Control Data 160

Billy Pettit bpettitx at
Wed Sep 9 15:26:13 CDT 2015

William Degan wrote:

Comparing the 160 and 160-A manuals with the 160 in the ebay auction

Page 37 of the 160 manual from 1960 -  smaller "160" marquee sign.
Page 3-1 of the 160-A marquee says "CONTROL DATA 160-A"
Ebay auction says "CONTROL DATA 160"

So, there were two variations of the 160 marquee/sign above the numeric


Also, if a person is looking at the front of the computer, on the top left
side, there is a square cut-out / slot? in the original 160 table
(purpose?).  This slot does not appear on the 160-A's table (from the 1963
programming manual), nor is it present on the Ebay auction.

I am thinking this was originally a "later" 160 that was probably serviced
well into the 160-A days.


Only a few 160s used the 3 small inserts in the marquee.  There were used to make it easier for the NCR rebrand.  The later solid sign became the CDC standard.  

The cut out on the left was for the BPRE-11 punch.  Only the early 160's and early 1604 machines had this.  The punch table was spring loaded and could be raised up to the desk top to reload paper tape.  Later on, the punch was mounted on a tray that slid out to the front.

Another change was the replacment of the original paper tape reader with the PED 350.  PED (Peripheral Equipment Division) was a CDC created company.  Their first product was the 350 reader.  Later, they made the 60X series of tape units and the 405 card reader.  This was all part of CDC's effort to move away from other companys' peripherals.  The early CDC systems shipped with Ampex tape units, IBM card equipment.

The original paper tape reader was an inport from Ferranti in England.  It was fascinating; used thyratrons as light sensors.  I had one, but it disappeared in the last move.  You can tell it from the 350 by the paper tape load arm.  On the Ferranti, it is a steel rod.  On the PED 350, it is a flattened V shaped plastic arm.

Another way to tell early 160s from later units is the side drops.  On the early units, the top formica also went down the left and right side about 12 inches.  This stopped mid-life.  Old memoriy says at s/n 43 but after 55 years, that is not hard data.

The early 1604's also had this side drop of the desk top.  You can see it in some early photographs.  I did see one 161 typewriter stand with the side drop, but don't remember if it went into production.

NO 160s were ever converted to 160-As.  Not one.  There are physical differences in the logic chassis.  More cards slots were needed.  The extra 4K bank of memory takes up a lot card space.  The front panel would have to be totally replaced.  The 160-A requires a lot more cable ports for the Buffer channel and the external memory (169).

160-A manuals would be useless for a 160.  The card types are the same and about half the commands are the same.  But that is it.

By the way, bitsavers has an excellent description of the 160 in "System Programs For The 160 Computer". It includes a photograph showing the above differences.  And pages 1 - 10 present good insight to Seymour Cray's thinking about his next machine, the 6600.  It shows where the idea for the PPUs came from.

The obsolete 160s were in use for many years after their demise.  Usually for testing peripherals, copying paper tapes, etc.  I last worked on one in 1980, almost twenty years after it was built.

Billy Pettit

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