Carey S. writes: > If it only manipulates numeric data, it is a calculator. It must be able to > search, > rearrange look up, compare, and display characters. I would have thought > that to be > obvious. <snip> ...if it cannot give a text description of the answer, it is > a > calculator.
> Also something about arbitrary branches to any location (ok, any executable > location if > something has separate code and data memory). So, are the HP 9820, HP 9830, Tektronix 31, Tektronix 4051, and the Texas Instruments SR-60 calculators or computers? All of them were at least initially marketed as calculators(except perhaps the 4051, but it could definitely serve as a calculator, though massive overkill). This was because if someone submitted a capital equipment request for a "computer", bean counters would immediately reject it, while calculators would sail right through. Why? Because computers were big complicated machines that required expensive, brainy people to support, and they needed all kinds of "extras" like special power, air conditioning, storage systems, printers, terminals, maintenance contracts, installation fees, and other stuff that cost even more money. At least, that was the mentality, be it right or wrong. It has been historically documented as such in numerous books written about that period in time. Calculators... well, you just took 'em out of the box, set them on the desk, plugged them in and off you go. Didn’t really matter if it was a four-banger, or something like an HP 9830(if all you wanted to do was calculate with it). With machines like this, engineers and scientists could get themselves a "computer" without the fuss of having to say it was a computer on their equipment request. All of the above devices could be programmed to manipulate and display and/or print alpha-numeric and special characters, They could be programmed to search, compare, find, re-arrange, sort, combine, and manipulate numerical and non-numerical data. They all also had the ability to branch to an arbitrary location within a program, though off the top of my head, I think that all of the machines except the 4051(EXEC) (and maybe the HP 9830, I can't remember off the top of my head - it may have required a special ROM module to be added in order to do that) didn't have the ability to branch to arbitrary data in memory and execute it. All of the named machines certainly could qualify as a computer, right? At the same time, each of them could have a mathematical expression (some even with variables) entered as it would be written on paper, without any programming, and they would display/print the numeric result after pressing a single key to terminate the entry. These expressions could include functions such as logarithms, trig, roots, exponentials, etc., just like a calculator. Perhaps that really does make them calculators? Why did Digital Equipment Corporation brand their computers as "PDP"? It was an acronym for "Programmed Data Processor". A "PDP" isn't a computer for all bean counters might know. The point of this designation (which was only the PDP part, not its expansion) was to allow capital requests to get through the approval process without the fussy "computer" word in the request. You'd just write down "PDP 11/70" on the request. As long as the money was in your budget, the worst that might happen is someone from finance may ring you up and ask you "What's a PDP 11/70?", and you could say, "Oh, it's a really fancy calculator" (not a lie), and they'd go away happy, and your request would be granted, even if it amounted to tens of thousands (or more) dollars. Weeks later, you'd have an really powerful Programmed Data Processor show up at the loading dock, no one really the wiser. This is probably exaggerating the reality a bit, but the true point of the PDP designation was to make it easier for engineers, scientists, and anyone else that needed a real computer but had a bureaucracy to go through before they could get one. Perhaps the distinction noted isn't quite as clear cut as indicated. -Rick PS: Carey, I am working on a response to your message from yesterday, it's just taking a while, hopefully it'll arrive to you later today or tomorrow sometime. -- Rick Bensene The Old Calculator Museum https://oldcalculatormuseum.com
