Texas Instruments TI Programmer Calculator (1979)

An interesting one-chip offering from TI: not such much a 4 banger, but more of a 9 banger, which is to say, logical and arithmetic functions, and a memory, and operation in decimal, octal or hex modes. From Brent Hilpert’s website, via the oldcalculatorforum mailgroup.

Texas Instruments TI Programmer Calculator (1979)

via Early Electronic Calculator Technology Reference


Interesting, I had never heard of this one. The HP-16C got all the thunder.

Maybe it was because it was not programmable that it never hit my radar, and the fact that Radio Shack never sold it.

It definitely was my most useless and unused calculator. While coding or building digital stuff you’ll grok octal and hexadecimal so quickly, that such a toy just will end in some drawer and/or collect dust.

I dunno; I found it fairly useful for calculating branch offsets when hand-assembling code.

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My singular issue with branch calculations is whether or not to add/subtract 1 or 2 from the values. Always mess that up, but then I never did enough assembly for it to become ingrained.

There’s a story…
Woz and the forward reference

Yea, he’s going deeper than I ever would. He’s computing not simply the correct offset, but the instructions that he’s planning on skipping over.

I struggle with just the offset when I already know the destinations! :slight_smile:

The way I do it, there’s no special casing (this is on 6502): an offset of 0 is do nothing, it’s a branch to the very next instruction. So either I count forwards, from 0, which is easy, or count backwards: ff, fe, fd, fc, … which I don’t find too difficult, now I’ve done it a few times. It’s the same for emulators: they don’t need to special case forward or backward, they only have to treat the offset as signed.

Yeah, counting backwards is the trick I use when hand-assembling code, but it’s a bit slow when you need to branch back a hundred bytes. :-)