HP Forums

Hello all,

I just got a HP97s with good shape both calculator & BCD interface.
the calculator seems work well. but for the BCD interface. Does anyone know how to test it?

I just tested it with multi-meter to measure the voltage between:
---- pin1(GND) and pin26 DC 0V
---- pin1(GND) and pin27 DV 0.3mv
---- pin1(GND) and pin28,29,30/ it is DC4.5V
---- pin1(GND) and pin6~25 & P31~50/ it is DC5.3V

please give me some advice, thanks!

BR,
bai

Do know this article?
https://www.hpmuseum.org/cgi-sys/cgiwrap...i?read=380
You can build your own test connector using the MM80C98 chip. The plug is a Centronics 50 pin.
I think the original test connector is a double layer PCB. So not easy to change a faulty chip.

The test program is inside the installation and operating guide found at
https://literature.hpcalc.org/community/...iog-en.pdf

Good luck
Andi

Hello Andi,

Thank you for your reply.
Yes I checked the article and go through the manuals.
It is hard for me to make a test connector.

I would like to think it works.. haha

BR,
Bai

Mouser Electronics lists the Amphenol 57-30500 connector. Not sure if it is the same as the 97S module or the mating connector.

cheers

Tony

Thank you Tony!
Maybe need your replacement CPU board finally.

(07-15-2023 09:38 AM)teenix Wrote: [ -> ]Mouser Electronics lists the Amphenol 57-30500 connector. Not sure if it is the same as the 97S module or the mating connector.

cheers

Tony

it lists it as obsolete, with 0 in stock, as does DigiKey. There are other connectors with a variety of attachment options; they cost under USD 10. Your best bet is finding a friend above a certain age who may still have a SCSI Centronics cable (50-pin; the printer cables had 37 positions, not 50) that you can cannibalize.

The MM80C98 is also long since obsolete; the 74LS368 looks like it has the same functionality, but double-check with the data sheets.

(07-18-2023 01:33 AM)John Ioannidis Wrote: [ -> ]it lists it as obsolete, with 0 in stock, as does DigiKey. There are other connectors with a variety of attachment options; they cost under USD 10. Your best bet is finding a friend above a certain age who may still have a SCSI Centronics cable (50-pin; the printer cables had 37 positions, not 50) that you can cannibalize.

The MM80C98 is also long since obsolete; the 74LS368 looks like it has the same functionality, but double-check with the data sheets.

Ahh ok :-)

tedds.com $10

TheBay has some second hand.

Curious what the hex inverter is used for.

cheers

Tony

(07-18-2023 01:33 AM)John Ioannidis Wrote: [ -> ]The MM80C98 is also long since obsolete; the 74LS368 looks like it has the same functionality, but double-check with the data sheets.

Current ebay listing here in Germany (59 sold, more than 10 available) for the MM80C98

https://www.ebay.com/itm/381669844310
Ships worldwide with a LONG list of exclusions. So less than 10 countries left.

Another one https://www.ebay.com/itm/222440092258 - pack of 5 that ships nearly worldwide.

Or from China: https://www.ebay.com/itm/323482296882

Andi