15 Nov
2010
15 Nov
'10
11:41 p.m.
Tony writes:
Tim writes:
> Having worked with 1103's I would argue that by modern standards
> Even the "cream of the crop" were little above floor sweepings.
Was it that a lot of new 1103s were DOA, oe what there
a problem with
them fialing in use, or what?
The reason I ask is that I have several old HP
calculators full of 1103s,
and AFAIK all are original (and gettign on for 40 years old). So far,
otuch wood, I've not had any problems with the RAM in these machines.
How many hundreds of 1103's are in each HP calculator? :-)
In the early minicomputer 1103-based memories (say 16Kbytes, so
128 1103 chips) it was, um, optimistic to expect a lot of stability.
In the bigger "supermini" systems (say 128 Kbytes, so over a
thousand 1103 chips) ECC was a necessity and continual scrubbing
helped a lot with stability - but that was a lot of work and power
consumption just to brag that you had semiconductor memory,
and the advantages over core were not all that obvious.
I'd expect that smaller systems probably didn't have ECC or scrubbing
but also didn't have high expected uptime. Were 1103's in the HP 9830?
I had a couple but they usually worked fine enough that I never had
to go rummaging through the insides.
My feeling is that in the 1103 era (which preceded my direct
involvement but I inherited several 1103-based systems), DRAM chips
were not quite ready for prime time. By the time the 4116 came
along things had settled down and a lot had been learned from
the 1103 and DRAM really was ready for prime time.
Tim.