Mailinglist Archive: opensuse (4020 mails)
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Re: [SLE] new v9.2 is out-terminal question
- From: Richard <ratcheson@xxxxxxxxxxxxx>
- Date: Wed, 27 Oct 2004 14:47:33 -0500
- Message-id: <200410271447.33161.ratcheson@xxxxxxxxxxxxx>
On Wednesday 27 October 2004 01:20 pm, Darrell Cormier wrote:
> > Just curious if any of you have every worked with a machine that used
> > core memory. If I remember correctly you basically had a cage of
> > "boards". Each board was an x-y grid of fine wire and around each
> > intersection of the wires was a ring of some ferrous oxide material.
> > A current was applied to a certain x-y coordinate to charge the ring
> > thus representing a binary 1. This was a system that had a destructive
> > read which required you to write back what you just read.
> >
> > I have never used one myself but one of my college instructors had one
> > of these cages of core memory modules from a machine he had used in
> > his youth. Quite interesting.
Yep, worked on a lot of them between '60 to '74. Neatest one was a
drum/core machine which was actually dc digital as opposed to ac digital.
DC used flip-flops which gave a 1 when low and a 0 when hi. With ac you
had to use a strobe to see what the state was at any particular time. The
innards of hard drives use the same methods to read data off the heads
before they are convertted to dc levels.
The drum/core machine used 16k of core and had drum storage up to 500 megs
or so. One of those machines was the first Timeshare used by NASDAQ back
in the late 60's early 70's. It had an exec routine, now they are called
an OS, that broke the core into several sections and could run multiple
programs by swapping segments out to dedicated parts of the drum. In the
late 70's someone, IBM I think, reinvented that wheel and called it
virtual memory which is now used in all ps systems.
BTW, the 16k referred to the number of 32 bit words it could handle. MOst
of the stuff we played with was done in octal cause it was so easy to
translate from decimal. Hex was pretty much an IBM thing.
I guess the point of all this is that there isn't anything really new under
the sun, just different ways of packaging and naming. Of course modern
computers have much more speed and capacity but still can only add and
subtract, and there are those that will make an argument that they can
only add since the other functions are successive additions.
Most mini and scientific computers into the late 70's used core and various
forms of mass storage such as tape and drum and disc.
Regarding the use of Fortran, it was still being used in the Simulation
industry into the 90's when I left that field. Since simulation is
nothing more than a lot of math calculations, Fortran was an excellent
choice of languages.
If anyone is curious about the foregoing I'd be happy to discuss this off
the list or on the OT list.
Regards,
Richard
--
Old age ain't for Sissies!
> > Just curious if any of you have every worked with a machine that used
> > core memory. If I remember correctly you basically had a cage of
> > "boards". Each board was an x-y grid of fine wire and around each
> > intersection of the wires was a ring of some ferrous oxide material.
> > A current was applied to a certain x-y coordinate to charge the ring
> > thus representing a binary 1. This was a system that had a destructive
> > read which required you to write back what you just read.
> >
> > I have never used one myself but one of my college instructors had one
> > of these cages of core memory modules from a machine he had used in
> > his youth. Quite interesting.
Yep, worked on a lot of them between '60 to '74. Neatest one was a
drum/core machine which was actually dc digital as opposed to ac digital.
DC used flip-flops which gave a 1 when low and a 0 when hi. With ac you
had to use a strobe to see what the state was at any particular time. The
innards of hard drives use the same methods to read data off the heads
before they are convertted to dc levels.
The drum/core machine used 16k of core and had drum storage up to 500 megs
or so. One of those machines was the first Timeshare used by NASDAQ back
in the late 60's early 70's. It had an exec routine, now they are called
an OS, that broke the core into several sections and could run multiple
programs by swapping segments out to dedicated parts of the drum. In the
late 70's someone, IBM I think, reinvented that wheel and called it
virtual memory which is now used in all ps systems.
BTW, the 16k referred to the number of 32 bit words it could handle. MOst
of the stuff we played with was done in octal cause it was so easy to
translate from decimal. Hex was pretty much an IBM thing.
I guess the point of all this is that there isn't anything really new under
the sun, just different ways of packaging and naming. Of course modern
computers have much more speed and capacity but still can only add and
subtract, and there are those that will make an argument that they can
only add since the other functions are successive additions.
Most mini and scientific computers into the late 70's used core and various
forms of mass storage such as tape and drum and disc.
Regarding the use of Fortran, it was still being used in the Simulation
industry into the 90's when I left that field. Since simulation is
nothing more than a lot of math calculations, Fortran was an excellent
choice of languages.
If anyone is curious about the foregoing I'd be happy to discuss this off
the list or on the OT list.
Regards,
Richard
--
Old age ain't for Sissies!
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