HEC4 Electronic Computer

[Marvin Johnston]

While again searching for radio stuff :), I ran across this website in
Australia with an interesting article written in 1954 about the Morgan
Crucible Co. Ltd, and how they justified their purchase of the HEC4
Electronic Computer. From the first few paragraphs:

"The computer selected was the HEC4 Electronic Computer designed by the
British Tabulating Machine Co (later becoming ICT and then ICL - who
re-named it the ICT 1201), which was used with modified Hollerith
punched card equipment for I/O peripherals. Systems were designed to use
conventional 80 column punched card equipment for much processing
(sorters, collators, tabulators and reproducers). Details of this
machine are described in a second article below. Both articles were
published in the "Electronic Engineers Reference Book" for 1958. The
cost of the machine was about £30,000."

Also included are the specifications of this machine:

Specifications of ICT HEC4

  
 HEC4 Brief Specifications
 P.R.F.
                       38.4 kc/s
 Number base
                       Binary
 Mode
                       Serial
 Word Time
                       1.25 milliseconds
 Word length
                       39 and sign
 Instruction type
                       1 operand; 1 next instruction
 Magnetic Drum
                       3,000 rpm; 64 tracks; 1024 words; 
                       track switching 5 milliseconds;
  
                       18.75 milliseconds max. access
 Quick Access stores
                       2 words
 Add or Subtract
                       2.5 milliseconds
 Multiply
                       800 milliseconds max.; 240 milliseconds ave
(slow)
  
                       50 milliseconds max.; 22.5 milliseconds ave
(fast)
 Divide
                       48.75 milliseconds
 Punched cards
                       100 cards per minute (in); 100 cards per minute
(out)
 Printer
                       100 lines per minute; 100 characters per line
 Price
                       £30,000

http://www.vk2bv.org/sb/hec4.htm