10 worst computers of all time

On 2013 Apr 9, at 5:41 PM, Liam Proven wrote: The "registers in external (D)RAM" was not a problem, that was a characteristic (and feature) of the predecessor TI 990 minicomputer architecture. It meant the instruction set had the efficiency of a very orthogonal set of 16 registers to work with, but didn't have to save & restore those registers across function call & return, you just changed the workspace pointer and had a whole new set of registers. This was great for modern stack-based languages and for process context-switching (if you were doing that). It was far nicer than a two-accumulator architecture such as the 6502 or the mish-mash register set of the 8080/Z80. I worked with the 990 mini and 9900 microprocs at the instruction level and, in that regard (and as much as I remember), I liked the arch. more than the PDP-11. I didn't directly work with the TI-99/4 but from what I read the problem with it was it took what was a lovely 16-bit microprocessor and embedded it in a crippled memory/support environment. Apparently only a few hundred words of RAM were directly on the processor bus - that mem being intended for the workspace/registers (and presumably this actually was static ram, not DRAM) - while the majority of RAM was accessed through a slower, secondary, 8-bit bus.