Japanese computers

Jules Richardson julesrichardsonuk at yahoo.co.uk
Sat Oct 29 10:14:51 CDT 2005


Allison wrote:
>>Subject: Re: Japanese computers
>>  From: Jules Richardson <julesrichardsonuk at yahoo.co.uk>
>>  Date: Sat, 29 Oct 2005 14:11:24 +0100
>>    To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
>>
>>William Donzelli wrote:
>>
>>>>I'll see if I can find them when I get back to the UK and scan any 
>>>>interesting bits in.
>>>
>>>
>>>I am specifically looking for info on the parametron computers of the late
>>>1950s, and the Hitachi AS/6 (may be called a HITAC in a Japanese
>>>context) of the late 1970s.
>>
>>I'm almost certain there was some mention of Parametron, amongst others. 
>>Probably way too early for HITAC. I seem to recall an article about a 
>>project to build a one mega-word memory unit too, which I suppose was a 
>>rather impressive size for then (particularly if you wanted to make it 
>>reliable!). Our machines of that era are all around the 4KW mark...
>  
> 4KW was common but even the TX2 was far larger than that and that was
> pretty early transistor machine.  By mid 60s machine of size were in 
> the 16-64KW range.  Keep in mind even the designers of the time understood
> that large reasonably fast randomly accessable memory was a factor in
> computational speed and overall perfomance.

This was 1MW though, so a significant leap forward. Plus I'm pretty sure 
it *wasn't* magnetic core either. I can't remember the date range of the 
magazines we have, but they're somewhere in the range of mid 50's to mid 
60's I believe.

Presumably, alongside any real applications, it was built to showcase 
Japanese electronics of the era, and also to provide a testbed into the 
reliability of whatever technology was used on a large scale.

> As to large memories by 1962 it was well understood the real problem was
> heat, power and consistancy of the magnetics and they were well on the way
> to a good handle on those.  The main enemy was cost. Core was expensive
> per bit.

See above - no magnetics from what I can recall. Cost / heat / power 
must still have been major considerations though!

cheers

Jules



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