Reposting, I'm a little worried these do not exist anymore. I've already
tried every reseller on the planet. Generous Bounty for any of the
HP 12920B Asynchronous Multiplexer :
12920-60001 Upper Select Code Data Board
12920-60002 Lower Select Code Data Board
12922-60001 Control Board
HP 12920A Asynchronous Multiplexer:
12921-60001 Upper Select Code Data Board
12921-60002 Lower Select Code Data Board
12922-60001 Control Board
Even single boards of any of the above would be a big help.
So, we have the ABC, Colossus, Manchester Baby, and now the EDSAC.
Anyone for the ENIAC? Univac I? IAS machine? Whirlwind?
How come 3 of the 4 are in Britain?
On 2014-Nov-29, at 9:12 PM, John Foust wrote:
> The National Museum of Computing unveils EDSAC re-creation:
On 24 November 2014 at 22:40, Holm Tiffe <holm at freibergnet.de> wrote:
> I understand that it will be very expensive to change such a "naturally
> grown" infrastructure and this is that cause that I wrote that the US
> should have changed this long before nowi, where it is really to late to do
[upgrading (the US) infrastructure]
But I'm wondering about Japan. As was mentioned by someone else
earlier, their's an example of how it shouldn't be done.
However, as part of that they already have a mix (so they're kind of
used to that) of 50Hz and 60Hz depending on where you live.. and they
use US (or as close as doesn't matter) plugs. At 100V. The whole
system is quite frustrating, and scary to look at as well.
Rickety-rackety. Reminds me of underdimensioned old 6V car wiring,
with much of the same problems (dimming, heat..).
So what I was thinking is that it should, in principle, be possible
for Japan to introduce 230V in new areas (and new areas are built
constantly), with European plugs not only to make it safer but also to
clearly make the distinction. That's something that I believe could
work in Japan, people tend to pay attention. I'm not so sure it would
work anywhere else. That's something I would like to see. Not only
because of my old linear transformer computer gear.. or the
impossibility to use my favourite bread machine (doesn't come with an
100V AC motor). 100V isn't particularly energy efficient when it comes
to distribution, and Japan needs to become much, much more energy
> Here in germany 1 phase power lines simply don't exist. The entire
> infrastructure is build with 3 phases and the phase balancing is made on
> every distribution paneel in every house. This is why it isn't a big
> problem to get a 3 phase outlet installed somewhere you need it.
> Most cables are in the ground, but on the other end of my village here
> (1km distance to the next city) there are some overhead lines with at least
> two transformers on masts that distribute 3x400V to groups of houses.
Same in Norway (I'm traveling between Norway and Japan so experience
both). Or at least in my town. The whole electricity infrastructure
was reworked completely for all of the town some years ago. Everything
moved from poles to sub-ground cabling, and 400V 3phase to every
house, and taken from there. New houses and old ones are done a bit
differently internally though.