23 Feb
2014
23 Feb
'14
5:07 a.m.
The one I got came from a TV studio (TSW
http://en.wikipedia.org/wiki/Television_South_West) it came uncased in
a cardboard box, they had apparently used it for some local show and
had uncased it to fit into the set somehow. Not switched it on yet.
Dave Caroline
On 23/02/2014, Liam Proven <lproven at gmail.com> wrote:
On 22 February 2014 21:36, Terry Stewart <terry at
webweavers.co.nz> wrote:
and here is how I've described it on the
collections page:
http://www.classic-computers.org.nz/collection/ti99-4a.htm
Nice articles and an impressive restoration!
I am not sure I've got the details right, but the significance of the
weird CPU of the TI99/4a might be worthy of a mention.
AIUI it was a low-end (single-chip?) version of an existing CPU, which
TI also used in much larger machines, right up to minicomputers.
Possibly the 99/4a's version was the first VLSI version or something.
(So a comparison with the PowerPC chip there - a single-chip
implementation of the IBM POWER architecture, an expensive multi-chip
UNIX server/workstation processor.) Also arguably bears comparison
with the BK Elektronica - that Soviet home-micro PDP-11.
But yes, as you say, the first 16-bit home micro - but very slow, in
fact slower than most 8-bits of its time period. AIUI part of the
reason for this is that the 99/4a CPU has no registers of its own,
uniquely among microprocessors - the registers are kept in main RAM,
meaning very slow bus accesses for /everything./
--
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