Date   
Re: HP App Notes 201-X series wanted

 

Hey Mr Wise-A**, no such thing. That's the whole note (Jack's joke was referring to a program named HARPO in the note).
Marc

Re: HP App Notes 201-X series wanted

Jack Rubin
 

Thanks Marc (for the scan) and Steve (for the implementation). A quick read through the manual raises questions about the missing routines, GROUCHO and ZEPPO. Is there another chapter in this volume?
--
Jack
www.computerarium.org

Re: HP App Notes 201-X series wanted

Steve Leibson
 

Hi Marc,

Yes, half of the words in the System Programming ROM are devoted to the Store(A$) command. It was the only way to get a listing back into the machine from a saved ASCII printout. I never imagined that the Loveland Instrument Division would use it to programmatically combine HPL program subroutines into completed ATE programs, but it proved very popular for them. It seemed so simple: just jam a line into the keyboard buffer and smack the "store" key with a JSR call. But there were several exceptions to the ASCII program listings compared to the stored program and all of the exception checking ended up consuming half of the ROM.

Chris Christopher was in charge of the HP 9825 firmware effort and he was not at all pleased with my tinkering. He was afraid my abuse of the 9825's live keyboard feature would surface a latent bug in the main language ROM and so he repeatedly told me "Any bugs you find are yours!" None were found, until the 9825S/T conversion turned up a latent bug in my own code, but not in the Store(A$) command. It was in one of the special 98036A register-access commands I'd added. There were two writes misdirected at ROM locations. In the 9825A/B, writes to a ROM address counted as NOPs, so no damage was done. In the 9825S/T with full 16-bit addressing, RAM occupied those locations and the conversion team had to debug the problem of two RAM locations being mysteriously zeroed out for no apparent reason. "Any bugs you find are yours!" is what I told the conversion team. "It works fine on the 9825A/B."

By the way, the Systems Programming ROM was my first and only commercial software-only product. That's how we did it back then at HP. Design and debug hardware one day, run a lathe or mill the next day (under close supervision by the machinists who hated having engineers fooling with a power tool), write code the day after. What's all this specialization stuff?

--Steve


On 1/23/2020 5:03 PM, CuriousMarc wrote:
Just added my scan of the missing AN 201-06 Computer Communications HP 9825 - HP 1000. One is a large (45 MB) pdf file with high resolution scan, the other one is a smaller (4.5MB) one with searchable text. They describe communication over HP-IB and Serial, with ways to upload and download program and data from the 9825 to the HP 1000 running FORTRAN helper programs. It can be done, but pretty contrived as expected, I suspect not many people went through the trouble. It uses Steve Leibson's system programming feature "store" command to download programs (Steve did I get this right that you put that function in?). Many thanks to John Lawson for a) rescuing the manual and b) driving it all the way from Nevada to California. Now that's customer service!
Marc
-- 
Steve Leibson

Phone (Cell): 408-910-5992
Phone (Home): 408-292-4930


Please feel free to link to me on LinkedIn


History site: www.hp9825.com

#Iwork4Intel

Re: HP App Notes 201-X series wanted

 

Just added my scan of the missing AN 201-06 Computer Communications HP 9825 - HP 1000. One is a large (45 MB) pdf file with high resolution scan, the other one is a smaller (4.5MB) one with searchable text. They describe communication over HP-IB and Serial, with ways to upload and download program and data from the 9825 to the HP 1000 running FORTRAN helper programs. It can be done, but pretty contrived as expected, I suspect not many people went through the trouble. It uses Steve Leibson's system programming feature "store" command to download programs (Steve did I get this right that you put that function in?). Many thanks to John Lawson for a) rescuing the manual and b) driving it all the way from Nevada to California. Now that's customer service!
Marc

New files uploaded to VintHPcom@groups.io

VintHPcom@groups.io Notification <VintHPcom+notification@...>
 

Hello,

This email message is a notification to let you know that the following files have been uploaded to the Files area of the VintHPcom@groups.io group.

Uploaded By: CuriousMarc <marc.verdiell@...>

Description:
AN 206-01 HP 9825 to HP 1000 Communications

Cheers,
The Groups.io Team

Re: HP9030a repair with new ROM card

Anders
 

Nice! Looking forward to the next one in the series.

Re: HP9826/36 PowerFail option RTC?

Anders
 

Still working on this. I skipped the idea t keep the 98x6 time value in the RTC. It is an ieee real, 64 bits that the DS2417 is 32 bits, but that is no real problem and besides is it far easier to read two integers. I will just decide on an arbitrary zero date. In my case jan 1 2000 and when I set the time I subtract that from the TIMEDATE and write the result as two integers. When reading I do the opposite, read the two integers, combine and add my zero date.

Code is ready, but I seem to have misplaced the three DS2417's I bought three years ago. Easily done as they are really small...

HP9030a repair with new ROM card

jerryw <jerry@...>
 

Hi all
I am new to this forum and I am finding reading the threads very interesting.
I repair and restore vintage computer and have recently started creating Youtube videos showing these.
Recently I repaired an HP9830a and this turned out to be an epic repair and I ended up having to design a new ROM card as the original had failed.
Over 100 failed IC's
For anyone interested here is the first video https://www.youtube.com/watch?v=LweofUSLSRo
There is also a video list for this series.
I am about to repair two more 9830a's and I need some key caps if anyone has any.

Re: Weak 9872CT Plotter Platen

Martin Hepperle
 

Here are some more measurements. 
 
Using my simple Uni-T 61B, max. 600V, 10MΩ impedance
measurements against ground (cathode of CR102)
  • cathode of CR103:   +474V
  • anode of CR102,102: -288V
  • anode of CR101:     -465V
  • calculated: from cathode CR103 to anode CR 101: +474V - (-465V) = 939V
  • before L101: 34.7V
  • behind L101: 34.0V
 
 
Using HP 3456A, max. 1000V, 10MΩ impedance
  • across cathode of CR103 to anode of CR101: 934V
    [that is: before passing through R105+R106, R102+R103 (1.8 MOhm each)]
  • across J101 (platen connected): 533V
  • across J101 (platen disconnected): 514V
    [that is: after passing through R105+R106, R102+R103 (1.8 MOhm each)]
 

Re: Weak 9872CT Plotter Platen

Paul Berger
 

Martin,

The reference being slightly higher would only mean the high voltage would be a bit higher.  The fact that you see 5.2 volts at the - input of U102 would suggest that there is high voltage since it is fed by a voltage divider with approximately 90 to 1 ratio . What do you get at the cathode of CR103?  What sort of a meter are you using?  If it is a digital meter they usually have an input impedance of 10M especially on the higher voltage ranges.

Paul.

On 2020-01-22 6:53 a.m., Martin Hepperle wrote:
Thank you all for your comments and hints. I guess my test equipment is not perfect for these tests and now I am not sure that the platen itself is the problem.

I measured the voltages going into the comparator/op-amp U102.
a: UREF 5V is actually 5.21V in my case (measured at right side of R119)
b: behind R119, at (+) of U102 I see 5.04V (measured at left side of R119)
c: between R109 and R110, at (-) of U102 I see 5.20 V (measured at left side of R109)
(right and left as seen from the rear of the open plotter)

My plan is now to first correct UREF to be closer to 5V. In fact this may be my fault as I replaced the broken 4.99V Zener VR12 on the main PSU board by a 5.1V Zener because I did not have a 4.99V at hand. I believed that with the tolerances this might be o.k. but just believing is only an alternative fact ... So I'll order some 4.9 and 5.0 V Zeners to see what happens .next.

Martin

Re: Weak 9872CT Plotter Platen

Martin Hepperle
 

Thank you all for your comments and hints. I guess my test equipment is not perfect for these tests and now I am not sure that the platen itself is the problem.

I measured the voltages going into the comparator/op-amp U102.
a: UREF 5V is actually 5.21V in my case (measured at right side of R119)
b: behind R119, at (+) of U102 I see 5.04V (measured at left side of R119)
c: between R109 and R110, at (-) of U102 I see 5.20 V (measured at left side of R109)
(right and left as seen from the rear of the open plotter)

My plan is now to first correct UREF to be closer to 5V. In fact this may be my fault as I replaced the broken 4.99V Zener VR12 on the main PSU board by a 5.1V Zener because I did not have a 4.99V at hand. I believed that with the tolerances this might be o.k. but just believing is only an alternative fact ... So I'll order some 4.9 and 5.0 V Zeners to see what happens .next.

Martin

Re: Weak 9872CT Plotter Platen

yann Minder
 

Hello, do not forget your voltmeter input impedance forms a voltage divider with the high value resistors at the votage multiplier output. Different models will show different results...

yann




On Wed, Jan 22, 2020 at 4:16 AM +0100, "Paul Berger" <phb.hfx@...> wrote:

One thing I might add is you might want to measure the voltage at the 
cathode of CR103 to ground or disconnect the platen for the first try.  
There are very large resistors in series with the connections to the 
platen, and if some contamination happened to get in through the damage, 
it would not take much to pull down the voltage at the platen.

Paul.

On 2020-01-21 10:13 p.m., Craig Ruff wrote:
> I can confirm what Paul said about the circuit. I get 525 V when the chart hold is activated with good adhesion of the paper.
> 
>



Re: Weak 9872CT Plotter Platen

Paul Berger
 

One thing I might add is you might want to measure the voltage at the cathode of CR103 to ground or disconnect the platen for the first try.  There are very large resistors in series with the connections to the platen, and if some contamination happened to get in through the damage, it would not take much to pull down the voltage at the platen.

Paul.

On 2020-01-21 10:13 p.m., Craig Ruff wrote:
I can confirm what Paul said about the circuit. I get 525 V when the chart hold is activated with good adhesion of the paper.

Re: Weak 9872CT Plotter Platen

 

I can confirm what Paul said about the circuit. I get 525 V when the chart hold is activated with good adhesion of the paper.

Wanted: original CS/80 Instruction Set Programming Manual. HP 5955-3442

Guy Dunphy
 

In gathering info on the HP CS/80 command set, I've found most of what I want
including a PDF of:
CS/80 Instruction Set Programming Manual. HP 5955-3442 Apr 1983

But I'd really like to obtain an original printed copy of that. For one thing it
deserves a better quality scan than that PDF.

Does anyone have an original paper copy they'd sell?

Guy

Re: Weak 9872CT Plotter Platen

Kuba Ober
 

Aaah. Now that’s something I did not realize: this is an interdigitated electrostatic platen. The one I saw a while ago was a continuous electrode, not two interleaved ones. I have to think of what does this bring to in possible troubleshooting. – Kuba

20 jan. 2020 kl. 8:32 fm skrev Martin Hepperle <Martin.Hepperle@...>:

... schematics in true size + platen schema
<9872CT-Chart-PSU-Schematics.png>
<9872CT-Platen.pdf>

Re: Disk selector switch for a disk emulator?

Anders
 

On Mon, Jan 20, 2020 at 03:07 PM, Martin Hepperle wrote:
change the disk geometry on the fly.
For now, I have the same for all disks, but that is certainly something I can look at.

Re: Disk selector switch for a disk emulator?

Anders
 

I have gotten a lot of good tips here! Keep them coming! Remember that most of the units so far has been used with various types of HP Measuring instruments, SA's, VNA's etc where there is little or no need for multiple disks.

For an instrument, a small unit that plugs into the back of the instrument is preferable. For an emulator to be used with a computer, then perhaps a much larger box that sits beside the unit is OK.

I would very much like the software to be backward compatible so that people who have bought my PCB can enjoy the developments I make.

Can someone suggest a small LCD, either SPI och I2C? Perhaps just one-line, but one that will fit in a small box like the one below?

Re: Weak 9872CT Plotter Platen

Paul Berger
 

Opoops I meant to change my statement about "A" it should be steady near 5V as long as pin 2 of U102 is less than pin 3. 


On 2020-01-20 11:18 a.m., Paul Berger via Groups.Io wrote:

Martin,

At "A" I would expect 5V pulses as long as the voltage on pin 2 of U102 is less than 5V.

At "B" you should see +34V

What you will see at "C" would depend on the state of chart hold, if chart hold is off then "C" will be around 34V if chart hold is on then it should be pulsed.

It would appear that when chart hold is off pin 4 of U103 should be low and pin 6 would go to open (7406 has open collector outputs) this would inhibit Q101 which is the switch transistor.  When chart hold is on, pin 4 should go to open state and allow the 20 KHz   to reach pin 5 which would cause the output to switch at a 20KHz rate and in turn "C" would be pulsed at that rate as long as the base of Q101 is positive (around +5V) this is controlled by Q102 that has its collector tied to +5V the base Q102 should be positive and turn on Q102 as long as the voltage on pin 2 of U102 is less than pin 3.  Pin 3 of U102 is tied to a +5 reference voltage and should be very close to 5V.

In your picture U102 does not have a manufacturers logo on it and I cannot find that part number in any cross reference I have so perhaps it is a custom HP made part but in this application it is likely to be an op-amp or a comparator.  Is the 50V above C108 the voltage rating of C108? and is the supply voltage to pin 7 of U102 correct?

Paul.


On 2020-01-20 9:22 a.m., Martin Hepperle wrote:
Some update: I made some test with aluminum foil but the result was similar to paper - not enough suction.
I also washed the platen as well as the high voltage PCB with a PCB cleaner and Isopropanol to make sure no dirt conducts my valuable electricity away.

Mine is the "C" versions of this plotter (9872/7720) which has a different schematics that the "A" model shown by Rik.
I am not sure what I should expect at points (A), (B), (C).
I could not find a replacement type for U102, the HP number does not appear in my X-Ref lists.

Here is the relevant part (with my blue scribbling on top, check marks indicate that I desoldered one side of the component to test it):




Re: Weak 9872CT Plotter Platen

Paul Berger
 

Martin,

At "A" I would expect 5V pulses as long as the voltage on pin 2 of U102 is less than 5V.

At "B" you should see +34V

What you will see at "C" would depend on the state of chart hold, if chart hold is off then "C" will be around 34V if chart hold is on then it should be pulsed.

It would appear that when chart hold is off pin 4 of U103 should be low and pin 6 would go to open (7406 has open collector outputs) this would inhibit Q101 which is the switch transistor.  When chart hold is on, pin 4 should go to open state and allow the 20 KHz   to reach pin 5 which would cause the output to switch at a 20KHz rate and in turn "C" would be pulsed at that rate as long as the base of Q101 is positive (around +5V) this is controlled by Q102 that has its collector tied to +5V the base Q102 should be positive and turn on Q102 as long as the voltage on pin 2 of U102 is less than pin 3.  Pin 3 of U102 is tied to a +5 reference voltage and should be very close to 5V.

In your picture U102 does not have a manufacturers logo on it and I cannot find that part number in any cross reference I have so perhaps it is a custom HP made part but in this application it is likely to be an op-amp or a comparator.  Is the 50V above C108 the voltage rating of C108? and is the supply voltage to pin 7 of U102 correct?

Paul.


On 2020-01-20 9:22 a.m., Martin Hepperle wrote:
Some update: I made some test with aluminum foil but the result was similar to paper - not enough suction.
I also washed the platen as well as the high voltage PCB with a PCB cleaner and Isopropanol to make sure no dirt conducts my valuable electricity away.

Mine is the "C" versions of this plotter (9872/7720) which has a different schematics that the "A" model shown by Rik.
I am not sure what I should expect at points (A), (B), (C).
I could not find a replacement type for U102, the HP number does not appear in my X-Ref lists.

Here is the relevant part (with my blue scribbling on top, check marks indicate that I desoldered one side of the component to test it):