HP-35 for sale - but which version do I have?

[chancewest]

I have a very old HP-35 that used to belong to my Grandfather for sale. How do I go about working out which version of the HP-35 I have?

Clues, based on some random scanning of webpages:
* Small square keys with text printed above.
* No "red dot" on power slider.
* Power supply plug is circular and has two pins - that's why I haven't been able to turn it on and test yet.
* Serial number begins "1302S", followed by five digits.
* No dot on five key.
* Comes in a large grey plastic carry case.

If you have any questions ask away!

[Sylvain Cote]

From the picture you probably have a version 3.
You can look here and here
Sylvain

[chancewest]

It looks like the third or fourth (but could be fifth) on that row of six. Is it worth anything?

[Sylvain Cote]

(04-23-2014 06:31 PM)chancewest Wrote:  It looks like the third or fourth (but could be fifth) on that row of six. Is it worth anything?

On the picture you have from left to right
- proto-1 : beige casing, yellow keys
- proto-2 : black casing, yellow keys
- v1 : "HEWLETT-PACKARD" front, RED DOT, functions name above keys
- v2 : "HEWLETT-PACKARD" front, functions name above keys
- v3 : "HEWLETT-PACKARD 35" front, functions name above keys
- v4 : "HEWLETT-PACKARD 35" front, functions name on keys

Look at the front label, it's either a v2 or a v3 calculator.
Search on TAS and you will have your answer on the value.

Best regards,

Sylvain

[Visu]

It's a v3 !

[chancewest]

Is a version 3 good?

[chancewest]

Quote:Search on TAS and you will have your answer on the value.

Best regards,

Sylvain

What is TAS?

[rprosperi]

(04-24-2014 08:55 PM)chancewest Wrote:  

Quote:Search on TAS and you will have your answer on the value.

Best regards,

Sylvain

What is TAS?

The Auction Site - A well known auction website that is rarely uttered here by name. Long story...

[Sylvain Cote]

(04-24-2014 08:55 PM)chancewest Wrote:  

Quote:Search on TAS and you will have your answer on the value.

Best regards,

Sylvain

What is TAS?

The Auction Site (eBay)

[Jeff O.]

(04-23-2014 06:04 PM)chancewest Wrote:  * Power supply plug is circular and has two pins - that's why I haven't been able to turn it on and test yet.

If you have a power supply with a round plug and two pins, it is not for the HP-35. The HP-35 power supply plug is rectangular, and has three pins, matching the recess on the back of the calculator.

If you want to test it, take the battery compartment cover off and apply 4.5 Volts DC to the two prongs in there, according to the polarity indicated below:

(04-24-2014 08:53 PM)chancewest Wrote:  Is a version 3 good?

It looks to be in good cosmetic condition, and if it works it is definitely "good". As far as value, version 1 (red-dot) units command the highest value, probably five to ten times the value of other versions. Version 2 units with the bugs may be next highest in value, I guess kind of like the desire for misprinted stamps or coins that got into circulation. Version 2 without bugs might also be valued, since they were obviously returned to HP and "repaired" to eliminate the bugs, demonstrating HP's commitment to quality above all else. Version 4 may be next, since they have the redesigned keyboard and represent the last of the line. So maybe version 3 is least collectible, but certainly desirable as either a single example of such a fine machine, or to fill out a collection.

The above are solely my impressions, nothing more. If you want maximum value, find a way to test to see if it works, then put on eBay. Or watch a few ebay auctions, decide on what you feel is a fair price, and sell to a collector here. Note that many sellers at ebay put them up with ridiculously high buy-it-now prices, hoping to hook a neophyte collector who does not know real value. So only count completed auctions in your assessment of value.

[chancewest]

Jeff,

That's fantastically useful re: the power supply - I'll give it a try.

Unfortunately I'm moving house so the HP-35 has been all packed up, but I'll be back, MoHPC!

[chancewest]

(04-25-2014 12:47 PM)Jeff O. Wrote:  As far as value, version 1 (red-dot) units command the highest value,

Dumb question, but where is this red dot found? I haven't seen a red dot on any of the HP-35 photographs I've seen!

[Jeff O.]

(04-25-2014 04:07 PM)chancewest Wrote:  Dumb question, but where is this red dot found? I haven't seen a red dot on any of the HP-35 photographs I've seen!

See the (somewhat hard to see) red dot to the right of the "ON" label next to the on-off switch in the picture below. It is a hole through which a red color appears when the switch is slid to the ON position. When in the OFF position, black (or dark gray) shows through the hole.

[Massimo Gnerucci]

(04-25-2014 04:07 PM)chancewest Wrote:  

(04-25-2014 12:47 PM)Jeff O. Wrote:  As far as value, version 1 (red-dot) units command the highest value,

Dumb question, but where is this red dot found? I haven't seen a red dot on any of the HP-35 photographs I've seen!

[Jeff O.]

(04-25-2014 04:06 PM)chancewest Wrote:  That's fantastically useful re: the power supply - I'll give it a try.

If you do try it, it would probably be best if you can clip your power supply leads to the prongs. The on/off switch often gets a little "fiddly", such that you have to slide it back and forth or jiggle it around in the ON position to get it to come on. Might be hard to hold power supply leads onto prongs with two hands whilst doing the required jiggling with your third hand.

Also note the metal strap in the charger plug well, shown in the battery polarity picture provided previously. If the calculator has ever been opened, this piece might have gone missing. In that case the battery prongs can no longer be used to power the calculator as that strap connects the outer two pins and is part of the circuit from the battery prongs to the calculator internals. You can power the calculator by applying the correct voltage to the correct two pins in the connector well. I believe it is positive to the left pin in the picture and negative to the middle pin, but am not 100% sure.

(04-25-2014 04:06 PM)chancewest Wrote:  Unfortunately I'm moving house so the HP-35 has been all packed up, but I'll be back, MoHPC!

Take your time, we'll probably still be here when you get back.