Comment by PaulHoule
20 hours ago
Well, it has 256 bytes of RAM which is basically a really big register file, and everything else goes in the 16kb of "video RAM" which you can read and write by poking at I/O registers. So it is not easy to program.
It's arguably the only 8-bit computer which has a really different architecture from the others. You could otherwise imagine pulling the SID chip off a C-64 and putting it on a TRS-80 Color Computer etc.
Sharing the main RAM with video was a weak point in computers of that time period because the video system stole many of the memory access cycles. Some recent retrocomputers that revisit that period like
https://www.c64-wiki.com/wiki/Commander_X16
have a full-size memory bank and a video RAM memory bank which is accessed through a port which can be pretty efficient because you can auto-incremement the address register and just write 1 byte to the port to write 1 byte to video RAM and repeat.
Well I mean it fits in with the 8-bit era machines as far as performance but that CPU was absolutely 16 bit.
16-bit registers, operations, etc. yeah. A bigger machine of the TM9 series would be more like a PDP-11.
In fact it was a miniaturized TI-990 minicomputer: https://en.wikipedia.org/wiki/TI-990