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The LINC had 2048 , 12-bit words of memory in two sections. Only the first 1024 words were usable for program execution. The second section of memory could only be used for data. Originally the LINC had a 12 bit accumulator, a 1 bit link register, and a 10 bit instruction location register (program counter). The first sixteen locations in program memory had special functions. Location 0 supported the single-level of subroutine call, automatically being updated with a return address on every jump instruction. The next fiftenn locations could be directly addressed by certain instruction to hold data or to work as index registers. Special read-only registers were provided to read control panel switches (left and right switches), and a read/write register controlled six relays intended for use by external instruments. [1]

A later version of the LINC added a 12 bit Z register to facilitate extended precision arithmetic and to support interrupt handling. A single interrupt was provided, with the address of the interrupt routine stored in memory location 17 (decimal).

Alphanumeric input/output devices included a dedicated keyboard, and the ability to display text on the attached bit-mapped CRT. A teleprinter could be connected for printed output.

Arithmetic was 1's complement, which meant that there were representations for "plus zero" and "minus zero".

The original LINK required 8 microseconds for each instruction.

Instruction set[edit]

The natural notation used for the LINC was octal. In this section, all numbers are given as base 10 unless identified as octal. The LINC instruction set was designed for ease of use with scientific instruments or custom experimental apparatus.

  • Miscellaneous class, no address - Halt, clear accumulator, enable tape mark write gate,

transfer accumulator to relay register, read realy register to accumulator, no operation , complement accumulator

  • Shift class, no address (all operate on the accumulator and optionally the link bit), rotate left, rotate right, scale right (replicates sign bit),
  • Full address class, two word instructions. immediate address given in second 12-bit word of the opcode, add, store and clear accumulator, jump. Only the first 1024 words of memory can be accessed.
  • Skip class, skips the next instruction, can test for set or clear condition. Conditions are: external logic line (1`14 linput l ines coudl be tested), key struck, sone of ficvbe sens switches , accumulator positive, link bit zero, or active tape unit in an interblock zone. Later models added skip on bit 0 of the Z register, skip on overflow, and skip on interrupt paused.
  • Index class - these instructions could either have a second word that was the immediate operand, or that specified the operand address, or that specified one of the registers 01 through 15 (decimal) as holding the address of the operand. The address was incremented. These instructions included load or add to accumulator, add accumulator to memory , add accumulator with carry to memory, multiply (producing a 22 bit signed product), skip if equal, skip and rotate, bit clear, bit set, and bit complement. Another instruction in this group was to display a bit map, to represent a character or other data, on the built-in CRT display screen.
  • Half-word class - instructions operating on the lower or upper six bits of a word. These included load half, store half, skip if halves are different,
  • Set - moves data from any memory location to one of the locations 1 through 15.
  • Sample - reads one of the sixteen 8-bit analog to digital converters and places the signed value in the accumulator. The first eight A/D channels were dedicated to control panel knobs to allow interaction with a running program by the user. The instruction could either hold the computer till a conversion result was ready, or allow more instructions to be executed provided they didn't rely on the contents of the accumulator, which would overwritten by teh A/D conversion value.
  • Display - draws a pixel on one of the CRT displays at a specified location, optionally indexing a register.
  • Index and skip - adds one to one of the memory locations 1 through 15, and skips if a 10-bit overflow occurs.
  • Operate class, used for input/output operations. These included set a bit on one of 14 output lines, read the keyboard, or read the left or right switch bank.
  • Tape class, with opcodes to position the tape, read or write to the tape, and to check the tape against memory.


In addition to the original "classic" LINC, slight programming variations occured when using the Micro-LINC, Micro-LINC 300, and LINC-8. There were variations in the input/output equipment, access to memory. Later models had a faster clock speed.

Editor retention[edit]

I can make your Wikipedia existence miserable while staying strictly within policies and not using my admin tools. --Ymblanter (talk) 18:37, 14 March 2015 (UTC)

Yes. Yes they can. Stanford prison experiment.

Vacuum engineering needs some expansion[edit]

Year Vacuum (Pascal) 16th c 3x10^4 Mine water pumps 1880 10^-1 Sprengle pumps, Edison bulbs 1905 10^-2 Gaede rotary mercury pump 1950's 10^-5 1958 10^-10 10^-12 (experimental)

Nobody loves you unless you play soccer[edit]

John Wesley Cockburn (January 9, 1856-November 9, 1924) was a Canadian engineer, entrepreneur and City of Winnipeg alderman. He was responsible for securing development rights on the Winnipeg River to allow the city to build a hydroelectric generating station.[2]

Born in Thorold, Ontario in 1856, Cockburn studied mechanical engineering and worked at hydroelectric developments at Niagara Falls and on the Welland Canal. In 1882 he came to Winnipeg while working for the Canadian Pacific Railway. With a partner, he operated a general store and grocery in Winnipeg. In 1891-1892 he served as a city alderman, and was reelected in 1901 through to 1907.[2]

  1. ^ Mary Allen Wilkes, Wesley A. Clarke, Programming the LINC Second Edition, Computer Systems Laboratory, Washington University, 1969
  2. ^ a b