IP: A bit more^2 on Y2K and the past

[Dave Farber <farber () cis upenn edu>]

X-Sender: crocker () mbl edu
X-Mailer: QUALCOMM Windows Eudora Pro Version 4.0.1 
Date: Sat, 14 Nov 1998 18:25:50 -0500
To: farber () cis upenn edu, ip-sub-1 () majordomo pobox com
From: Steve Crocker <crocker () mbl edu>
Subject: Re: IP: A bit more on  Y2K and the past

> I find most interesting a comparison between the cost of storage back then 
> and today. By my rough calculations, there is a cost difference of 
> (approximately) 1,000,000 between the cost of memory in the 1970s and 
> today. Back then, core memory was priced at something like $1 per byte. 
> Today, semiconductor memory is about $1 per megabyte. The same cost 
> comparison holds between early DASD and current disks. 

In the early 1960s, the principal large machine was the IBM 7094.  It had
32K words of memory.  Each word was 36 bits.  This works out to slightly
more than 1,000,000 bits (not bytes) of memory.  The memory was bathed in
an oil bath and heated (not cooled) slightly above room temperature.  The
memory unit alone cost $1M, which works out to $1/bit.

[ The 7094 the successor to the 7090 (AKA 709T) the successor to the 709 -- a vacumn tube machine like the 704, used 
cores that were initially hand threaded in Singapore if my memory is correct. The 7090 used air cooled core but to get 
the speed up in the 7094 they went into oil. It used to be real fun to see the white shirted tie wearing IBM Customer 
Engineers working on the memory. That entailed lifting the core planes out of the oil bath - yuke!!. BTW the 7094 last 
one very important feature of the 7090 memory. I used to keep my lunch warm by putting it in the memory box (air 
cooled). djf]

In the early 1970s, we all cheered when memory for PDP-11s fell just under
$.01/bit.

Memory was indeed much dearer then.

Steve

----------------------------------
Steve Crocker Associates                        Bus:   +1 301 654 4569
5110 Edgemoor Lane                              Fax:   +1 202 478 0458
Bethesda, MD 20814                              crocker () mbl edu