Acorn Electron ( A kind of cut-down BBC Micro) .
6502 CPU, built in BASIC interpreter, with assembler. And an infinity of bolt-on expansions, with lots of additional hardware added on.
I added a hard drive, but had to write the software to actually make much use of it. Which at least forced me to learn about handling data files and arrays and such like bits of exotic coding. ( Well it was exotic to me then - early 1980s).
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