11 Apr
2013
11 Apr
'13
5:55 p.m.
Tony Duell wrote:
To be fair, using the paged mode in DRAMs you got two bits out nearly as
fast as one. I imagine this project was related to the SEQ pin in a
certain processor, though I have no idea if one inspired the other or if
they both came out of the same set of "underground" experiments.
The Macintosh SE used the same trick to fetch 32 bits at a time for the
video, half as many times as older models. This more complicated change
only resulted in half the improvement they could have gotten from a
trivial redesign to make use of 1987 DRAM chips:
http://www.merlintec.com/lsi/mac512.html
-- Jecel
[TI99/4A]
I have one, and can imagine how nice it would have been with 16KW of
internal RAM.
Back in 1980 I got to use a TMS9900 based computer from Fluke for a few
months. I have never found any information at all about this machine on
the web, but it really showed off the performance that you could get
But crippled by a very inefficient design and
implementation - is that
Yes, I think that's a resaonable way of putting it. from this processor. It had a built-in wide screen CRT
with a touch
screen and besides the floppy drive it had a 128KB bubble memory
"disk"
and a nice GPIB interface. It was in the "sewing machine" form factor
and might have come out before the Osborn-1.
Ah, searching for "Fluke instrument TMS9900 GPIB" instead of "Fluke
computer" got me several manuals for the Fluke 1722A at archive.org,
which is the computer I remembered. The manuals are from 1983 and 1984,
but I am 100% sure I used it in early 1981.
fair? A bit
like several 1990s Macs, with 32-bit processors on
multiplexed 16-bit buses, yielding cheap logic boards but dire
performance.
I suspect you'll know this, but which 1980s (8 bit) microcomptuer had
4-bit wide RAM at the hardware level? (The hardware did 2 memory cycles
to make up an 8 bit byte ot give to the processor).