TI 990 architecture / was Re: TI-99/4A Floppies

[Liam Proven]

On 02/10/2007, Allison <ajp166 at bellatlantic.net> wrote:

> The 9900 chips is not crippled, for 1976 three voltage NMOS its about as fast
> as the technology of the time could go.  The TI99/4 did however do a nasty to
> it. One is they muxed the bus down to 8bits wide and that does slow the system
> some. There were 128 words of ram (6810s) that if you execute there the speed
> is noticeable.  The other is the GROM (sort of an interpreted language with a
> register point to next instruction) is a bottleneck as well.  There was a
> later 9980 and the 9985 which were a 8bit bus interface and were somewhat
> crippled but I'd never seen one in a TI99/4A.

That's probably true, but the 99/4a wasn't a 1976 machine. It was
released in 1981 and withdrawn 1983. A bit unfairly for a tweaked 1979
machine (the 99/a), the 99/4a's competition was mainly 1982 machines
like the Commodore 64 and Sinclair Spectrum, which (based on my
possibly erroneous recollection) outperformed the 99/4a significantly.

-- 
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