Re: Scottish, uhm... uuh... what should we call this?

On Mon, 19 May 2008 23:01:21 +0000 (UTC),
Matt Erickson <peawee@xxxxxxxxxx> wrote in
<g0t0s1$em2$1@xxxxxxxxxxxxxxxxx>:

On 2008-05-10, Mike Andrews <mikea@xxxxxxxxxxxx> pondered onto the tubes:
Damn, but that was a _pretty_ console, especially when SCOPE was
running: the D register, arranged as a 6x8 rectangle, would have a
diagonal design moving across it all the time to show that the machine
was alive, a speaker was driven by one or more bits of the A register
for the same reason *and* to permit music to be played.

The whole 3600 was pretty, and the 3200 was in the same style.

You can see the 3600 console at
<http://mikea.ath.cx/cdc.3600.consoles.jpg>
if you like. The consoles are described in

Is that an Uncle Mike in there, a Cow-Orker, or is that a promo shot?
Also, that keyboard-thing on the left (that the guy is hunched over)
looks a lot like a miniature Hammond of the era.

That's a CDC promo shot, probably taken at the plant.

The white thingies on the front edge, by his hand, are function
selector switches which make the 3600 Do Things. See

<http://mikea.ath.cx/60021300E_3600_SysRef_Sep64.pdf>
starting on page 7-2.

The smaller switches on the almost-horizontal surface set bits in the
selected index register, the program address counter, the instruction
register, the operand bank register, the instruction bank register,
and the selected arithmetic register. or clear all of the selected
index register, selected arithmetic register, the PAC, the IBR, the
OBR, or the upper or lower instruction register opcode or operand.

The slightly-larger switches on the 45-degree surface next upwards
select which arithmetic register and which index register are shown
and set/cleared by the bit switches.

The next row up is IBR, PAC, and instruction register displays, and
the top row is OBR, selected index register, and selected arithmetic
register.

I've only been really futzing with computers since the dawn of this
century, so perhaps it's the "old computers are cool" thing, but
looking at the racks of computers at work just... lacks something
compared to the older machines with operator's desks like that. A
pull-out KVM'ed rackmount console just isn't the same.

These were, however, very simple and very slow machines: the 3600 only
had a 1 MegaFLOP instruction rate, and was considered a supercomputer
at the time. The 6600, 6400, 7600, etc., weren't more than prototype
circuits and paper machines. The 3800, IIRC, added a DAT box and
instructions for VM support; I wish I could be sure about that, but I
never got to see a reference manual for that beast, and haven't been
able to find one out on the web.

Dad works for Illinois Bell^W^WAmeritech^WSBC^Wthenewat&t, and they
used to have some rather impressive (looking) modern versions of that,
with desks in the machine room containing 4 or so 22" CRTs, filled
with status displays for the machine in front of it. $job[-1] had our
office upstairs from the machine room, with the cluster in someone
else's machine room across campus. Being brought up seeing where my
dad works, it just didn't feel right.

Yabbut those displays aren't direct indications of hardware state;
they're all indirect, derived from the state by software. Your job[-1]
was even more removed from the hardware.

The IBM 360/50 and 370/158 were the next steps in abstraction from the
3x00 in hardware display and control: the /50 had lever switches to
set bits in core or whatever register you selected, and the /158 let
you set and display the core or registers using a console KB and tube.
Later 370 gear had, and its descendants still have, the same display-
and-set facilities; the descendants use directly-attached lapdogs as
maintenance facilities.

Everything's at increasing levels of abstraction. Hell, the newer IBM
mainframes run picocode, microcode, and millicode, and the machine
definition is set by those levels of code. In LPAR mode, there are
multiple virtual images of the machine definition running under a
VM-like hypervisor. Some of the images run the operating system, but
others run IBM-provided code to let multiple OS-running images talk to
one another, manage common data, and so on. It's a _really_ strange
world inside that hardware nowadays: abstractions five or six levels
deep.

--
Bolt, clobber leading element of mob if it catches up to you,
bolt, repeat. If you run out of space to run, die. Messy. :)
Avoid mobs to begin with.
-- Thorfy, in The Other Place
.

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