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Craig Sawyers 31st Jul 2021 11:28 pm

Old calculators.
Split from this thread:-

I have (among too many other HP calculators) an HP15C, and an HP15C special edition, which has an ARM processor and goes like a rocket as compared with the original. Otherwise identical functionality.


TonyDuell 1st Aug 2021 10:49 am

Re: RS 8 page catalogue.

Originally Posted by Radio Wrangler (Post 1394448)
HP11C.... "Woodstock" family of calculators, early 1980s

I'll agree with the date, but the HP11C is a 'Voyager'. The 'Woodstock' family is the HP21, HP22, HP25, HP25C, HP27, HP29C family from the mid-1970s.

The HP11C (scientific) and HP12C (financial) were the first 2 members of the Voyager family to be released, They were later joined by the HP15C (advanced scientific with solve, integrate, etc), the HP10C (cut down scientific, which did not sell well) and HP16C (computer programmer's machine with bit operatons, binary/octal/hex modes, etc).

The Voyagers used the NUT processor, similar to the one in the HP41C series. Alongside it was another chip that contained the ROM, RAM and Display Driver. This was (officially) called R2D2.

The Woodstocks used the ACT processor (Arthmetic, Control and Timing). Most were PMOS. But to make life interesting the HP27 (only) is NMOS, the power rails inside are totally different.

Radio Wrangler 1st Aug 2021 1:01 pm

Re: RS 8 page catalogue.
You're right, and I have two of the things! (11Cs) Voyager they are

CMOS and batteries last for years.

Still have my original HP45.


TonyDuell 1st Aug 2021 1:37 pm

Re: RS 8 page catalogue.
Never had an 11C (not much point when I have a rather large HP41 system) but I still use my 16C _a lot_. You're right, the batteries last for years.

I assume you know about the stopwatch in the HP45.

Craig Sawyers 1st Aug 2021 2:44 pm

Re: RS 8 page catalogue.
HP34C, HP15C, HP15C special edition (ARM processor), HP12C, HP12C Platinum, HP28S, HP50g, HP35S and HP Prime. And two HP82240B IR printers.

Yeah, I know. Just don't get me going on the Tektronix, HP and General Radio test gear, the slide rules or the fountain pens.


TonyDuell 1st Aug 2021 3:04 pm

Re: RS 8 page catalogue.
I guess I can post my little collection (just the calculators...):

Desktop calculators : HP9100B, HP9810, HP9820, HP9830, HP9815, HP9825, HP9831

Handhelds : HP35, HP45, HP55, HP65, HP80




HP31E, HP32E, HP33C, HP34C, HP38C


HP41C, CV, CX, card readers, thermal printers, barcode wands, ROM modules, HPIL, MLDL

HP71B, HPIL, card reader, modules

HP75C, modules

HPIL tape drives, disk drives, thermal printers, thinkjet printers, impact dot matrix printer, HPIB, RS232, parallel, video interfaces



And probably some that I've missed. I think I've been inside just about every HP handheld, including the 95C...

Craig Sawyers 1st Aug 2021 3:25 pm

Re: RS 8 page catalogue.
There is clearly hope for me yet!

Radio Wrangler 1st Aug 2021 4:00 pm

Re: RS 8 page catalogue.

Originally Posted by TonyDuell (Post 1394643)
I assume you know about the stopwatch in the HP45.

Mine has the crystal fitted :-)

Jon_G4MDC 1st Aug 2021 5:48 pm

Re: RS 8 page catalogue.
Is this becoming a thread of it's own?
Actually, surely, there must be one very much like it already in existence?

Jon_G4MDC 2nd Aug 2021 1:07 pm

Re: Old calculators.
Thanks Mods for splitting the thread.
As HP was being discussed it has reminded me of an HP67 I have had in the shed for a long time.

It's original battery pack went defunct and is now lost. I don't suppose there is any chance of obtaining a replacement apart from making something from scratch.

The 3 way connector for the DC supply is also gone - would that be the same story would anyone happen to know please?

TonyDuell 2nd Aug 2021 2:22 pm

Re: Old calculators.
There was a chap in the States who made replacement battery packs for these calculators. I have no idea if he still does, but looking on E-bay may be worthwhile.

Alternatively you can put new cells into an old pack. It's just 3 NiCd cells in series. I probably have a spare housing and contact strips somewhere, the problem would be finding them.

Originally (HP35) the 3 pin power connector was wired so that the middle pin was logic ground, one outside pin was +4V or so to the logic, the other went to the +ve side of the battery. A spring contact connected the outside 2 pins when the charger wasn't plugged in so that the battery powered the calculator. The charger contained a voltage regulator to run the logic and a constant current supply to charge the battery.

In the models with card readers -- HP65 and HP67, it's much the same but the card reader IC runs directly off the battery. As a result these machines will not handle cards if there isn't a good battery fitted. In fact, in the case of the HP65 the card reader chip can be damaged if you plug the charger in without a battery (or with an open-circuit battery) in the calculator, it can't stand the 15V or so open-circuit voltage of the constant current side of the charger. Note that this applies even if the calculator is switched off! The card reader chip was modified to withstand this voltage, and HP67 machines should be safe, but it's not a good idea to risk it. Some people like to charge the battery outside the calculator as a result, there was even a little HP battery holder unit ('Reserve Power Pack') that connected to the normal charger and took a battery pack.

It is not clear what you are missing. The 3 pins on the calculator? The socket on the end of the charger lead? Or the complete charger unit?

Mains chargers do turn up from time to time, they are not that rare. The 12V charger to power the machine in a car is a lot rarer. So is that battery holder thing I mentioned.

G6Tanuki 2nd Aug 2021 3:36 pm

Re: Old calculators.
HP33C here - bought for me by my father from a company called "Sumlock Bondain" in Birmingham for me to take with me when I went to Uni.

[I believe Sumlock Bondain were associated with the 1960s ANITA calculators]

The HP33C still works - sort-of. It's got the dreaded poor-contact-between-the-chips-and-the-PCB issue so you sometimes have to squeeze it a bit to get all the digits to light. Also the little angled PCB-with-springy-contacts-riveted-on-it that serves as one wnd of the battery-compartment has suffered from battery-corrosion, one of the springy contacts became brittle and snapped off during a battery-change. It's botched with a soldered-on bit of the phosphor-bronze=wool stuff used as a RFI-proofing gasket.

Paul_RK 2nd Aug 2021 3:52 pm

Re: Old calculators.

Originally Posted by G6Tanuki (Post 1394921)
[I believe Sumlock Bondain were associated with the 1960s ANITA calculators]

Yes, and they're still going, based now in Norwich.

"...Sumlock-Bondain, a company with its roots in the Sumlock-Anita calculator business. It was formed by people made redundant by the takeover of Sumlock-Anita by the U.S. giant Rockwell, who did not want to see their talents go to waste and decided to continue in that same business.
Originally they sold the Sumlock calculator range but when that was wound up by Rockwell, they found favour with Texas Instruments, for whom they are wholesalers, and with Hewlett-Packard, for whom they act as a main agent."


Jon_G4MDC 2nd Aug 2021 3:55 pm

Re: Old calculators.
Thanks for the info. The whole battery assembly is gone. I was going to restuff it with NiCads but it never happened. I might come across it one day.

The tip about no battery and the card reader is good info. I won't risk it!

I have no charger / AC adaptor at all. I think the cable parted inside the housing and again it is long lost anyway. Might look out for a replacement if they do turn up from time to time.

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