41 Turns 25
Jul. 20th, 2004 08:18 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
major_clangerHappy 25th Birthday (give or take a week or so) to the Hewlett-Packard HP-41C, Giant amongst Calculators.
Why am I celebrating the quarter-centenary of a calculator? Those who know me may be aware that I'm fond of antique electronics in general, old calculators in particular, and the products of Bill (Hewlett) and Dave (Packard) especially so. But even in the (surprisingly large) world of HP calculator collectors, the '41 is held in especially high regard.
These days, HP is known mainly as a manufacturer of printers; for much of its history, it was famous mostly for electronic test equipment or mainframe computers. From the early 1970s until the mid-1990s though, HP was most widely known for making calculators. Widely known, that is, in the same way that Norton were widely known for building motorbikes, Mag-Lite for making torches, and Aga for making oven ranges. When you bought HP, you didn’t just buy a calculator, you bought a Calculator. In fact, the comparison with Agas is a good one; like Agas, HP calculators were seen as expensive, superbly crafted and - thanks to their used of the ‘Reverse Polish Notation’ method of number entry - rather odd and even awkward to use. And, like Agas, they attracted a devoted following that wouldn’t even dream of using any alternative. From the mid-70s to the mid-80s, literally millions of scientists, engineers and business people world-wide owned HP calculators, and many of them became so enamoured of them that they formed owners’ clubs, published journals of programs and applications, and spent hours of their time to exploring the capabilities of their machines.
These days, we tend to think of calculators as being cheap to the point of disposability, and almost all are built to a suitably low-cost standard. Back in 1972 though, the pocket calculator was an expensive gimmick, powered by chunky rechargeable batteries to power an LED display for a few hours at a time. Early models were limited to simple arithmetic, but that year HP introduced the HP-35, the world's first 'scientific' calculator (i.e. capable of handling logarithms and trig functions) and overnight rendered the centuries-old technology of the slide-rule obsolete.
The HP-35 was expensive to produce, and HP (which was used to producing high-end test equipment anyway) built it to an appropriate standard. Over the following years, owners of HP calculators became accustomed to solid, well-engineered products, comprehensive and well-written manuals, and (and this seems to be the feature that HP fans remember most fondly) nice big keys that operated with a firm but not at all plasticky click.
In 1974, HP brought out the HP-65, the first programmable calculator. This meant that it could remember a series of keystrokes - say those to carry out a complex calculation - and repeat them with fresh inputs as often as required. The HP-65 included instructions to allow looping and program flow control, and had a built in reader/writer for small magnetic cards to allow programs to be stored. It was in other words a simple, but small and (by the standards of the time) cheap computer, and it was a computer that was 100% the owners to do with as they wished. In the days when those lucky enough to have access to a computer usually had to make do with remote time-share on a mainframe, the prospect of having even a relatively basic one of one's own was little short of miraculous. The HP-65, and its more powerful replacement, the HP-67, sold like hot cakes, and led to the establishment of a thriving community of user groups dedicated to swapping programs and programming hints.
It was in July 1979 though that HP brought out what would later be seen as their masterpiece: the HP-41C. A radical development of the HP-65/67 line, it made use of the latest technology such as alphanumeric LCD displays, non-volatile memory and plug-in ROM modules. Even more so than its predecessors, the '41 could serve as a small but, for its size and price, relatively sophisticated computer, especially for tasks involving mathematical computation. (It's worth remembering that at the time, many personal computers either didn't handle floating point maths at all, or did so with dismally poor precision.) At a time when even home computers were still expensive and cumbersome, programmable calculators were an attractive and popular alternative, and the '41 was the most popular of the lot. HP ended up keeping it in production for eleven years, and although it was updated somewhat along the way (mine was an HP-41CX, with extra memory and functionality) that's still a staggering lifespan in an industry where Moore's Law rules.
I first got my hands on one in 1982 or so, when a friend of my Dad's very kindly loaned his to me at weekends. A couple of years later I scraped together enough money to get my own, which saw me happily through A-level science and maths, as well as being used for more interesting stuff like calculating planetary orbits. Much to my regret I ended up selling it at university, replacing it with an HP-28, a machine that whilst in many ways much more powerful (it could do algebra!) was actually not nearly so much fun to use. Perversely, the more powerful calculators became, the less scope there was to do more than just use them. In the Good Old Days, if you wanted to invert a matrix, you sat down, wrote a program to do it, rewrote it several times to fit in the limited memory available and then wrote it up for the owners' club magazine. With the new calculators, you just pressed the 'invert matrix' button... By this time I'd also discovered sf fandom, and one obsession was replaced by another.
But old loves never quite die. When I had a PC, my default calculator was V41, a superb (and very accurate) '41 emulator, and I now have the P41CX emulator for my Palm Tungsten T3. There's nothing quite like the real thing though, and a while back I ended up buying a second-hand real, solid HP-41. In 25 more years I can dig it out and (as long as I can find some N-size batteries) scare youngsters with what we used to programme when we were young...
MC
Why am I celebrating the quarter-centenary of a calculator? Those who know me may be aware that I'm fond of antique electronics in general, old calculators in particular, and the products of Bill (Hewlett) and Dave (Packard) especially so. But even in the (surprisingly large) world of HP calculator collectors, the '41 is held in especially high regard.
These days, HP is known mainly as a manufacturer of printers; for much of its history, it was famous mostly for electronic test equipment or mainframe computers. From the early 1970s until the mid-1990s though, HP was most widely known for making calculators. Widely known, that is, in the same way that Norton were widely known for building motorbikes, Mag-Lite for making torches, and Aga for making oven ranges. When you bought HP, you didn’t just buy a calculator, you bought a Calculator. In fact, the comparison with Agas is a good one; like Agas, HP calculators were seen as expensive, superbly crafted and - thanks to their used of the ‘Reverse Polish Notation’ method of number entry - rather odd and even awkward to use. And, like Agas, they attracted a devoted following that wouldn’t even dream of using any alternative. From the mid-70s to the mid-80s, literally millions of scientists, engineers and business people world-wide owned HP calculators, and many of them became so enamoured of them that they formed owners’ clubs, published journals of programs and applications, and spent hours of their time to exploring the capabilities of their machines.
These days, we tend to think of calculators as being cheap to the point of disposability, and almost all are built to a suitably low-cost standard. Back in 1972 though, the pocket calculator was an expensive gimmick, powered by chunky rechargeable batteries to power an LED display for a few hours at a time. Early models were limited to simple arithmetic, but that year HP introduced the HP-35, the world's first 'scientific' calculator (i.e. capable of handling logarithms and trig functions) and overnight rendered the centuries-old technology of the slide-rule obsolete.
The HP-35 was expensive to produce, and HP (which was used to producing high-end test equipment anyway) built it to an appropriate standard. Over the following years, owners of HP calculators became accustomed to solid, well-engineered products, comprehensive and well-written manuals, and (and this seems to be the feature that HP fans remember most fondly) nice big keys that operated with a firm but not at all plasticky click.
In 1974, HP brought out the HP-65, the first programmable calculator. This meant that it could remember a series of keystrokes - say those to carry out a complex calculation - and repeat them with fresh inputs as often as required. The HP-65 included instructions to allow looping and program flow control, and had a built in reader/writer for small magnetic cards to allow programs to be stored. It was in other words a simple, but small and (by the standards of the time) cheap computer, and it was a computer that was 100% the owners to do with as they wished. In the days when those lucky enough to have access to a computer usually had to make do with remote time-share on a mainframe, the prospect of having even a relatively basic one of one's own was little short of miraculous. The HP-65, and its more powerful replacement, the HP-67, sold like hot cakes, and led to the establishment of a thriving community of user groups dedicated to swapping programs and programming hints.
It was in July 1979 though that HP brought out what would later be seen as their masterpiece: the HP-41C. A radical development of the HP-65/67 line, it made use of the latest technology such as alphanumeric LCD displays, non-volatile memory and plug-in ROM modules. Even more so than its predecessors, the '41 could serve as a small but, for its size and price, relatively sophisticated computer, especially for tasks involving mathematical computation. (It's worth remembering that at the time, many personal computers either didn't handle floating point maths at all, or did so with dismally poor precision.) At a time when even home computers were still expensive and cumbersome, programmable calculators were an attractive and popular alternative, and the '41 was the most popular of the lot. HP ended up keeping it in production for eleven years, and although it was updated somewhat along the way (mine was an HP-41CX, with extra memory and functionality) that's still a staggering lifespan in an industry where Moore's Law rules.
I first got my hands on one in 1982 or so, when a friend of my Dad's very kindly loaned his to me at weekends. A couple of years later I scraped together enough money to get my own, which saw me happily through A-level science and maths, as well as being used for more interesting stuff like calculating planetary orbits. Much to my regret I ended up selling it at university, replacing it with an HP-28, a machine that whilst in many ways much more powerful (it could do algebra!) was actually not nearly so much fun to use. Perversely, the more powerful calculators became, the less scope there was to do more than just use them. In the Good Old Days, if you wanted to invert a matrix, you sat down, wrote a program to do it, rewrote it several times to fit in the limited memory available and then wrote it up for the owners' club magazine. With the new calculators, you just pressed the 'invert matrix' button... By this time I'd also discovered sf fandom, and one obsession was replaced by another.
But old loves never quite die. When I had a PC, my default calculator was V41, a superb (and very accurate) '41 emulator, and I now have the P41CX emulator for my Palm Tungsten T3. There's nothing quite like the real thing though, and a while back I ended up buying a second-hand real, solid HP-41. In 25 more years I can dig it out and (as long as I can find some N-size batteries) scare youngsters with what we used to programme when we were young...
MC
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no subject
Date: 2004-07-20 01:19 pm (UTC)no subject
Date: 2004-07-20 06:21 pm (UTC)And the whole family of those devices still scares me. I am more at home with a slipstick and I barely know how to do the simplest things with one of those. I have always felt, and still do, that RPN goes against the gods and nature. If man were meant to think that way, we'd have, erm, a word for "enter" or something, in, erm, English. Or something.
Um. I'm going for a lie down now.
no subject
Date: 2004-07-21 01:09 am (UTC)I also tried it on my TRS-80 a couple of years later. The author of the program proudly claimed that it was a completely transparent compiler, you could modify anything at any level down to single bytes. Needless to say the disk was copy protected and I didn't have a backup. The first time I tried to use it I somehow modified the f****g program so that it wouldn't load any more...
no subject
Date: 2004-07-21 08:41 am (UTC)And such was the zeal of Forth converts that it blinded them to its unfriendliness.
But I bet you didn't know you run a Forth box at home. The OpenFirmware standard is Forth-based and is used in Power Macs, IBM POWER machines and in modern SPARCs as well, I believe...
If you boot your iMac to an OF prompt, you can write & run small Forth programs from the firmware command line.
no subject
Date: 2004-07-21 08:39 am (UTC)Brilliant idea, great fit for 8-bits, but I looked and I backed away slowly. Then I turned and ran.
no subject
Date: 2004-07-21 06:45 am (UTC)If Man was meant to think in infix notation, we'd have a word for "left parenthesis" and "right parenthesis"
Paging Victor Borge...
no subject
Date: 2004-07-21 08:43 am (UTC)no subject
Date: 2004-07-21 01:50 pm (UTC)Where it did score, in my view, was its use in programmable calculators. The programming model for calculators was very much akin to macro environments, i.e. recording and replaying a sequence of operations subject to limited control structures. For complex calculations this involves handling intermediate results, either by storing them in memory registers or, on an RPN machine, leaving them on the stack. Some HP calculators, including the HP-41, provided very flexible commands for stack manipulation, including the ability to do arithmetic operations between stack elements. This meant that, with a bit of thought, it was possible to write programs that minimised or avoided use of storage registers. This might not seem a major concern, but if you wanted to write a general-purpose subroutine it meant that you didn't have to worry about deconflicting access to a limited number of fixed-address memory registers.
However, old-style programmable calculators are now pretty much obsolete (if I want to repeat a calculation on my PDA, I set it up as a spreadsheet) and so this advantage has pretty much fallen by the wayside. Bit I'm still proud of the HP-41 programme I wrote that solved for the roots of a quadratic equation using only 14 program steps and no memory registers! (Several people wrote such programs: a very similar one is here, which if you ignore the first 5 steps that prompt for an input, is the same length as mine and illustrates the sort of thing that could be done with RPN).
MC
no subject
Date: 2004-07-21 05:47 pm (UTC)But what little of such things I crammed into my almost-an-arts-student undergrad Biologist's brain, I did with algebraic logic on a Sinclair Spectrum. It seemed to work about as well. I daresay my code was a lot less byte-efficient, though...
no subject
Date: 2004-07-21 12:49 am (UTC)Sadly neither was ever to be mine.