TI-57 online in-browser (with a personal connection!)

Here’s Jeff Parsons’ very nice microcode-level emulator of TI’s affordable programmable calculator, the TI-57:
TI-57 with Original ROM and Diagnostics

There’s also a version with a revised ROM and the backstory for that…

And here’s his blog about his own TI-57 and what he did next:

It may be the first open-source bit-identical emulation of this calculator - there’s a nearby page about the ROM and about a previous closed-source
Texas Instruments TI-57 ROMs

One possible source of ROM data is from TI’s patents, but they seem to differ in small ways from the ROM embedded in the closed-source emulator. Another source is from photographs of the chip used in the calculator - and Sean Riddle decoded the ROM from photos taken by John McMaster

… and that’s the personal connection - John’s photos are of the chip I took out of my own TI-57!

My first programmable calculator

See also Ten thousand primes on a programmable calculator

(via Claus Buchholz’ TI-57 Memory Map as linked in the RCL-57 thread on HPMuseum forums which lays out how to make good use of 160 bytes of RAM.)

A calculator one can trust.