On 18 Apr 2004 00:46:03 -0400, the renowned (DoN.
Nichols) wrote:

In article ,
Spehro Pefhany wrote:
On Sat, 17 Apr 2004 08:42:19 -0700, the renowned "Robert Swinney"
wrote:

[ ... ]

It takes a
helluva lot more processing power to enter equations "the natural way".

Nah, the stack on early HP calculators was 4 levels.

It depends on what you mean by "early". The 9200 and 9200B
desktop machines (which is where I got my start programming HP
calculators) were three levels of stack -- with real *core* memory, and a
mag card reader/writer. All three levels of stack were visible at once
on the tiny crt display. Since it had core memory, you could turn it
off, and when you turned it back on, your program was still there, ready
to run.

Handheld, of course. I picked up one of those (the 9200B) at a
stationery shop in Downey CA back in the early eighties for song
($40), with JPL stickers all over it. CRT display. Gold-plated PCBs.
VERY nice, and it still worked. Unfortunately it disappeared last time
we moved to a new house. Very sad, it was a beautiful example of
American engineering. It cost about $4000.00 in '68 according to an
old (hardcover) HP catalog I had. Back when HP was a real instrument
company.

It also had a clamshell printer which fit on top of the case
like a toupee, and it printed on an electro-sensitive paper (conductive
aluminum foil, and it wrote by blasting through with electrostatic
discharges that to the black background on the paper. As your printout
extended, you were unfurling an antenna to broadcast your calculations
to the world. :-)

I never saw that.

So -- when I got my HP-45, I was already comfortable with RPN,
and also with a slipstick.

Enjoy,
DoN.

The HP-35 and 45 were just a bit before my time- I knew of them, but
couldn't afford (or justify) them.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
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