jfp@gatech.CSNET (John Passafiume) (03/07/86)
I have been talking to an individual who spent a considerable length of
term working in research labs in the USSR on airborne computer projects.
In our discussions he mentioned some technogies and uses of technologies
that I was unaware of. For example, he discussed the use of core memories
as ROM where "little old ladies" wired the application program bits into
the ROMs. The
use of core memory as ROM is something I am not aware of. Is anyone out
there aware of such a use of core memory. He also mentioned the use of
memory plates with ultrasonic drilling of small holes for the bits (to
be used in RAM). Is there a US counterpart to this?
Finally, he indicated that they used ferrite transistors. I was not
aware of this either. Can anyone shed light on this??
If anyone can point me to any historical references to this era in either
US or USSR developments it would be greatly appreciated.
--
John Passafiume
School of ICS, Georgia Tech, Atlanta GA 30332
CSNet: JFP @ GATech ARPA: JFP.GATech @ CSNet-Relay
uucp: ...!{akgua,allegra,rlgvax,sb1,unmvax,ulysses,ut-sally}!gatech!jfphenry@utzoo.UUCP (Henry Spencer) (03/08/86)
> ...the use of core memories > as ROM where "little old ladies" wired the application program bits into > the ROMs. The use of core memory as ROM is something I am not aware of. > Is anyone out there aware of such a use of core memory. This was common in specialized applications some years ago. The on-board computers of the Apollo spacecraft used program ROMs built this way, for example. DEC's "PDP-16" (sort of a kit for building specialized computers) included a wire-your-own-ROM module of this type. I think some of the telephone switching computers may have used it also. Given these examples, I would expect that it was used quite a bit in avionics and the like. > He also mentioned the use of > memory plates with ultrasonic drilling of small holes for the bits (to > be used in RAM). Is there a US counterpart to this? If you mean ROM rather than RAM, there are a few. The 360 series used a wide variety of strange ROM technologies for their microcode, including one where the ROM was a sort of aluminized punchcard. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry
knudsen@ihwpt.UUCP (mike knudsen) (03/08/86)
> I have been talking to an individual who spent a considerable length of > term working in research labs in the USSR on airborne computer projects. > In our discussions he mentioned some technogies and uses of technologies > that I was unaware of. For example, he discussed the use of core memories > as ROM where "little old ladies" wired the application program bits into > the ROMs. The > use of core memory as ROM is something I am not aware of. Is anyone out > there aware of such a use of core memory. He also mentioned the use of > memory plates with ultrasonic drilling of small holes for the bits (to > be used in RAM). Is there a US counterpart to this? > Finally, he indicated that they used ferrite transistors. I was not > aware of this either. Can anyone shed light on this?? > If anyone can point me to any historical references to this era in either > US or USSR developments it would be greatly appreciated. > -- > John Passafiume > uucp: ...!{akgua,allegra,rlgvax,sb1,unmvax,ulysses,ut-sally}!gatech!jfp I don't think there's anything unique here, but these technologies are a bit obscure. I remember reading (probably in Bell & Newell's "Computer Structures" text) that one of the computers in the Apollo spacecraft used a "wire rope ROM" like the Russian item you described. An address de-mux shot a pulse down one of many wires (one per address). There was one big core donut for each bit in the word. If that address wire went thru toroid #5, then bit 5 of that addressed word was a ONE. A very reliable technology, and very radiation, glitch, and temperature proof. I almost used it in a home project. I suspect there are several on the Moon today! Bell Labs used various ferrite sheet and "twistor" schemes for both RAM (sort of like core) and ROM in the original ESS processors (computerized telephone exchanges) in the 60's and early 70's. The ROMs were steel sheets with little spots of north or south magnetism, which biased ferrite cores in the reading frame into which they were inserted. These cores were read like usual core RAMs. We had "ROM burners" that were big machines that fed these sheets thru and magnetized them. All this neat stuff has long since been scrapped for plain old DRAM chips. These schemes work very well -- just a bit bulky and heavy by today's standards, but pretty solid against radiation and EMP and power glitches in a military plane. mike k
darrelj@sdcrdcf.UUCP (Darrel VanBuer) (03/09/86)
Re: assorted odd ROM technologies in USSR:
The IBM 360 series used almost every conceivable scheme possible for
implementing a ROM accross the series. This resulted from both the
incredibly broad performance range of the series and that each model was
designed by a different unit within IBM. There certainly were some with
custom threaded magnetic cores. Another used capacitors printed on a sheet
with the plate punched out to create a bit.
It sounds like the Russians may have had a few novel twists, but basically
they are simply stuck with technology a decade behind US/Japan.
--
Darrel J. Van Buer, PhD
System Development Corp.
2525 Colorado Ave
Santa Monica, CA 90406
(213)820-4111 x5449
...{allegra,burdvax,cbosgd,hplabs,ihnp4,orstcs,sdcsvax,ucla-cs,akgua}
!sdcrdcf!darrelj
VANBUER@USC-ECL.ARPApapowell@umn-cs.UUCP (Patrick Powell) (03/14/86)
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 longjohn@anasazi.UUCP (03/15/86)
In article <6479@utzoo.UUCP> henry@utzoo.UUCP (Henry Spencer) writes: >> ...the use of core memories >> as ROM where "little old ladies" wired the application program bits into >> the ROMs. The use of core memory as ROM is something I am not aware of. >> Is anyone out there aware of such a use of core memory. The microdata 1600 was often shipped to the customer with the program stored in core. While it really was writable, it was functionally a "core ROM" in that nobody ever wrote it more than once. -- John Moore (NJ7E/XE1HDO) {decvax|ihnp4|hao}!noao!terak!anasazi!john {hao!noao|decvax|ihnp4|seismo}!terak!anasazi!john terak!anasazi!john@SEISMO.CSS.GOV (602) 861-7607 (day or evening) 7525 Clearwater Pkwy, Paradise Valley, AZ, 85253 (Home Address) The opinions expressed here are obviously not mine, so they must be someone else's.