Just found schematics to a Tube Mini! 1958! WOW!

From: John B <dylanb_at_sympatico.ca>
Date: Wed Nov 24 10:30:50 1999

This unit is not listed anywhere on the web and have not found it in the
list of Digital Computers (though I can't find the page I usually look at).

In going through my PDP-8 stuff I found a book called "RCL".

This *mini* was built in 1958.

I uses delay line memory, has a number of mini-computer functions (many tube
flip flops) and it's programmed with wires (i think). It has a bulb front
panel with some program control switches.

Interfaced to it was a printer and a CRT (maybe more, I am just getting
through the memory control schematics).

Its memory control system contains:

Set address, decimal decoder, subtract 1, read , add, write (all
these three have many other function control flip flops), address overflow,
decode, print, carry, add+1, end storage...

Address system is 8 bit. (256 bits of address space)

OOOOOOOOOOOOOO.. (just flipped the page) it *does* have a core memory array.
(5 stages X 256 bit)

OOOOOOOOOOOOoo (just flipped the page again)... It has a 16 bit A/D
converter (tubes)

(sorry but OOOOOOOOOO - just flipped the,,,,,....) it has a data register ..
Ahhh, this is a 16 bit mini, with core (just found more core memory)

Getting an instruction set here - (so far):

Add +1
Add -1 (subtract)
Add with carry
reset (jump?)

next page - A/D unit (yikes!) many tubes.....

CRT display (uses delay line memory ... I think.. if not , no idea yet)

Power supply is nasty

printer control modules - yuck!

Okay, indicator panel (found it) has: 16 bit data bus, 8 bit address bus
(light bulbs)

Programming - weird, user has access to core memory, has "START, RESET
switches), it has a *really weird* tube for "real time".. looks to be a
cesium tube or delay tube... many sensors for "real time"

more programming instructions:

clear to zero

I thought at first this unit was a counter but I see a whole programming
area with different op codes, two types of storage and a printer with CRT.
This should qualify as a *kind* of mini... It was meant to work with A/D and
D/A with some coded instructions in core memory/wires.

Anyone hear of such a unit?

Part of it is called "multichannel analyzer" but that is only the a/d
subsystem. I only have the schematics so I have to figure stuff out from

Received on Wed Nov 24 1999 - 10:30:50 GMT

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