, am I understanding your post correctly?
Yes, that sounds right.
The monitor need a horizontal sync/drive signal from the Alto for the HV
section to operate. Without it (for excample if the poniteir is powered
on its own), there will be bo high voltage.
This singal also needs to be the right frequency, which probably explains
wny it didn't work when connected to the PET
In fact driving it off-frequency could, I think, do damage, much as
plugging an IBM5151 MDA monuitor into a CGA card causes magic smoke to
escape.
-tony
22 Sep
22 Sep
9:32 p.m.
New subject: 8 mm tapes
Hi
I've added a scsi tape drive to my collection. I hope to use
it with my Sparcbook. It is a Sun box with a sticker on it saying
that it is a EXB-8500C drive. Do I need special 8mm tapes
with it? How do I know what tapes will work with it?
I've never dealt with these drives before.
Dwight
9:43 p.m.
New subject: 8 mm tapes
http://www-esd.fnal.gov/esd/catalog/main/exabyte/8500-spec.htm
8mm EXATAPE, 112m)
EXB-8500: 5 GB
EXB-8500c: 10 GB (compressed)*
http://cgi.ebay.com/FujiFilm-8mm-Data-Tape-112M-5GB-10GB-/2757123687
----- Original Message -----
From: "dwight elvey" <dkelvey at hotmail.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Thursday, September 23, 2010 12:32 AM
Subject: 8 mm tapes
Hi
I've added a scsi tape drive to my collection. I hope to use
it with my Sparcbook. It is a Sun box with a sticker on it saying
that it is a EXB-8500C drive. Do I need special 8mm tapes
with it? How do I know what tapes will work with it?
I've never dealt with these drives before.
Dwight
=
10:32 p.m.
New subject: 8 mm tapes
On 22 Sep 2010 at 21:32, dwight elvey wrote:
Hi
I've added a scsi tape drive to my collection. I hope to use
it with my Sparcbook. It is a Sun box with a sticker on it saying that
it is a EXB-8500C drive. Do I need special 8mm tapes with it? How do I
know what tapes will work with it? I've never dealt with these drives
before. Dwight
Hi Dwight,
I have a bunch of new unused 90m Maxell 8mm tapes. If you'd like, I
can send you a few. Heaven knows, they're not going to get used
here.
--Chuck
23 Sep
23 Sep
6:36 a.m.
New subject: 8 mm tapes
Hi Chuck
That would be great. Would it still work OK as the spec says
112m? I can buy three 160 EXABYTE labled tapes
on ebay for not a hole lot as well. I own you a disk
from the Canon Cat so you can look at it as well.
I tend to get side tracked.
So, what all seem to be saying is that there is no
special length requirement. I don't have to get exactly
112m tapes?
Dwight
From: cclist at sydex.com
To: cctalk at classiccmp.org
Date: Wed, 22 Sep 2010 22:32:13 -0700
Subject: Re: 8 mm tapes
On 22 Sep 2010 at 21:32, dwight elvey wrote:
Hi
I've added a scsi tape drive to my collection. I hope to use
it with my Sparcbook. It is a Sun box with a sticker on it saying that
it is a EXB-8500C drive. Do I need special 8mm tapes with it? How do I
know what tapes will work with it? I've never dealt with these drives
before. Dwight
Hi Dwight,
I have a bunch of new unused 90m Maxell 8mm tapes. If you'd like, I
can send you a few. Heaven knows, they're not going to get used
here.
--Chuck
10:09 a.m.
New subject: 8 mm tapes
On 23 Sep 2010 at 6:36, dwight elvey wrote:
Hi Chuck
That would be great. Would it still work OK as the spec says
112m? I can buy three 160 EXABYTE labled tapes
on ebay for not a hole lot as well. I own you a disk
from the Canon Cat so you can look at it as well.
I tend to get side tracked.
So, what all seem to be saying is that there is no
special length requirement. I don't have to get exactly
112m tapes?
Dwight
Hi Dwight,
Would you rather have the 112m tapes? I've got a bunch of those too,
but I preferred the 90m ones as they're a bit sturdier (thicker
substrate). Length isn't critical for the drive--Exabyte even sold
60m tapes for their drives.
Give me your mailing address and I'll pack a small flat-rate USPS box
full of them. $5 to cover shipping is all I'd ask.
--Chuck
P.S. That's the awful thing about doing media conversion--stuff
seems to pile up as no one wants it back. I've got boxes and boxes
of 5.25" floppies from old customer jobs, for example. My latest job
involves a pile of hard-sector 8" floppies. Your 8mm tapes, however,
will be new--only the carboard packaging removed to save space.
10:15 a.m.
New subject: 8 mm tapes
Sorry List, that last message to Dwight was supposed to be off-list.
--Chuck
9:34 p.m.
New subject: 8 mm tapes
Hi
Two or three tapes would be more than I'd expect to ever use.
My address:
Dwight Elvey
784 Corlista dr
San Jose, California.
95128
When I get the box, I'll send back the shipping
and a floppy with the Canon Cat format and data
on.
Dwight
From: cclist at sydex.com
To: cctalk at classiccmp.org
Date: Thu, 23 Sep 2010 10:09:52 -0700
Subject: RE: 8 mm tapes
On 23 Sep 2010 at 6:36, dwight elvey wrote:
Hi Chuck
That would be great. Would it still work OK as the spec says
112m? I can buy three 160 EXABYTE labled tapes
on ebay for not a hole lot as well. I own you a disk
from the Canon Cat so you can look at it as well.
I tend to get side tracked.
So, what all seem to be saying is that there is no
special length requirement. I don't have to get exactly
112m tapes?
Dwight
Hi Dwight,
Would you rather have the 112m tapes? I've got a bunch of those too,
but I preferred the 90m ones as they're a bit sturdier (thicker
substrate). Length isn't critical for the drive--Exabyte even sold
60m tapes for their drives.
Give me your mailing address and I'll pack a small flat-rate USPS box
full of them. $5 to cover shipping is all I'd ask.
--Chuck
P.S. That's the awful thing about doing media conversion--stuff
seems to pile up as no one wants it back. I've got boxes and boxes
of 5.25" floppies from old customer jobs, for example. My latest job
involves a pile of hard-sector 8" floppies. Your 8mm tapes, however,
will be new--only the carboard packaging removed to save space.
10:03 p.m.
New subject: 8 mm tapes
Sorry All
I just made the same mistake Chuck did. How silly of me.
Dwight
From: dkelvey at hotmail.com
To: cctalk at classiccmp.org
Subject: RE: 8 mm tapes
Date: Thu, 23 Sep 2010 21:34:30 -0700
Hi
Two or three tapes would be more than I'd expect to ever use.
My address:
---snip---
6:39 a.m.
New subject: 8 mm tapes
On Thursday, September 23, 2010, dwight elvey wrote:
Hi
I've added a scsi tape drive to my collection. I hope to use
it with my Sparcbook. It is a Sun box with a sticker on it saying
that it is a EXB-8500C drive. Do I need special 8mm tapes
with it? How do I know what tapes will work with it?
I've never dealt with these drives before.
Especially for the low-capacity 8500/8200 Exabyte drives, 8mm video tape
was commonly used with the drives.
Some may say that "isn't reliable", but 8mm drives tend to not have
great reliability due to their helical scan head, including the fact
that they tend to drift out of alignment over time.
Pat
--
Purdue University Research Computing --- http://www.rcac.purdue.edu/
The Computer Refuge --- http://computer-refuge.org
6:44 a.m.
New subject: 8 mm tapes
On 9/23/10 9:39 AM, Patrick Finnegan wrote:
Video was commonly *tried* with 8500s, but not many people got very
far. Our error rates with "good" video tapes were upwards of 20%.
I've
added a scsi tape drive to my collection. I hope to use
it with my Sparcbook. It is a Sun box with a sticker on it saying
that it is a EXB-8500C drive. Do I need special 8mm tapes
with it? How do I know what tapes will work with it?
I've never dealt with these drives before.
Especially for the low-capacity 8500/8200 Exabyte drives, 8mm video tape
was commonly used with the drives. Some may say that "isn't reliable", but
8mm drives tend to not have
great reliability due to their helical scan head, including the fact
that they tend to drift out of alignment over time.
"Write-only media", yes. I've never seen a tape as unreliable as an
8200/8500.
-Dave
--
Dave McGuire
Port Charlotte, FL
6:52 a.m.
New subject: 8 mm tapes
IBM sold the 20/40GB Mammoth 8MM drives so reliability must have been decent
at that point (different tape formulation I assume).
I linked to an ebay seller who had the correct tapes for that 8500 drive for
$4 shipped, not going to find anything much cheaper (even if free you are
paying for postage).
----- Original Message -----
From: "Dave McGuire" <mcguire at neurotica.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Thursday, September 23, 2010 9:44 AM
Subject: Re: 8 mm tapes
On 9/23/10 9:39 AM, Patrick Finnegan wrote:
Video was commonly *tried* with 8500s, but not many people got very far.
Our error rates with "good" video tapes were upwards of 20%.
I've added a scsi tape drive to my collection. I hope to use
it with my Sparcbook. It is a Sun box with a sticker on it saying
that it is a EXB-8500C drive. Do I need special 8mm tapes
with it? How do I know what tapes will work with it?
I've never dealt with these drives before.
Especially for the low-capacity 8500/8200 Exabyte drives, 8mm video tape
was commonly used with the drives. Some may say that "isn't reliable",
but 8mm drives tend to not have
great reliability due to their helical scan head, including the fact
that they tend to drift out of alignment over time.
"Write-only media", yes. I've never seen a tape as unreliable as an
8200/8500.
-Dave
--
Dave McGuire
Port Charlotte, FL
7:06 a.m.
New subject: 8 mm tapes
On 9/23/10 9:52 AM, Teo Zenios wrote:
IBM sold the 20/40GB Mammoth 8MM drives so reliability
must have been
decent at that point (different tape formulation I assume).
That was easily a decade, possibly more, after the drives we're
talking about. I had "write-only" experiences with 8200 and 8500 drives
in 1992; they were new at that time. I'm sure subsequent development
improved error correction, head design, tape wear, and just about
everything else.
-Dave
--
Dave McGuire
Port Charlotte, FL
7:52 a.m.
New subject: 8 mm tapes
On 9/23/2010 6:44 AM, Dave McGuire wrote:
On 9/23/10 9:39 AM, Patrick Finnegan wrote:
<snip>
"Write-only media", yes. I've never seen a tape as unreliable as an
8200/8500.
-Dave
I have tapes that are 20 years old. All are readable. The error rate
is lower than with 1/2" though the 1/2" tapes can be manually nursed
back by alignment play.
I used video tapes in the 8200's w/o any problem. All are still readable.
Sample size was about 30 tapes in my case, not hundreds. YMMV
Jim
24 Sep
24 Sep
6:43 a.m.
New subject: 8 mm tapes
On 9/23/10 10:52 AM, jim s wrote:
MMDV (My Mileage Definitely Varied) :) I too have some that are
readable, mostly from Exabyte 8200s (2.3GB) but some from 8500s (5GB).
At least they were still readable a few years ago. These were
definitely the exception though. The company I worked for around '92
had an 8200 and a bunch of video tapes when I got there, but had never
set it up. My first results were ok, but the second set of tapes were
full of errors. I guess the first time I just got lucky. We got into
the habit of running a head-cleaning tape after every two or three uses
of the drive; that helped a bit.
My boss insisted on getting an 8500, though I wasn't convinced of the
efficacy of the technology. I wanted to just stick with our trusty
QIC-150 and use a bunch of tapes for incremental backups. He wanted
full backups every time (I think he didn't really understand the
incremental backup concept) which made the 150MB QIC-150 tapes
impractical. Results with video tapes for the 8500 were terrible; not a
single tape worked well. We bought data-grade tapes (Sony QG-112M I
think) and that improved things, but it was still pretty bad.
At my next company we had a brief dabbling with an 8200 but replaced
it with a 4mm DAT, with which I had had some experience at a small
consulting job. I liked DAT at the time, but hadn't really put volumes
of data through it. I wish I had, because I fought tooth and nail to
get us a DAT drive at that company, but boy was that a mistake. They
were only marginally more reliable than the 8mm Exabytes all told.
It took a few years of running double backups until we got a truly
reliable tape system: DLT. That was 1995, and I am still sold on DLT
(and its descendants) now. Super fast, super reliable. My home
network's backups are running to a 64-tape juke with four SDLT-220 drives.
I also found your comment regarding 1/2" tapes interesting. I'm
assuming you mean 9-track, as there are many 1/2" tapes that aren't. In
my experience ("mileage"! ;)) 9-track is the only tape format that's
anywhere near as reliable as a DLT. Of course we're talking 150MB vs.
200+GB per tape (for my current drives) so it's very much apples and
oranges. 9-track tape reliability depends very much on the particular
drive in use. (though I suppose that's true for any kind of tape)
-Dave
--
Dave McGuire
Port Charlotte, FL
<snip>
"Write-only media", yes. I've never seen a tape as unreliable as an
8200/8500.
I have tapes that are 20 years old. All are readable. The error rate is
lower than with 1/2" though the 1/2" tapes can be manually nursed back
by alignment play.
I used video tapes in the 8200's w/o any problem. All are still readable.
Sample size was about 30 tapes in my case, not hundreds. YMMV
9:46 a.m.
New subject: 8 mm tapes
On 24 Sep 2010 at 9:43, Dave McGuire wrote:
It took a few years of running double backups until
we got a truly
reliable tape system: DLT. That was 1995, and I am still sold on DLT
(and its descendants) now. Super fast, super reliable. My home
network's backups are running to a 64-tape juke with four SDLT-220
drives.
We spent about 13 years recommending backup media for a number of
government agencies, starting in about 1988. This was in a field
application--i.e., not a permanent installation, but rather a "snatch
and grab" sort of affair.
At the time, we standardized on SCSI, being one of the few external-
device interfaces with a standard attached to it.
Intially, the most popular was the Iomega Bernoulli drives (5.25").
Heavy, yes, but very reliable and reasonably fast. A few also used
the DC-600 (6150, 6250) size QIC media. Not quite as
straightforward as Bernoulli, but all in all, not bad.
DDS (4mm tape) was a nightmare. About all the devices had going for
them was cost (for read-after-write medium, it was pretty good) and
capacity. I've not found long-term (>10 years) stability to be very
good.
8mm (Exabyte) tape was most popular with the larger agencies and
performed quite well. The biggest problem is that it was Exabyte-
proprietary and so the drives were single-sourced.
After that, the next step was high-capacity MO (e.g. PMC Apex 4GB).
The medium wasn't bad, but the drives weren't made for field use and
failed frequently. PMC got to be overwhelmed with their swap-repair
service and eventually declared bankruptcy.
DLT was briefly popular (reliability was great), media and drive cost
was high, but using commodity hard drives eventually won out.
For me, there are always surprises. I recently came across a cache
of backup tapes I made in 1988 using an Irwin (EZTape?) DC-1000
minicart drive. Every single one of the dozen backups was readable.
Sometimes, you just never can tell.
But you can keep your Datasonix Pereos drives. One of the largest
publicity blitzes for a non-working product that I've ever seen.
--Chuck
25 Sep
25 Sep
2:18 p.m.
New subject: 8 mm tapes
I have several hundred extra tapes, including the 8mm 112, 160, and 170. If
anyone has need of any, feel free to send me your wish list off list.
Thanks, Paul
On Fri, Sep 24, 2010 at 11:46 AM, Chuck Guzis <cclist at sydex.com> wrote:
On 24 Sep 2010 at 9:43, Dave McGuire wrote:
It took a few years of running double backups
until we got a truly
reliable tape system: DLT. That was 1995, and I am still sold on DLT
(and its descendants) now. Super fast, super reliable. My home
network's backups are running to a 64-tape juke with four SDLT-220
drives.
We spent about 13 years recommending backup media for a number of
government agencies, starting in about 1988. This was in a field
application--i.e., not a permanent installation, but rather a "snatch
and grab" sort of affair.
At the time, we standardized on SCSI, being one of the few external-
device interfaces with a standard attached to it.
Intially, the most popular was the Iomega Bernoulli drives (5.25").
Heavy, yes, but very reliable and reasonably fast. A few also used
the DC-600 (6150, 6250) size QIC media. Not quite as
straightforward as Bernoulli, but all in all, not bad.
DDS (4mm tape) was a nightmare. About all the devices had going for
them was cost (for read-after-write medium, it was pretty good) and
capacity. I've not found long-term (>10 years) stability to be very
good.
8mm (Exabyte) tape was most popular with the larger agencies and
performed quite well. The biggest problem is that it was Exabyte-
proprietary and so the drives were single-sourced.
After that, the next step was high-capacity MO (e.g. PMC Apex 4GB).
The medium wasn't bad, but the drives weren't made for field use and
failed frequently. PMC got to be overwhelmed with their swap-repair
service and eventually declared bankruptcy.
DLT was briefly popular (reliability was great), media and drive cost
was high, but using commodity hard drives eventually won out.
For me, there are always surprises. I recently came across a cache
of backup tapes I made in 1988 using an Irwin (EZTape?) DC-1000
minicart drive. Every single one of the dozen backups was readable.
Sometimes, you just never can tell.
But you can keep your Datasonix Pereos drives. One of the largest
publicity blitzes for a non-working product that I've ever seen.
--Chuck
24 Sep
24 Sep
12:39 p.m.
New subject: Backup regimen [was RE: 8 mm tapes]
From: Dave McGuire
Sent: Friday, September 24, 2010 6:44 AM
My boss insisted on getting an 8500, though I
wasn't convinced of the
efficacy of the technology. I wanted to just stick with our trusty
QIC-150 and use a bunch of tapes for incremental backups. He wanted
full backups every time (I think he didn't really understand the
incremental backup concept)
[snip]
When I worked at Cisco, on the IT side of the house, we preferred doing
nightly full backups, rather than the industry-standard monthly-full/
weekly-incremental/daily-incremental I was used to. Why? Because it
took a *lot* less time doing a restore to a known point in time, which
meant that a system down had us out of business for a couple of hours at
most. This was good enough on our MIPS boxes, and even better on our
HP-UX 9000/870 servers with three-way mirroring, where we could break
one volume out of the mirror and do backups from it, then merge it back
in.
I took the same backup regimen with me to XKL when I moved north, where
it saved a lot of engineering time following system crashes on the dev
boxen.
Rich Alderson
Vintage Computing Sr. Server Engineer
Vulcan, Inc.
505 5th Avenue S, Suite 900
Seattle, WA 98104
mailto:RichA at vulcan.com
mailto:RichA at LivingComputerMuseum.org
http://www.PDPplanet.org/
http://www.LivingComputerMuseum.org/
23 Sep
23 Sep
8:32 a.m.
New subject: 8 mm tapes
--- On Thu, 9/23/10, Patrick Finnegan <pat at computer-refuge.org> wrote:
I pretty regularly use video tapes in Exabyte 8200 drives on my Prime computers. The 8200
drives only store 2.5 gig per tape, and don't seem to be very picky about what tape
they use. Length is not important either - it'll just write until it runs out of tape,
there is no form of tape length accounting with these drives. I've found that the Fuji
brand 8mm video tape (available at the grocery store) works just fine in the 8200 drives.
I don't know if the 8500's are pickier or not.
I've found the Exabyte drives to be "pretty reliable". They're not as
reliable as nine track drives, but they are a lot more convenient. I run into less
problems with the tape media than I do with the interface between the drive and the
computer, but that's really more of an idiosyncrasy of the Prime SCSI controller than
the drive itself - although it is possible to get an 8200 into a weird mode where it's
just hung up and won't eject.
-Ian
Do I need
special 8mm tapes
with it? How do I know what tapes will work with it?
I've never dealt with these drives before.
Especially for the low-capacity 8500/8200 Exabyte drives,
8mm video tape
was commonly used with the drives.
6:41 a.m.
New subject: 8 mm tapes
On 9/23/10 12:32 AM, dwight elvey wrote:
I've added a scsi tape drive to my collection. I
hope to use
it with my Sparcbook. It is a Sun box with a sticker on it saying
that it is a EXB-8500C drive. Do I need special 8mm tapes
with it? How do I know what tapes will work with it?
I've never dealt with these drives before.
The 8200 (2.3GB) could use standard video tapes, but the 8500 (5GB)
requires data tapes. I tried video tapes in the 8500 when it came out,
but the error rates were horrendous.
-Dave
--
Dave McGuire
Port Charlotte, FL
10:13 a.m.
New subject: 8 mm tapes
On 23 Sep 2010 at 9:41, Dave McGuire wrote:
On 9/23/10 12:32 AM, dwight elvey wrote:
The 8200 (2.3GB) could use standard video tapes, but
the 8500 (5GB) > requires data tapes. I tried video tapes in the 8500 when it came
> out, but the error rates were horrendous.
Exabyte had warnings about the unreliability of 8mm video tape with
all of their later drives. I've got an 8700 here (as well as an
8500 and 8200) and 8mm videotapes don't work worth beans. Anyone
know if later 8mm media contained an ID burst like DDS media?
--Chuck
2:57 p.m.
New subject: 8 mm tapes
On Thu, 23 Sep 2010, Dave McGuire wrote:
On 9/23/10 12:32 AM, dwight elvey wrote:
And, I don't want to dump cold water on anyone's backup plans, but I've
found the 8mm DAT drives are by far the least reliable of any tape
system ever used here. Not necessarily in terms of data integrity, but in
terms of the _&)(*^^ drive itself dropping dead or developing problems.
Probably threw a half dozen of them away in the past ten years. I have
two working that I keep around only for laughs and data recovery.
Steve
--
I've added a scsi tape drive to my
collection. I hope to use
it with my Sparcbook. It is a Sun box with a sticker on it saying
that it is a EXB-8500C drive. Do I need special 8mm tapes
with it? How do I know what tapes will work with it?
I've never dealt with these drives before.
The 8200 (2.3GB) could use standard video tapes, but the 8500 (5GB)
requires data tapes. I tried video tapes in the 8500 when it came out, but
the error rates were horrendous.
24 Sep
24 Sep
6:47 a.m.
New subject: 8 mm tapes
On 9/23/10 5:57 PM, Steven Hirsch wrote:
And, I don't want to dump cold water on anyone's backup plans, but I've
found the 8mm DAT drives are by far the least reliable of any tape
system ever used here. Not necessarily in terms of data integrity, but
in terms of the _&)(*^^ drive itself dropping dead or developing problems.
Probably threw a half dozen of them away in the past ten years. I have
two working that I keep around only for laughs and data recovery.
There is no 8mm DAT. Do you mean 8mm Exabyte or 4mm DAT?
Not that it makes much difference, as one is just about as bad as the
other. I will never go near helical-scan media again. Give me DLT,
SDLT, and LTO and I'll be happy.
It's also kinda cool (for me) that DLT is a direct descendant of my
old favorite: the DEC TK-50. Yes, they're slow, finicky, and horribly
unreliable, but I have a lot of good memories from my later childhood
days hacking with TK-50s with my friends/mentors Ernie Perez, Bob Mader,
and Mike Santiago.
-Dave
--
Dave McGuire
Port Charlotte, FL
I've added a scsi tape drive to my collection. I
hope to use
it with my Sparcbook. It is a Sun box with a sticker on it saying
that it is a EXB-8500C drive. Do I need special 8mm tapes
with it? How do I know what tapes will work with it?
I've never dealt with these drives before.
The 8200 (2.3GB) could use standard video tapes, but the 8500 (5GB)
requires data tapes. I tried video tapes in the 8500 when it came out,
but the error rates were horrendous.
8:22 a.m.
New subject: 8 mm tapes
On Fri, 24 Sep 2010, Dave McGuire wrote:
On 9/23/10 5:57 PM, Steven Hirsch wrote:
And, I don't want to dump cold water on anyone's backup plans, but I've
found the 8mm DAT drives are by far the least reliable of any tape
system ever used here. Not necessarily in terms of data integrity, but
in terms of the _&)(*^^ drive itself dropping dead or developing problems.
Probably threw a half dozen of them away in the past ten years. I have
two working that I keep around only for laughs and data recovery.
There is no 8mm DAT. Do you mean 8mm Exabyte or 4mm DAT?
Slip of the brain... 8mm Exabyte, of course.
Interestingly enough, I never had much trouble at all with the 4mm drives.
Go figure. Haven't used any of the rotary head drives much since getting
my first DLT in 2005 or so.
I've added a scsi tape drive to my collection. I
hope to use
it with my Sparcbook. It is a Sun box with a sticker on it saying
that it is a EXB-8500C drive. Do I need special 8mm tapes
with it? How do I know what tapes will work with it?
I've never dealt with these drives before.
The 8200 (2.3GB) could use standard video tapes, but the 8500 (5GB)
requires data tapes. I tried video tapes in the 8500 when it came out,
but the error rates were horrendous. Not that it makes much difference, as one is just
about as bad as the
other. I will never go near helical-scan media again. Give me DLT, SDLT,
and LTO and I'll be happy.
We violently agree on that point... I used DLT7000 drives for a few years
until I grew tired of changing tapes every 1/2 hour. Currently quite
happy with the LTO-2 units. The eBay price-point is just right and I was
able to pickup a plastic storage-bin full of tapes for $20 at a flea
market. The tapes track usage and none of them were anywhere near the
point where I'd worry about data integrity.
Steve
--
23 Sep
23 Sep
11:09 a.m.
Nick Allen wrote:
Does 'static' here refer to random video noise/snow (which you will not
see on a monitor, only a TV), or the electrostaitc attraction of the
hairs on the back of your hand which you cna feel if you put your hand
near the screen The latter is possible (but not alaways detectable) on
any CRT monitor or TV.
-tony
We are however NOT getting any static on the
screen, I don't think
the flyback is outputting high voltage,
we are working our way backwards to find the
culprit.
Why on earth would you expect to see static on the screen? It's not a TV.
21 Sep
21 Sep
1:59 p.m.
The Alto monitor timing is pretty unique. The display
is portrait, 606
Is 'pretty unique' like 'slightly pregnant' ? :-)
x 808 with
the high frequency scan from top to bottom. Overheating and
horizontal deflection
failures are very common in Alto monitors. The most common cause of
failure is that>
the horizontal width coil overheats and unsolders itself from the PC
board. Because the
horizontal scan occurs across the narrower dimension of the tube, a
THis doesn't make sense to me. In the first part you're saying that th
high frequency scna in the vertical one -- that is that it's like a
normal monitor turned on its side. And they you talk about a width coil
which to me would always be associated with the fsster scan (horizontal
in anromal monitor), and yoy then say that it's the horizotnal scan on
the shorter tube axis (OK, I get that, it's a portait monitor) here too.
Can you tell me if the scan lines are horizontal or verticla here?
FWIW, the PEEQ portrait monbitors have horizontal scan lines alont the
shorter acixe of the screen.
lot of power is
dissipated in the width coil. It also burns up the paper tube it is
wound on, making
it impossible to adjust the width. I ended up rewinding a bunch of
them recently using
new coil forms and heavier wire.
Horizonal and vertical drive are hardwired in the display hardware.
You won't get a
raster until the display microcode is loaded and running, though, and
you have a long
way to go before you're that far.
Do you get syncpulses from the start? If so, at least things like the HV
should be coming up[ in the monitor (check this...)
If you are as insane as I am, you might make a little board with a clcok
oscillator and timing chain on it (TTL, FPGA, whatever you are
comfortable with) to genrate the sync pulses and some kind of fixed video
(corsshatch, checkerboard, etc)(. Then use that to test the monitor.
-tony
22 Sep
22 Sep
7:11 p.m.
Al,
Quick question regarding the Horizontal coil, do you remember how
the turns/wire gauge required for repairing the horizontal gauge, did
you wind it to a certain value, or simply a number of turns?
Thanks!
Nick
21 Sep
21 Sep
12:03 p.m.
On 2010 Sep 20, at 9:16 PM, Nick Allen wrote:
Need to find the 14 pin opamp (as I am also a purest
and want it to
be ORIGINAL), found a pair on ebay:
http://cgi.ebay.com/ws/eBayISAPI.dll?
ViewItem&item=330471900022&rvr_id=143156802920&crlp=1_263602_263622&UA=
%3F*F%3F&GUID=94213f4c1260a0269d971e47ff8e9d4d&itemid=330471900022%24&f
f4=263602_263622
WAY to expensive, and I only need 1, anyone have one they might be
able to sell me, or able to find a cheaper source?
Well, if you can't find a (reasonably-priced) 14-pinner, the pinout
patterns of the 8 and 14-pin DIP versions are the same, so an 8-pin is
a drop-in replacement for the the 14-pin.
Begs the question of why the 14-pin version was ever produced, machine
insertion/handling perhaps.
I have a couple of 8-pin DIP 741s (UA741C) from 1974 (7409).
6:29 p.m.
New subject: DIP packages (was Re: Help resurrect my Xerox Alto)
Brent Hilpert wrote:
Well, if you can't find a (reasonably-priced)
14-pinner, the pinout
patterns
of the 8 and 14-pin DIP versions are the same, so an
8-pin is a drop-in
replacement for the the 14-pin.
Begs the question of why the 14-pin version was ever
produced,
machine insertion/handling perhaps.
Perhaps. Also the 14-pin DIP was probably invented and standardized
(TO-116) several years before the 8-pin DIP. The 14-pin DIP appears to
date back to 1965 or earlier. I don't have any information suggesting
when the 8-pin DIP appeared. Was the ?A709 the first monolithic op-amp
offered in a DIP package? The earlier ?A702 was available in a 14-pin
DIP by 1976, but I don't think it was offered in a DIP at its introduction.
Fairchild had one part that was in a 36-pin DIP in 1969. I've never seen
that used for any other part.
Early on (late 1960s, early-to-mid 1970s), some of the Japanese
semiconductor vendors such as NEC seemed to like the 42-pin DIP.
10:38 p.m.
New subject: DIP packages (was Re: Help resurrect my Xerox Alto)
On 2010 Sep 21, at 6:29 PM, Eric Smith wrote:
Brent Hilpert wrote:
Good point. My subjective experience was that cans predominated for
such devices into the early 70's and then 8-pin DIPs replaced them.
The 1966 Fairchild catalog shows the 709 offered in only can and 10-pin
flat-pak, even though 14 & 16-pin DIPs are listed for other devices.
In support of your suggestion, the 1969 Motorola databook shows the 709
offered in can, flat-pak and 14-pin DIP.
There is no mention of an 8-pin DIP package anywhere in this 1969 Moto
book, they do show up by 1973 (another Moto book), including for the
709 and 741.
BTW, in the 1966 catalog, Fairchild states:
The Dual In-Line - the most significant contribution to
microcircuit packaging in recent years - is a Fairchild concept.
Well, if you can't find a (reasonably-priced)
14-pinner, the pinout
patterns
of the 8 and 14-pin DIP versions are the same, so
an 8-pin is a
drop-in
replacement for the the 14-pin.
Begs the question of why the 14-pin version was
ever produced,
machine insertion/handling perhaps.
Perhaps. Also the 14-pin DIP was probably invented and standardized
(TO-116) several years before the 8-pin DIP. The 14-pin DIP appears to
date back to 1965 or earlier. I don't have any information suggesting
when the 8-pin DIP appeared. Was the ?A709 the first monolithic op-amp
offered in a DIP package? The earlier ?A702 was available in a 14-pin
DIP by 1976, but I don't think it was offered in a DIP at its
introduction. Fairchild had one part that was in a 36-pin DIP in
1969. I've never
seen that used for any other part.
Early on (late 1960s, early-to-mid 1970s), some of the Japanese
semiconductor vendors such as NEC seemed to like the 42-pin DIP.
22 Sep
22 Sep
12:55 p.m.
New subject: DIP packages (was Re: Help resurrect my Xerox Alto)
Fairchild had one part that was in a 36-pin DIP in
1969. I've never seen=20
that used for any other part.
Now that's one I've never seen...
Early on (late 1960s, early-to-mid 1970s), some of the Japanese=20
semiconductor vendors such as NEC seemed to like the 42-pin DIP.
Seen those often enough...
I've used at least one chip in a 52 pin DIP (0.9" wide, an 8X300 series
microcontroller)), and IIRC a 10 pin DIP (some kind of clock driver I think).
-tony
9:26 p.m.
New subject: DIP packages & the 555
While looking around for a little about the 8-pin DIP package, I
checked into the 555, as it was introduced about the same time as the
8-pin DIP appeared. This site (albeit a 2nd-source, not direct ref)
says the 555 in 8-pin DIP was introduced in 1971 (page 2):
http://semiconductormuseum.com/Transistors/LectureHall/Camenzind/
Camenzind_Index.htm
But what I was surprised about was the statement about the 555 still
selling a billion units in 2003. I thought it had faded from popularity
since the '70/'80's as I can't recall seeing one in a new product in
many years. Apparently I'm not looking hard enough. Where are all these
555's going?
23 Sep
23 Sep
5:24 a.m.
New subject: DIP packages & the 555
On 22/09/2010 10:26 PM, Brent Hilpert wrote:
While looking around for a little about the 8-pin DIP
package, I
checked into the 555, as it was introduced about the same time as the
8-pin DIP appeared. This site (albeit a 2nd-source, not direct ref)
says the 555 in 8-pin DIP was introduced in 1971 (page 2):
http://semiconductormuseum.com/Transistors/LectureHall/Camenzind/Camenzind_…
But what I was surprised about was the statement about the 555 still
selling a billion units in 2003. I thought it had faded from
popularity since the '70/'80's as I can't recall seeing one in a new
product in many years. Apparently I'm not looking hard enough. Where
are all these 555's going?
who knows? But they sure must sell alot of embeded cpu's for all the usb
crap out today.
ben.
7:06 a.m.
New subject: DIP packages & the 555
On 9/23/10 12:26 AM, Brent Hilpert wrote:
While looking around for a little about the 8-pin DIP
package, I checked
into the 555, as it was introduced about the same time as the 8-pin DIP
appeared. This site (albeit a 2nd-source, not direct ref) says the 555
in 8-pin DIP was introduced in 1971 (page 2):
http://semiconductormuseum.com/Transistors/LectureHall/Camenzind/Camenzind_…
But what I was surprised about was the statement about the 555 still
selling a billion units in 2003. I thought it had faded from popularity
since the '70/'80's as I can't recall seeing one in a new product in
many years. Apparently I'm not looking hard enough. Where are all these
555's going?
A common use of 555s is as a PWM generator for large battery-powered
tools such as drills, power screwdrivers, and saws. These alone account
for quite a few 555s.
There was also one in my recently-replaced dishwasher (built around
2000) that timed one of the cycles. I think this was one of the few
times I actually saw a 555 used as a "timer". ;)
I designed 555s into a commercial product in 2002 and again in 2004.
I needed a ~455KHz carrier generator for an IR data transmitter, and a
555 was the easiest way to do it.
-Dave
--
Dave McGuire
Port Charlotte, FL
9:25 a.m.
New subject: DIP packages & the 555
Quoting Dave McGuire <mcguire at neurotica.com>:
I designed 555s into a commercial product in 2002
and again in
2004. I needed a ~455KHz carrier generator for an IR data
transmitter, and a 555 was the easiest way to do it.
Would a crystal oscilator not have been beter for this ? I seem to
remember 555s as having a rep for not being perticually
accurate.....though I guess if it was good enough for your app, it's
prolly the simplest/cheapest solution.
Cheers.
Phill.
----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.
9:38 a.m.
New subject: DIP packages & the 555
On 9/23/10 12:25 PM, afra at aurigae.demon.co.uk wrote:
Well sure, a crystal oscillator would've been a lot more stable, but
the receiver (Vishay TSOP-7000, a really nice device) has a VERY wide
tolerance for its carrier frequency. Further, this was for an
indoor-only application, so thermal drift wasn't going to be much of a
problem either. It worked very well.
-Dave
--
Dave McGuire
Port Charlotte, FL
I designed
555s into a commercial product in 2002 and again in 2004. I
needed a ~455KHz carrier generator for an IR data transmitter, and a
555 was the easiest way to do it.
Would a crystal oscilator not have been beter for this ? I seem to
remember 555s as having a rep for not being perticually
accurate.....though I guess if it was good enough for your app, it's
prolly the simplest/cheapest solution.
10:23 a.m.
New subject: DIP packages & the 555
On 9/23/10 12:26 AM, Brent Hilpert wrote:
While looking around for a little about the 8-pin DIP
package, I
checked into the 555, as it was introduced about the same time as
the 8-pin DIP appeared. This site (albeit a 2nd-source, not direct
ref) says the 555 in 8-pin DIP was introduced in 1971 (page 2):
http://semiconductormuseum.com/Transistors/LectureHall/Camenzind/Cam
enzind_Index.htm
But what I was surprised about was the statement about the 555 still
selling a billion units in 2003. I thought it had faded from
popularity since the '70/'80's as I can't recall seeing one in a new
product in many years. Apparently I'm not looking hard enough. Where
are all these 555's going?
8 pin DIPs were around in the 60s for linear products. Motorola
referred to them as their "Case 626" and used them for a lot of
consumer products such as the MC1350 IF amplifier. There was even a
4-pin DIP (Case 629) for the MFC4000 series of transistor arrays.
The NE555 for analog-minded folks is a hugely useful IC. Every
couple of months it seems that there's a circuit in EDN or Electronic
Design using one.
I've lately seen one used as a switching boost regulator. I've often
wondered if the NE555 (and 556) isn't the single most popular IC in
history.
--Chuck
11:01 a.m.
New subject: DIP packages & the 555
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-
bounces at classiccmp.org] On Behalf Of Chuck Guzis
Sent: Thursday, September 23, 2010 10:24 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: DIP packages & the 555
On 9/23/10 12:26 AM, Brent Hilpert wrote:
My favorite story about the 555 has nothing to do with its function, but rather its form.
I was working at an electronics store and a customer came in with a desperate need for a
555 (a radio station was off the air until the part was replaced in some critical circuit
that should probably have been redundant in the first place). I fetched our *last* 555
from the warehouse and noted that, in addition to the four legs coming out of each side,
there was one coming out the end! Of course, the jokes immediately started about the male
version of the chip, and we were actually reluctant to sell our 'breeding stock'
555 and speculated on how it had escaped from the 555 ranch. But alas, the customer
really REALLY needed the part, and off it went.... I've never seen another like it -
although to be honest, I haven't expended much (any) energy in looking for one. --
Ian
While looking around for a little about the 8-pin
DIP package, I
checked into the 555, as it was introduced about the same time as
the 8-pin DIP appeared. This site (albeit a 2nd-source, not direct
ref) says the 555 in 8-pin DIP was introduced in 1971 (page 2):
http://semiconductormuseum.com/Transistors/LectureHall/Camenzind/Cam
enzind_Index.htm
But what I was surprised about was the statement about the 555 still
selling a billion units in 2003. I thought it had faded from
popularity since the '70/'80's as I can't recall seeing one in a new
product in many years. Apparently I'm not looking hard enough. Where
are all these 555's going?
8 pin DIPs were around in the 60s for linear products. Motorola
referred to them as their "Case 626" and used them for a lot of
consumer products such as the MC1350 IF amplifier. There was even a
4-pin DIP (Case 629) for the MFC4000 series of transistor arrays.
The NE555 for analog-minded folks is a hugely useful IC. Every
couple of months it seems that there's a circuit in EDN or Electronic
Design using one.
I've lately seen one used as a switching boost regulator. I've often
wondered if the NE555 (and 556) isn't the single most popular IC in
history.
--Chuck
11:16 a.m.
New subject: DIP packages & the 555
On 23 Sep 2010 at 11:01, Ian King wrote:
My favorite story about the 555 has nothing to do with
its function,
but rather its form. I was working at an electronics store and a
customer came in with a desperate need for a 555 (a radio station was
off the air until the part was replaced in some critical circuit that
should probably have been redundant in the first place). I fetched
our *last* 555 from the warehouse and noted that, in addition to the
four legs coming out of each side, there was one coming out the end!
Of course, the jokes immediately started about the male version of the
chip, and we were actually reluctant to sell our 'breeding stock' 555
and speculated on how it had escaped from the 555 ranch. But alas,
the customer really REALLY needed the part, and off it went.... I've
never seen another like it - although to be honest, I haven't expended
much (any) energy in looking for one.
I wonder if this wasn't part of the leadframe that had missed being
sheared off. If you carefully inspect a few older plastic DIPs, you
can often spot the glint of the leadframe "tail" on the "bottom" end
of the DIP.
--Chuck
12:09 p.m.
New subject: DIP packages & the 555
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-
bounces at classiccmp.org] On Behalf Of Chuck Guzis
Sent: Thursday, September 23, 2010 11:17 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: RE: DIP packages & the 555
On 23 Sep 2010 at 11:01, Ian King wrote:
I'm sure that's the explanation - but I have an odd sense of humor. :-)
My favorite story about the 555 has nothing to do
with its function,
but rather its form. I was working at an electronics store and a
customer came in with a desperate need for a 555 (a radio station was
off the air until the part was replaced in some critical circuit that
should probably have been redundant in the first place). I fetched
our *last* 555 from the warehouse and noted that, in addition to the
four legs coming out of each side, there was one coming out the end!
Of course, the jokes immediately started about the male version of
the
chip, and we were actually reluctant to sell our
'breeding stock' 555
and speculated on how it had escaped from the 555 ranch. But alas,
the customer really REALLY needed the part, and off it went.... I've
never seen another like it - although to be honest, I haven't
expended
much (any) energy in looking for one.
I wonder if this wasn't part of the leadframe that had missed being
sheared off. If you carefully inspect a few older plastic DIPs, you
can often spot the glint of the leadframe "tail" on the "bottom" end
of the DIP.
--Chuck
11:49 a.m.
New subject: DIP packages & the 555
On 2010 Sep 23, at 10:23 AM, Chuck Guzis wrote:
On 9/23/10 12:26 AM, Brent Hilpert wrote:
Cases 626 & 629 are not present in the 1969 Motorola Databook, however.
From what I see the devices you mention are 70's products. In my
(limited) search the earliest mention or ref for use of the 8-pin I
have found is 1971 (the 555).
While looking around for a little about the 8-pin
DIP package, I
checked into the 555, as it was introduced about the same time as
the 8-pin DIP appeared. This site (albeit a 2nd-source, not direct
ref) says the 555 in 8-pin DIP was introduced in 1971 (page 2):
http://semiconductormuseum.com/Transistors/LectureHall/Camenzind/Cam
enzind_Index.htm
But what I was surprised about was the statement about the 555 still
selling a billion units in 2003. I thought it had faded from
popularity since the '70/'80's as I can't recall seeing one in a new
product in many years. Apparently I'm not looking hard enough. Where
are all these 555's going?
8 pin DIPs were around in the 60s for linear products. Motorola
referred to them as their "Case 626" and used them for a lot of
consumer products such as the MC1350 IF amplifier. There was even a
4-pin DIP (Case 629) for the MFC4000 series of transistor arrays. The NE555 for analog-minded folks is a hugely useful
IC. Every
couple of months it seems that there's a circuit in EDN or Electronic
Design using one.
I've lately seen one used as a switching boost regulator. I've often
wondered if the NE555 (and 556) isn't the single most popular IC in
history.
The web site mentioned suggests that is so. I've been repairing some
modern stuff lately for friends (ipod, cell phone, laptop, digital
cameras) so I'm not completely stuck in dealing with hardware from the
past, but recent uses of the 555 have escaped me.
11:58 a.m.
New subject: DIP packages & the 555
On 9/23/10 2:49 PM, Brent Hilpert wrote:
The web site mentioned suggests that is so. I've
been repairing some
modern stuff lately for friends (ipod, cell phone, laptop, digital
cameras) so I'm not completely stuck in dealing with hardware from the
past, but recent uses of the 555 have escaped me.
They're just not much used in computers or "computery" things. (like
everything you mentioned above)
-Dave
--
Dave McGuire
Port Charlotte, FL
12:02 p.m.
New subject: DIP packages & the 555
On 9/23/10, Dave McGuire <mcguire at neurotica.com> wrote:
They're just not much used in computers or
"computery" things. (like
everything you mentioned above)
Lately, I'm sure that's true, but IIRC seeing them in the late 1970s
and early 1980s as timed one-shots on reset circuits on
microprocessors.
I only ever used them for audio noisemakers and LED blinkers until the
past year or two when I started dabbling in PWM. I read all I can
find about them and learn something every time I do - the on-chip
design may be simple, but the the applications are myriad and complex.
-ethan
11:51 a.m.
New subject: DIP packages & the 555
Ethan Dicks wrote:
On 9/23/10, Dave McGuire <mcguire at
neurotica.com> wrote:
They are still quite popular as they are common and cheap.
Its only recently that other more specialized devices have
edged them out. However it was a mainstay in power
supplies and are still see there and many other places.
They're just not much used in computers or
"computery" things. (like
everything you mentioned above)
Lately, I'm sure that's true, but IIRC seeing them in the late 1970s
and early 1980s as timed one-shots on reset circuits on
microprocessors.
I only ever used them for audio noisemakers and LED
blinkers until the
past year or two when I started dabbling in PWM. I read all I can
find about them and learn something every time I do - the on-chip
design may be simple, but the the applications are myriad and complex.
I've used them as system reset timers and sequencers, Power sequencers,
tone generators and sequential timing logic. Another use was
tone/frequency dividers. I've used them to pump up or invert power
bus voltages for low power analog use or drive transistors
and MOSFETs for high power voltage conversion. My favorite use is
window detector for saturation tape playback circuit.
It's one of those what can't you do with it parts.
Allison
-ethan
12:06 p.m.
New subject: DIP packages & the 555
On 9/23/10 3:02 PM, Ethan Dicks wrote:
Yep. I should've qualified my statement above to include the term
"modern".
They're just not much used in computers or "computery" things. (like
everything you mentioned above)
Lately, I'm sure that's true, but IIRC seeing them in the late 1970s
and early 1980s as timed one-shots on reset circuits on
microprocessors. I only ever used them for audio noisemakers and LED
blinkers until the
past year or two when I started dabbling in PWM. I read all I can
find about them and learn something every time I do - the on-chip
design may be simple, but the the applications are myriad and complex.
It really is an amazing circuit.
-Dave
--
Dave McGuire
Port Charlotte, FL
12:49 p.m.
New subject: DIP packages & the 555
On 2010 Sep 23, at 12:06 PM, Dave McGuire wrote:
On 9/23/10 3:02 PM, Ethan Dicks wrote:
I think my favorite observed application was a series of them used as
touch-sensitive switches for preset station selection in a mid-1970's
Sherwood FM tuner.
It was the type of app that might get mentioned in some book or article
as an idea, but not likely to be used in real-world production. I kind
of wonder how they stood up in those FM tuners in high-static
climates/environments.
I only ever used them for audio noisemakers and
LED blinkers until the
past year or two when I started dabbling in PWM. I read all I can
find about them and learn something every time I do - the on-chip
design may be simple, but the the applications are myriad and complex.
It really is an amazing circuit.
12:35 p.m.
New subject: DIP packages & the 555
On 2010 Sep 23, at 11:58 AM, Dave McGuire wrote:
On 9/23/10 2:49 PM, Brent Hilpert wrote:
No, I wouldn't expect to see them in those things, but, off the top of
my head, in the last couple of months I have also repaired for friends:
- water pump (microcontroller)
- simple valve control system
- jigsaw (not variable speed so I guess I just missed with that one)
- battery chargers (op amps and microcontrollers)
- a couple of switching power supplies in things like DVD players
Someday I expect somebody will throw a battery-powered drill at me to
repair - maybe then.
The web site mentioned suggests that is so.
I've been repairing some
modern stuff lately for friends (ipod, cell phone, laptop, digital
cameras) so I'm not completely stuck in dealing with hardware from the
past, but recent uses of the 555 have escaped me.
They're just not much used in computers or "computery" things.
(like everything you mentioned above)
12:04 p.m.
New subject: DIP packages & the 555
On 23 Sep 2010 at 11:49, Brent Hilpert wrote:
Cases 626 & 629 are not present in the 1969
Motorola Databook,
however.
From what I see the devices you mention are 70's products. In my
(limited) search the earliest mention or ref for use of the 8-pin I
have found is 1971 (the 555).
They are in my big brown 2nd edition 1969 moto databook. Go to the
section labeled "Consumer Products" and have a gander.
--Chuck
12:23 p.m.
New subject: DIP packages & the 555
On 2010 Sep 23, at 12:04 PM, Chuck Guzis wrote:
On 23 Sep 2010 at 11:49, Brent Hilpert wrote:
Curious, I have:
The Semiconductor Data Book
Motorola Semiconductor Products
4th Edition, June 1969
(on back cover):
4552 Printed in USA 7-69 WAK
(also big & brown)
I don't see a separate Consumer Products section, although the MC1303
stereo preamp and MC1325 chroma demodulator (the only 1300 series
devices listed) are present with the linear ICs. In the packaging
section the last case number listed is Case 620.
(?)
Cases 626 & 629 are not present in the 1969
Motorola Databook,
however.
From what I see the devices you mention are 70's products. In my
(limited) search the earliest mention or ref for use of the 8-pin I
have found is 1971 (the 555).
They are in my big brown 2nd edition 1969 moto databook. Go to the
section labeled "Consumer Products" and have a gander.
2:07 p.m.
New subject: DIP packages & the 555
On 23 Sep 2010 at 12:23, Brent Hilpert wrote:
I don't see a separate Consumer Products section,
although the MC1303
stereo preamp and MC1325 chroma demodulator (the only 1300 series
devices listed) are present with the linear ICs. In the packaging
section the last case number listed is Case 620.
Mine is a hard-cover "The Microelectronics Data Book"
Copyright (C) 1969
2nd Edition, December, 1969
About 2.25 inches thick. About 3 times the size of the 1968 edition.
Includes a section on MOS (MC1124L MC1141G, MC1150L, MC1151L) and
Memories (MC1036, MC1037, MC4004, MC4005) as well as a "Microwave
Device" section with the MCH5800 chip inductors and the MCH5880 chip
resistors).
--Chuck
3:09 p.m.
New subject: DIP packages & the 555
On 2010 Sep 23, at 2:07 PM, Chuck Guzis wrote:
On 23 Sep 2010 at 12:23, Brent Hilpert wrote:
I guess what I have is a 'full-line' catalog, it includes diodes and
transistors but only lists or has one-page entries (not full specs) for
ICs, while what you have is the more detailed specs and datasheets for
ICs.
Most, but not all, of the devices you mention are listed in the book I
have.
In any event, perhaps we have narrowed down the intro of the 8-pin DIP
to the latter half of 1969, for Motorola at least.
I don't see a separate Consumer Products
section, although the MC1303
stereo preamp and MC1325 chroma demodulator (the only 1300 series
devices listed) are present with the linear ICs. In the packaging
section the last case number listed is Case 620.
Mine is a hard-cover "The Microelectronics Data Book"
Copyright (C) 1969
2nd Edition, December, 1969
About 2.25 inches thick. About 3 times the size of the 1968 edition.
Includes a section on MOS (MC1124L MC1141G, MC1150L, MC1151L) and
Memories (MC1036, MC1037, MC4004, MC4005) as well as a "Microwave
Device" section with the MCH5800 chip inductors and the MCH5880 chip
resistors).
3:46 p.m.
New subject: DIP packages & the 555
On 23 Sep 2010 at 15:09, Brent Hilpert wrote:
In any event, perhaps we have narrowed down the intro
of the 8-pin DIP
to the latter half of 1969, for Motorola at least.
Seems reasonable to me.
The remarkable thing about Motorola's databooks from that time was
that they were lacking completely and utterly in page numbering. Not
even the appnote pages were numbered. The only way to find what you
were looking for in a section was to leaf through the pages one by
one.
Perhaps that was by design.
--Chuck
11:47 a.m.
New subject: DIP packages & the 555
On 2010 Sep 23, at 7:06 AM, Dave McGuire wrote:
A common use of 555s is as a PWM generator for large battery-powered
tools such as drills, power screwdrivers, and saws. These alone
account for quite a few 555s.
There was also one in my recently-replaced
dishwasher (built around
2000) that timed one of the cycles. I think this was one of the few
times I actually saw a 555 used as a "timer". ;)
OK, interesting to know. I often repair household stuff for friends but
I guess just as a matter of chance/coincidence haven't come across one
in newer stuff.
I designed 555s into a commercial product in 2002
and again in 2004.
I needed a ~455KHz carrier generator for an IR data transmitter, and
a 555 was the easiest way to do it.
21 Sep
21 Sep
1:34 p.m.
Also, Eric Kudzin spent some time trying to fix the
CRT, we are making
progress and as part of the testing we need to test a KNOWN WORKING
computer on the Alto monitor/crt. I have a PET 2001, we made a custom
cable (it "should" work), anyone know if the PET video out will work on
the Alto monitor?
Since the Alto is a grpahics workstation with a fairly high resolution (I
assume), I would guess the horizotnal scan rate of the monitor was much
higher than the 15kHz used by the PET. In other words, I don't think it's
going to work.
Can you not use a 'scope or logic analuser to check that the Alto is
giving out sync pulses and some kind of video? If it is, then you can use
that to test the monitor.
-tony
11:29 p.m.
On 2010 Sep 20, at 9:16 PM, Nick Allen wrote:
Need to find the 14 pin opamp (as I am also a purest
and want it to
be ORIGINAL), found a pair on ebay:
http://cgi.ebay.com/ws/eBayISAPI.dll?
ViewItem&item=330471900022&rvr_id=143156802920&crlp=1_263602_263622&UA=
%3F*F%3F&GUID=94213f4c1260a0269d971e47ff8e9d4d&itemid=330471900022%24&f
f4=263602_263622
WAY to expensive, and I only need 1, anyone have one they might be
able to sell me, or able to find a cheaper source?
http://lh6.ggpht.com/_lkddKjPsPFU/TJgv61uSNMI/AAAAAAAABhM/-n0SEds-o5g/
_1020935.JPG
With a blown 709 to replace, you might find this interesting, an
interview with Dave Fullagar, the designer of the 741, following 709
designer Bob Widlar's departure from Fairchild:
http://www.edn.com/article/472246-
Voices_Dave_Fullagar_analog_IC_designer_and_entrepreneur.php
Extract:
My assigned task when I joined Fairchild R&D in 1966 was to design
the successor to the ?A709.
...
However the biggest problems with the 709 were its idiosyncrasies,
not its specifications:
It was tricky to stabilize, there was no short-circuit protection,
and it would latch-up and
self-destruct in nanoseconds.
...
--
If op-amp history is too off-topic for people, there is also some
mention of the development of those nifty Maxim RS232 drivers.
13 Sep
13 Sep
5:20 p.m.
On 9/12/10 5:00 PM, Ian King wrote:
drive, but +5V is only measuring at
around 2.5V. The lamps on the front of the drive do
not light-up, and
the LOAD/RUN button does nothing, hence the door lock does not unlock.
Here is a link to the video: http://www.youtube.com/watch?v=mx80CvjuvyE
OK.. just watched the video. The CPU is fine. The red button disables the
servo in the drive. His 5v is hosed in the drive, not the CPU.
He originally reported that he smelled
something burning in the drive, so I assume the low voltage supply inside
is toast. 5v is derived from the incoming +15.
It also appears to be a file server machine. It has the 80/300mb disc control
in the bottom, which is what all the colored ribbon cables are down there in
the CPU.
14 Sep
14 Sep
6:20 a.m.
Al,
Do you know which board/component inside the Alto creates 5V from
the incoming 15V? If you can describe it in detail, it will help me
immensely (so I can diagnose the failed component).
11:07 a.m.
On 9/14/10 6:20 AM, Nick Allen wrote:
Al,
Do you know which board/component inside the Alto creates 5V from the incoming 15V?
It is documented in the service manual. One of the PC boards has everything for the
regulator
except the pass transistors, which are on the heat sink on the back.
1:38 p.m.
Al,
Do you know which board/component inside the Alto creates 5V from
the incoming 15V? If you can describe it in detail, it will help me
immensely (so I can diagnose the failed component).
I beleive it's a circuit (more than one component is involved) inside the
Diablo drive. Certainly the Model 30s I used on a PDP11 only took +/-15V
from the PSU.
You need to get the service manual for the deive (Eric Smith suggested
there's something of use on bitsavers) and see how the 5V is produced.
Note that the fault may well not be in that section. It's entirely
possible for excessive loading (say a very leay capacitor) to pull the
output of the regualtor cirucit down so that it can't supply 5V properly.
Before you start replacing parts you, as ever, need to do some tests
(Yes, I know this is not the way it's done these days, but it's the way i
do it, and it's never failed me...)
-tony
15 Sep
15 Sep
8:42 a.m.
Thanks EVERYONE for all your help and suggestions! Armed with the
schematics recommended, I will begin to troubleshoot, hopefully I can
get some assistance and expertise during the Midwest Vintage Computer
Festival this Saturday!!!
10:07 a.m.
On 9/15/10, Nick Allen <nick.allen at comcast.net> wrote:
Thanks EVERYONE for all your help and suggestions!
Armed with the
schematics recommended, I will begin to troubleshoot, hopefully I can
get some assistance and expertise during the Midwest Vintage Computer
Festival this Saturday!!!
See you there! (I've never seen an Alto up close)
-ethan
10:50 a.m.
New subject: DEC PDP spare boards & backplane for sale on ebay
Just listed some spare DEC PDP parts on ebay, I haven't had much use
for them, hopefully they will find a good home!
DEC PDP G227, G619, G104 Core Memory 4k Words Board
<http://cgi.ebay.com/DEC-PDP-G227-G619-G104-Core-Memory-4k-Words-Board-/270635762364?pt=LH_DefaultDomain_0&hash=item3f032602bc>:
http://cgi.ebay.com/DEC-PDP-G227-G619-G104-Core-Memory-4k-Words-Board-/2706…
DEC PDP G918 fc photo amplifier Board
<http://cgi.ebay.com/DEC-PDP-G918-fc-photo-amplifier-Board-/270635763952?pt=LH_DefaultDomain_0&hash=item3f032608f0>:
http://cgi.ebay.com/DEC-PDP-G918-fc-photo-amplifier-Board-/270635763952?pt=…
DEC PDP G930 Board
<http://cgi.ebay.com/DEC-PDP-G930-Board-/270635765207?pt=LH_DefaultDomain_0&hash=item3f03260dd7>:
http://cgi.ebay.com/DEC-PDP-G930-Board-/270635765207?pt=LH_DefaultDomain_0&…
DEC PDP M8330 KK8E - Timing board
<http://cgi.ebay.com/DEC-PDP-M8330-KK8E-Timing-board-/270635766119?pt=LH_DefaultDomain_0&hash=item3f03261167>:
http://cgi.ebay.com/DEC-PDP-M8330-KK8E-Timing-board-/270635766119?pt=LH_Def…
DEC PDP M8350 KA8E External positive I/O bus interface
<http://cgi.ebay.com/DEC-PDP-M8350-KA8E-External-positive-I-O-bus-interface-/270635766749?pt=LH_DefaultDomain_0&hash=item3f032613dd>:
http://cgi.ebay.com/DEC-PDP-M8350-KA8E-External-positive-I-O-bus-interface-…
DEC PDP W940 IC Board
<http://cgi.ebay.com/DEC-PDP-W940-IC-Board-/270635767858?pt=LH_DefaultDomain_0&hash=item3f03261832>:
http://cgi.ebay.com/DEC-PDP-W940-IC-Board-/270635767858?pt=LH_DefaultDomain…
DEC PDP W990 IC Board
<http://cgi.ebay.com/DEC-PDP-W990-IC-Board-/270635768387?pt=LH_DefaultDomain_0&hash=item3f03261a43>:
http://cgi.ebay.com/DEC-PDP-W990-IC-Board-/270635768387?pt=LH_DefaultDomain…
DEC PDP Omnibus 10 slot Backplane
<http://cgi.ebay.com/DEC-PDP-Omnibus-10-slot-Backplane-/270635769866?pt=LH_DefaultDomain_0&hash=item3f0326200a>http://cgi.ebay.com/DEC-PDP-Omnibus-10-slot-Backplane-/270635769866?pt=LH_DefaultDomain_0&hash=item3f0326200a
11:34 a.m.
New subject: DEC PDP spare boards & backplane for sale on ebay
I got one PDP8E lacking of some of these boards.
Sergio
2010/9/15 Nick Allen <nick.allen at comcast.net>
Just listed some spare DEC PDP parts on ebay, I
haven't had much use for
them, hopefully they will find a good home!
DEC PDP G227, G619, G104 Core Memory 4k Words Board <
http://cgi.ebay.com/DEC-PDP-G227-G619-G104-Core-Memory-4k-Words-Board-/2706…2bc>:
http://cgi.ebay.com/DEC-PDP-G227-G619-G104-Core-Memory-4k-Words-Board-/2706…
DEC PDP G918 fc photo amplifier Board <
http://cgi.ebay.com/DEC-PDP-G918-fc-photo-amplifier-Board-/270635763952?pt=…8f0>:
http://cgi.ebay.com/DEC-PDP-G918-fc-photo-amplifier-Board-/270635763952?pt=…
DEC PDP G930 Board <
http://cgi.ebay.com/DEC-PDP-G930-Board-/270635765207?pt=LH_DefaultDomain_0&…dd7>:
http://cgi.ebay.com/DEC-PDP-G930-Board-/270635765207?pt=LH_DefaultDomain_0&…
DEC PDP M8330 KK8E - Timing board <
http://cgi.ebay.com/DEC-PDP-M8330-KK8E-Timing-board-/270635766119?pt=LH_Def…167>:
http://cgi.ebay.com/DEC-PDP-M8330-KK8E-Timing-board-/270635766119?pt=LH_Def…
DEC PDP M8350 KA8E External positive I/O bus interface <
http://cgi.ebay.com/DEC-PDP-M8350-KA8E-External-positive-I-O-bus-interface-…3dd>:
http://cgi.ebay.com/DEC-PDP-M8350-KA8E-External-positive-I-O-bus-interface-…
DEC PDP W940 IC Board <
http://cgi.ebay.com/DEC-PDP-W940-IC-Board-/270635767858?pt=LH_DefaultDomain…832>:
http://cgi.ebay.com/DEC-PDP-W940-IC-Board-/270635767858?pt=LH_DefaultDomain…
DEC PDP W990 IC Board <
http://cgi.ebay.com/DEC-PDP-W990-IC-Board-/270635768387?pt=LH_DefaultDomain…a43>:
http://cgi.ebay.com/DEC-PDP-W990-IC-Board-/270635768387?pt=LH_DefaultDomain…
DEC PDP Omnibus 10 slot Backplane <
http://cgi.ebay.com/DEC-PDP-Omnibus-10-slot-Backplane-/270635769866?pt=LH_D…
http://cgi.ebay.com/DEC-PDP-Omnibus-10-slot-Backplane-/270635769866?pt=LH_D…
2 p.m.
New subject: DEC PDP spare boards & backplane for sale on ebay
2010/9/15 Nick Allen <nick.allen at
comcast.net>
> Just listed some spare DEC PDP parts on ebay, I haven't had much use for
> them, hopefully they will find a good home!
I wish I'd known - I see you are in Chicago, and I'm coming to VCFmw.
I have an -8/e that I'm restoring. The M8330 might come in handy (I
have an older rev one, an M833, that is supposed to only work with 4K
TTY machines)
-ethan
12:10 p.m.
On Wed, Sep 15, 2010 at 12:07 PM, Ethan Dicks <ethan.dicks at gmail.com> wrote:
See you there! ?(I've never seen an Alto up close)
Certainly not outside a museum. CHM probably has one/many, and I know
I saw one at the Smithsonian's exhibit, which was partially closed at
the time but I snuck a peek behind the curtains and there was the
Alto :)
--
jht
13 Sep
13 Sep
1:26 p.m.
I thought a video might be easier for you all to see the issue I am
having with restoring my Xerox Alto.
The issue I am having is the Diablo Disk drive does not power on fully
(I am measuring +15 and -15V on the drive, but +5V is only measuring at
around 2.5V. The lamps on the front of the drive do not light-up, and
the LOAD/RUN button does nothing, hence the door lock does not unlock.
I don't know the Alto at all, but this sounds a bit like a Diablo model
30 drive. In it?
If so, from whta I remember, it derrives the +5V rail intenrally from the
+15V supply. If the +5V rail is low, then either there's a problem in the
regulator, or an overcurrnet condition (maybe a nearly-shorted
capacitor).
FWIW, I have the DIablo Model 30 service mnaual, but it woudl take a
little time to find it.
Here is a link to the video: http://www.youtube.com/watch?v=mx80CvjuvyE
I have visually inspected all PCB boards and components, nothing seem to
be damaged. Also, the power supplies seem to be outputting power
properly (as seen via the RED voltage LEDS in the Alto card cage.
I would still chekc thiem with a voltmeter and a 'scope (to look for
excessive ripple).
Any recommendations on how to troubleshoot the disk
drive further?
-tony
5:03 p.m.
Tony Duell wrote:
I don't know the Alto at all, but this sounds a
bit like a Diablo model
30 drive. In it?
Most Altos have the Diablo 31 (a variant of the 30 family). Some have
the Diablo 44.
FWIW, I have the DIablo Model 30 service mnaual, but
it woudl take a
little time to find it.
Bitsavers has some 30-series and 40-series maintenance documentation online:
http://bitsavers.org/pdf/diablo/
4983
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4999
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101 comments
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