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Path: utzoo!watmath!clyde!cbosgd!ihnp4!stolaf!umn-cs!papowell
From: papowell@umn-cs.UUCP (Patrick Powell)
Newsgroups: net.space,net.arch,net.aviation
Subject: Re: Computer Technology in USSR - circa 1955 to 1970
Message-ID: <972@umn-cs.UUCP>
Date: Fri, 14-Mar-86 07:54:24 EST
Article-I.D.: umn-cs.972
Posted: Fri Mar 14 07:54:24 1986
Date-Received: Tue, 18-Mar-86 07:42:29 EST
References: <2940@gatech.CSNET>
Reply-To: papowell@umn-cs.UUCP (Patrick Powell)
Distribution: na
Organization: Computer Science Dept., U of Minn, Mpls, MN
Lines: 17
Keywords: airborne computers read-only memory ferrite transistors
Xref: watmath net.space:6499 net.arch:2849 net.aviation:2647


Ahh!!! The good old days...  Yep.  I actually have used such a beasty.
We needed to build a PDP8 based system,  and needed a ROM.  Back in those
days, you had do it with diodes,  sort of like building a gigantic
open collector NAND gate system.  Well,  I forget which maniac thought
of the idea,  but we had a 256 word core board.
We munged the sense amps,  so that they would report 1 if the core bits
were present, 0 if absent.  Then into the core boards with a needle nose
diagonal cutter.  We marked all of the core rings to be removed with
red nail polish first,  then snip!!!  away they went.
Don't!!! make a coding error.

Patrick ("Real programmers do it directly on the hardware!") Powell
-- 

(Prof.) Patrick Powell, Dept. CS, 136 Lind Hall, U. of Minn.,Minn.,MN 55455
-- Where winter is just a bad dream... 9 months long