Texas Instruments TI Programmable 59

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Texas Instruments TI Programmable 59

TI Programmable 59

Type: Programmable Semi-Algebraic Electronic Calculator
Size: 6.5 x 3 inches / 16 x 8 cm
Serial/Lot number: 0983885/ATA0182
Date of Manufacture: January 1982

Digging this out of the basement after many years of neglect. The manuals aren't too mildewy. Found the power supply down there, too, and found a guy who sells rebuilt batteries on the net. All working pretty good, even the card reader. No box, though. Got rid of that years ago. That's the difference between units I buy as collector's items and units I buy for actual use. The latter get used up. Ah, well. Every time I buy something, I think they'll make it forever. Old age, I guess...

The TI Programmable 59 was the Serious calculator of its generation. Partitionable memory, internal magnetic card reader, and a ROM program module slot (With a general purpose ROM included). When I had decided to graduate from the TI-57, I was faced with the decision of this unit, or the contemporary HP-41C. I actually did a cost/benefit/functional analysis, and chose the 59, for $180 (A friend got it for me wholesale). I was never under the impression that it was better than the HP-41C, but a) I knew TI calculator programming and b) it was more bang for the buck. Got plenty of good use out of it, too, before the battery pack croaked in the middle of an important physics course. (I finished the course on the trusty Pickett 1010.)

I have several ROM modules for this unit, not all of which I ever used for anything. I have the Master Library (included with the calculator), Math/Utilities, Electrical Engineering and Navigation modules. Each module had a score or so prepackaged routines. Visible in the picture of the unit is the cheater card for program 2 in the Master Library module. A quick couple of keystrokes and the top row of keys were defined to match the labels provided.

The ROM modules were actually open source. You could copy any ROM program into RAM to examine or modify it. You could then save your modified copy to magnetic card. Pretty advanced thinking for 1982, really.

Calculator function was actually pretty basic; not much beyond trig functions and logarithms. No factorial function, even. The calculator focused on programmability and memory management, with the mathematical functionality relegated to the ROM modules. That wasn't annoying very often...