[znpy]

Quick note: if you want a full-hardware "computer" (screen, keys, cup and I/O stuff) consider buying an old Texas Instruments calculator: models up to Ti86 have a Zilog Z80-similar (ISA-compatible) inside, the TI89 and later have a Motorola 68000 cpu inside.

The Ti86/Ti89 are programmable in both Assembly and BASIC (interpreter on-rom). If you are willing to buy the data cable and fiddle with SDCC (Small-devices C compiler, a "mod" of gcc) you might program them in C as well.

Links:

* Ti86: https://en.wikipedia.org/wiki/TI-86

* Ti89: https://en.wikipedia.org/wiki/TI-89_series

* SDCC: http://sdcc.sourceforge.net/

[XtalJ]

I actually own a Ti-82, but I have never programmed it :-)

[znpy]

You can program it without any hardware. There is an intepreter and an "ide" on-board, look for the PRGM key.

Also, I saw there is an "ASM" command, but I didn't check if it can assemble stuff or anything.

[XtalJ]

Sounds great :-) Only problem is the "not-so-great" keyboard :-/

[NanoWar]

Make sure to check ticalc.org for your calculator community needs ;-) It is based around Texas Instruments calcs and has downloads for compilers, assemblers, utils, games, etc.