Date   

Re: HP 9821 - display and tape transport issues #VintageHPComputers

Lee A. White
 

In the late 70's N S came out with a processor series designated as COPS (control oriented processor series). The company I worked for at the time had major field problems with controls using this processor - they were locking up in use. The problem was traced to extreme processor noise sensitivity. When operating next to electrically noisy equipment (like the magnetic contactor turning on a refrigeration compressor motor), the processor would see an instantaneous DC input voltage below the required "power supply good" voltage and the processor would halt. When the voltage rose back above the required "power good voltage" the processor would start an on chip start up timer and would then start the power on preset routines clearing memory, resetting the program counter,  etc.. When the on chip start up timer timed out the processor would be released to begin program execution. Problem was that the transient low voltage did not exist long enough for the on chip timer to discharge, so when the power returned to a valid level after the noise transient passed, the on chip timer had not yet fully discharged. As a result, it would time out too quickly and the processor would be released to execute program code before the power on preset routines had completed. The processor was then executing garbage and would lock up.
 
National was NO HELP AT ALL, denying that there could be anything wrong with their processors. After many calls and my getting very insistent, they challenged me to come out and prove it - to make it happen in their lab. On arrival I was shuttled off to a low level technician who was obviously supposed to humor me and then get rid of me. The welcoming was neither appreciative or respectful. I was clearly a PITA that they had no time for.
 
The tech took me to a test bench and watched as I set up the simple demo - the control with the processor in it and a compressor motor contactor set up to self cycle next to it. He connected some monitoring equipment to the processor and then turned everything on. In less than a minute the processor chip was locked up. The tech disappeared and returned with an engineer and it happened again. He got some more fresh parts - they all quickly locked up too. The engineer disappeared and returned with the engineering manager who saw it for himself and he then disappeared and returned with the VP - who was not happy. The VP suggested we try other processors in the series, and they all locked up too. It was now clear National had a design problem in the entire series that was going to require a mask change and cause a production interruption. Then the president/founder showed up and watched a processor lock up and then no one was happy. He asked if they could keep the test setup, and I happily agreed. Everyone was told to meet in a conference room in five minutes and I was asked to leave - escorted to the door actually. I didn't even get a lunch out of it.
 
National never replaced the bad parts in our inventory, nor did they do anything to make up for the bad product we had in the field or the costs of the field problems. They never said thank you either, nor did they make their problem known to other customers.
 
Care to guess how much respect I have for National Semiconductor.
 
A Japanese company got all our future mask programmable micro processor business - and we were a very big player in the automotive, appliance, and  heating and air conditioning controls businesses - what they call a tier one OEM supplier.
 
 
 

From: Rik Bos
Sent: Monday, February 03, 2020 3:27 PM
Subject: Re: [VintHPcom] HP 9821 - display and tape transport issues #VintageHPComputers

I think you missed an email, I mistook NI for NS.
I use NI software for design and simulation and am happy with it. I'm not happy with National Semiconductor logic IC's from the early 70th era.

-Rik

-Rik




On Mon, Feb 3, 2020 at 9:19 PM +0100, "Steve Leibson" <steven.leibson@...> wrote:

Hard to square your views of National Instruments with the 4000 to 5000 screaming fans I saw annually at NI Week in Austin. I'm sorry you seem to have gotten bad treatment from them, but my mileage definitely varied over the span of 35 years.

--Steve


On Monday, February 3, 2020, 12:07:20 PM PST, <mariuszmleczko@...> wrote:


RIK: "A lot of transport problems are caused by a bad working EOT sensor, the LDR’s used in the system to detect the end of tape deteriorate and the resistance changes permanent to a low value."

I did a quick and very simple test. It is possible to run LDF, MRK, REW commands etc. with the opened cassete deck (without tape)....if at the same time top-right "cassette presence sensor" is pressed.
So I started it this way, trying to blink into a sensor by a pretty strong phone LED lighter, and.........no reaction.

Of corse I'm going
disassemble and measure EOT resistance anyway, but think also - if it was OK (and it's logic), then should be some reaction on my simple test.


Re: HP 4955A in Good Shape-- HPIB Interface for storing Basic Programs to a Modern Machine, possibly using HPDrive software over HPIB?

 

On Feb 20, 2020, at 3:22 PM, greg.linder@gmail.com wrote:

I recently picked up an HP 4955A Protocol Analyzer. Although my bench is stacked with HP vintage test equipment in daily use, this is my first fun foray into the world of pre-90's HP computing. I picked this up because it's apparently an HP9825 inside, and the one I have has the Basic option.
Do you mean the 9831? Same basic hardware, slightly different keys and ROMs to handle the Basic language.

There was another thread here about HP9825 mass storage options, and there was some question as to whether or not the HPDrive project works with this era of machine.
hpmuseum.net has some text saying this is possible, I do not have a 9831 so I can't vouch for that. You'd need the 98034 HP-IB interface obviously. However www.hp9831.com does not have any mention of being able to use an HP-IB interface.


HP 4955A in Good Shape-- HPIB Interface for storing Basic Programs to a Modern Machine, possibly using HPDrive software over HPIB?

greg.linder@...
 

Greetings, all:

I recently picked up an HP 4955A Protocol Analyzer. Although my bench is stacked with HP vintage test equipment in daily use, this is my first fun foray into the world of pre-90's HP computing. I picked this up because it's apparently an HP9825 inside, and the one I have has the Basic option. It powers up with some errors, but upon plugging in one of the pods, the Basic interpreter runs fine. It's in very good shape, considering it was in a garage for who knows how long.

That being said, I'd like to use this to have some fun writing basic programs, and maybe use it to control some of my other HP-IB stuff floating around in here.

My standard concern is the Tape Drives that have been discussed elsewhere. The unit needs to have its tape drives rebuilt, and then there's the questions of media, and all the rest. There was another thread here about HP9825 mass storage options, and there was some question as to whether or not the HPDrive project works with this era of machine. Before I dive into trying to figure this out, I wonder if this is the Best Way to move forward with this. Even more, does HPDrive have a hope of working with this HP 4955A, which is apparently based on the 9825 internals, but a slightly different beast when it comes to programming and such?

I've got some of the original paper manuals, some of which are marked as "preliminary". I'd love to find the service manual for this as well, but my standard haunts at the BAMA archive and other places have revealed nothing for the service manual, aside from buying a million pounds of paper on Ebay. It's a lovely machine, and I'd like to clean it up, fix the failures that show up on startup, and possibly make some good use of this. It's a very satisfying machine, and the Basic it comes with is very.. Complete and intuitive. Would it be worth me buying an Ebay manual and scanning it into BAMA, or does someone know of a PDF copy that exists somewhere?

Cheers,
-Greg Linder


Re: HP 9821 - display and tape transport issues #VintageHPComputers

mariuszmleczko@...
 

Yes, short time solution for quick testing of other tape functions before new LDR will come.


Re: HP 9821 - display and tape transport issues #VintageHPComputers

 

Using the old ldr isn't a good idea, the ldr will degrade more over time. At the best it will be a short time solution. I think the 5616 should work.

-Rik




On Wed, Feb 19, 2020 at 8:04 PM +0100, <mariuszmleczko@...> wrote:

Code: GL5616D
Diameter: 5mm
Light resistance:       
- 10lx - 5÷150 kΩ
- 100lx - < 2 kΩ
Dark resistance: 1 MΩ
Power: 100mW
Maximum voltage: 150V DC
Wave length: 540nm
Working temperature: -30°C ÷ +70°C

Will that be OK ? I'm not sure which 10lx or 100lx value take into account for light resistance condition.

Do you you think is it good idea to do a testing of existing LDR by adding ~13K resistor to it ? In a dark condition it shall give more than 19k which is more than 18k barrier.


Re: HP 9821 - display and tape transport issues #VintageHPComputers

mariuszmleczko@...
 

Code: GL5616D
Diameter: 5mm
Light resistance:       
- 10lx - 5÷150 kΩ
- 100lx - < 2 kΩ
Dark resistance: 1 MΩ
Power: 100mW
Maximum voltage: 150V DC
Wave length: 540nm
Working temperature: -30°C ÷ +70°C

Will that be OK ? I'm not sure which 10lx or 100lx value take into account for light resistance condition.

Do you you think is it good idea to do a testing of existing LDR by adding ~13K resistor to it ? In a dark condition it shall give more than 19k which is more than 18k barrier.


Re: Disk selector switch for a disk emulator?

Anders
 

I have breadboarded the design. One small 2x16 LCD, backlit, three switches: up, down, enter. Up and down scrolls through the available files. Enter selects the selected "disk" file. Thought I'd make a small piggyback board that fits the end of the current board at right angle. That way the original PCB can sit in an aluminium box and the piggyback board sit behind the front panel.


Re: HP 9821 - display and tape transport issues #VintageHPComputers

 

Hi Marius,

 

It’s some time ago and I don’t remember which LDR I ordered.

I looked at epay and found several sellers who sell 5mm LDR’s. So the best thing to do, is looking at the datasheet which one fits the best.

Important is R-light < 2k and R-dark is high as possible, the comparator switches at ~2.5V to get a good switching characteristic it’s important to buy a LDR with a wide Resistance range.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens mariuszmleczko@...
Verzonden: dinsdag 18 februari 2020 22:23
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9821 - display and tape transport issues #VintageHPComputers

 

Hmm...so it seems to be defective ? Rik can you propose some available on the market phototransistor for replacement ?
The symptoms described below are also same as mine (especially rewinding case).

A good LDR will display a resistance of several mega-ohms when fully dark and less than 200 ohms under strong direct light. The LDR feeds into a 741 op-amp running open-loop, thus functioning as a comparator. The comparator output will trip when the LDR resistance is around 18K.
http://madrona.ca/e/HP9830/hardware.html


Re: HP 9000 Series 300 BASIC/UX 6.3 or 6.4 wanted

Mark Bielman
 

Plan on installing this weekend on my 9000/380 with 9.10 (best I recall)
Have not fired this up in over a year! Hope I'm successful.

Plan on using this to control my (somewhat new) vast amount of test equipment.
What fun!

Too bad no free HP-UX RMB for my 720.

Mark


Re: HP 9821 - display and tape transport issues #VintageHPComputers

mariuszmleczko@...
 

Hmm...so it seems to be defective ? Rik can you propose some available on the market phototransistor for replacement ?
The symptoms described below are also same as mine (especially rewinding case).

A good LDR will display a resistance of several mega-ohms when fully dark and less than 200 ohms under strong direct light. The LDR feeds into a 741 op-amp running open-loop, thus functioning as a comparator. The comparator output will trip when the LDR resistance is around 18K.
http://madrona.ca/e/HP9830/hardware.html


HP 12016A SCSI card

Jesse Dougherty
 

would anyone happen to have a 12016A SCSI card? If so and you want to
sell or trade for some other HP hardware, let me know.

Thanks

Jesse@cypress-tech.com


Re: HP 9821 - display and tape transport issues #VintageHPComputers

mariuszmleczko@...
 

When small square "PHOTO" pcb is disconnected from "09830-66565" (main board), values are:
- 8.9K (completely dark - entire transport covered)
- 0.29K (straight and intense light beam from phone LED)

Same values in the soldering place (shown on before photo), and between 3 and 9 pins of the "PHOTO" pcb


Re: HP 9821 - display and tape transport issues #VintageHPComputers

 

Did you disconnect the sensor from the PCB.
The small pcb's are connected to the big one with pin which is detachable. The only way to get good readings is with the ldr disconnected.
R-dark should be more than 200k R-light should be below 1.5k roughly.

-Rik




On Mon, Feb 17, 2020 at 8:37 PM +0100, <mariuszmleczko@...> wrote:

Display board is fixed (thanks to Mr Matthieu Benoit)

Regard the tape LDR sensor.....

I was able to get into sensor board from behind:
https://groups.io/g/VintHPcom/photo/240360/0?p=Created,,,20,2,0,0

And here I got a question.
LDR resistance when measured in the place of soldering (marked on the photo above) is reacting to light without any doubt.

Measured values are:
- 5.5K in no light condition (totally covered sensor)
- 0.5K in bright light condition (direct and intense light beam from phone LED lighter)

But....I've measured it only soldered - like on the photo - and not sure how to interpret those results.
Shall I desolder it and measure out of the board....or is it already possible to give a verdict that it is OK or not ?

Will be thankful for help.


Re: HP 9821 - display and tape transport issues #VintageHPComputers

mariuszmleczko@...
 

Display board is fixed (thanks to Mr Matthieu Benoit)

Regard the tape LDR sensor.....

I was able to get into sensor board from behind:
https://groups.io/g/VintHPcom/photo/240360/0?p=Created,,,20,2,0,0

And here I got a question.
LDR resistance when measured in the place of soldering (marked on the photo above) is reacting to light without any doubt.

Measured values are:
- 5.5K in no light condition (totally covered sensor)
- 0.5K in bright light condition (direct and intense light beam from phone LED lighter)

But....I've measured it only soldered - like on the photo - and not sure how to interpret those results.
Shall I desolder it and measure out of the board....or is it already possible to give a verdict that it is OK or not ?

Will be thankful for help.


Re: That 9816 keyboard...

Piero Andreini <pieroandreini@...>
 

Hello Andres,

you are doing absolutely fantastic job, like always!

Piero

Il giorno 15 feb 2020, alle ore 10:28, Anders <anders.gustafsson@...> ha scritto:

Put together a project page. The 100-series uses a similar interface, albeit with different pinout. Will look into that as well. It should be possible to create a design that accomodates both. http://www.dalton.ax/HPkbd/


Re: That 9816 keyboard...

Anders
 

Put together a project page. The 100-series uses a similar interface, albeit with different pinout. Will look into that as well. It should be possible to create a design that accomodates both. http://www.dalton.ax/HPkbd/


Re: Solving HP 9825 despooling problem QIC40/80 tapes

 

On Feb 12, 2020, at 9:15 AM, CuriousMarc <marc.verdiell@gmail.com> wrote:

Well done Sherlock! Waddaya know. I always assumed the LS had the same functionality as the straight 74xx.
Also for info the distance between holes is widely different between DC100 and DC2000, although it does not matter here.
The 9825 source code looks for explicit distances between holes to make decisions about how to handle the tape. You can see this if you look at the FDVRT.BPC file's comments. I have not figured out how much tolerance there is in the distance measurement code.


Re: That 9816 keyboard...

 

Nice work Anders, looks good.

-Rik




On Wed, Feb 12, 2020 at 7:10 PM +0100, "Anders" <anders.gustafsson@...> wrote:

Anyway. The adapter is now ready and also supports the national layouts supported by the 98x6.


Re: That 9816 keyboard...

Anders
 

Anyway. The adapter is now ready and also supports the national layouts supported by the 98x6.


Re: 150 series 45611B with no display

Piero Andreini <pieroandreini@...>
 

Hello Adrian, I need bus extender, may you want to sale one to me?

1901 - 1920 of 4827