Value of the HP-21S

[Joerg Woerner]

Hi There,

Recently I received a HP-21S and tried to find out its value. Here in the Museum I found the entry "Easy to get" but the price tag is missing. Searching two weeks the huge eBay auctions I found not even one of the HP-21S.
What's on with the HP-21S? Is it very common or just unpopular due to the missing ENTER key ?

HAPPY NEW YEAR !

Greetings from Germany, Joerg

[Mike (Stgt)]

Seems you like to sell it. If you know it's value just tell me pls off-list: hp41cx@web.de

"Monte Carlo" fehlt noch in meiner Sammlung. Grüße aus Stuttgart

Ciao.....Mike

[Holger Weihe]

Hi,

according to my ebay-price-history at http://www.hweihe.de/hp/preistabelle.htm
only one 21S was sold in the last time. It went for 87 Euro.

I am also interested. So if you want to sell it, please send me a mail...:-)

Holger

[Frank B. (Germany)]

I got a HP-21S for Euro 21.10 in July 2002 (Ebay Germany). Kind of bargain, I think. There were only 3 bids, although it was described as "Hewlett-Packard Taschenrechner 21 S".

No, I don't want to sell it.

Regards, Frank.

[Jan (CH)]

What is 21S? Mine is 21 without "S"
Thanks

Jan

[Raymond Del Tondo]

The 21S is a member of the pioneer series.
It looks somewhat similar to the 20S,
but with more statistical features.

Raymond

[Paul Brogger]

The HP-21S is a low-end Pioneer, a precursor to the HP-20S.

I don't think they're talking about the (Woodstock) HP-21 at those prices . . .

[Joerg Woerner]

That's correct - the HP-21S is sandwiched between the HP-20S and HP-32S.
From the HP Database I learned that they all use similar architecture with different RAM / ROM size.
Is there a special meaning of the "S" ? I noticed (I'm not a HP expert like you) that some modern calculators carry this designation - e.g. HP-42S, 6S, 30S...). What is your explanation ?

Greetings from Germany, Joerg

[R Lion (Spain)]

You can see it here: http://www.fbalzer.de/tr/hp21s.jpg

[Frank B. (Germany)]

Right, that's the one I got for Euro 21.10! Except the small scratch on the faceplate it's in pretty good condition.

Frank.

[Vieira, Luiz C. (Brazil)]

Hi, Joerg;

as always, it's good reading from you in here.

Primarily, the "S" should mean "Scientific", as all of the new-architectured calculators are "continuous-memory" based (TI uses the term "constant-memory", right?), so there is no "need" for a "C" sufix. Some earlier models had a "C" instead of an "S" to identify the constant-memory feature: HP41 series, all voyagers, HP28C (later an HP28S). Even the first 48 series was designated as Scientific, at the same time the HP42S and many scientific calcs (Pioneers), as you mentioned in your post.

The same applies to the Business: 10B, 14B, 17BII, 19BII...

There are exceptions, of course: HP12C, being the "C" a remaining constant-memory reference, and the HP27S, a do-everything model, with scientific and financial (business) resources.

Best regards.

[David Smith]

I have bought several HP21 woodstock machines on Ebay in the $20-$25 range... secretly hoping that they had some defect which would justify me scrapping them out for the ACT chip. Guess what, all but one were pefectly good and worked fine after a little cleaning. One had a corroded keyboard. Its ACT chip and case back restored two HP25 units to their former glory.