The Univac Solid State Computer 90, The high speed Printer.

The Printer.

The High Speed Printer could print each second 10 lines of 130 characters on chain-forms. 
The data had to be represented in the Remington-Rand-code.
There were 51 printable symbols: 10 numbers, 26 uppercase characters and 15 symbols         , . + - ( ) : # / * % ; $ & ! 
The printmechanism existed of a horizontal rigid drum, spinning ten times a second, 
existing of 130 wheels with each 51 printable symbols in a positive relief. 
Behind the character-wheels there were 130 electro-magnetical actuated hammers, powered by 130 gas-filled tubes. 
The paper was fed through between the hammers and the wheels together with the vertically moving ribbon. 
Each hammer could be fired once during a character-drum-revolution and then impressed ribbon, paper and symbol, 
leaving that character-image on the paper that just passed by on the rotating cilinder.


                               The print-cilinder without the ribbon 

A (very) simple program-part to print a result was:
  a      ic    M      C 
0213 70 4025 0228   Add (m) to (rA)					=Calculate sum
0229 67 0200 0200   On overflow: stop				=Stop
0228 17 0000 0231   Translate (rA) into RR-code		=Translate result to printable characters
0231 62 0000 0235   Take away the leading zero's		=Zero suppress
0235 60 3165 0367   Transfer rA > m					=move upper part RRcode to printer-interlace address
0367 65 3170 0372   Transfer rX > m					=move lower part RRcode to printer-interlace address
0372 27 0376 0372   Test printer: no : loop				=test printer ready
0372 11 3001 0201   Print a line from 3000-band			=print line

The printer-instructions were:
11 bbnn c : Advance paper nn lines, then print data from band bb.
16 00nn c : Advance paper nn lines only.
27 yes no : Test the printer free, ready with printing the last line.


 

     Switches on the printer-console   were: 

CARRIAGE OUT :		Pressed to open the printermechanism to insert new paper.
CARRIAGE IN  :		Made the print-mechanism to move inwards, ready to print.
CHANGE RIBBON:		Forced the ribbon to wind so it could be changed.
SPACE PAPER  :		Advanced the paper one line, to position a form.
SYSTEM OFF NORMAL - CLEAR:	to reset all off normal indicators.
RUN and STOP:		the same as RUN & STOP on the processor panel, to start or to halt a program.

And the lamps: 
CHARGE CHECK,   NO RIBBON,   NO PAPER,   CODE WHEEL,   AIR FLOW,   INTERLOCK and   OVERHEAT indicated hardware failures. 
 

Chainform.	Gas-filled tubes driving the hammers.
Rectiviers.	Power supply.

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