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

  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. 


Gas-filled tubes driving the hammers.


Power supply.

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