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IBM 1130

Manufacturer IBM 1130
Identification,ID IBM 1130
Date of first manufacture1965
Number produced -
Estimated price or cost-
location in museum -
donor Robert Garner

Contents of this page:

IBM 1130 The punched paper tape unit on the 1130 may be placed elsewhere for convenience.

IBM-1130 - by Ron Mak

  1. instruction set almost identical to the IBM 1800, as per Gordon Bell

  2. see (offsite) (broken link??)
    IBM 1130 Functional Characteristics.

    IBM 1130 Functional Characteristics
    File No. 1130-01
    Order No. GA26-5881-6

  3. Box below was lifted from (I'm getting tired of URLs that go away and the information is "lost". Later corrected and enhanced by Brian Knittel - web site)
The IBM 1130 was introduced in 1965 and is considered an early third generation computer. It was a single user batch system and the primary input device was the IBM 1442 card reader which could read 300 cards per minute. The primary output device was the IBM 1132 printer which had a top speed of 80 lines per minute. Shortly after I graduated the printer was replaced with an IBM 1403 printer which had a blazingly fast top speed of 600 lines per minute. The system console, which was attached to the CPU could also be used for input and output, but this was just a modified IBM Selectric typewriter and had a top speed of 15.5 characters second. The IBM 1442 was also capable of being used as an output device and could punch 120 cards per minute.

The maximum amount of addressable memory for the IBM 1130 was 32K (16 bit words) and the system that my high school had contained only 8K. The system had only one disk drive and the disk cartridge that it used contained one platter about the size of a large pizza, capable of holding about one million characters.

All of the CPU's math was performed using the 16 bit accumulator which also had a extension of another 16 bits that could be used to handle larger computations. All of the arithmetic was done in two's complement integer mode and there was no hardware floating point. If you needed to use floating point arithmetic you had to call a software subroutine. The range of integer values for single precision integer arithmetic was -32,768 to +32,767.

The Instruction Address Register (IAR) pointed to the next instruction in memory to be executed. The CPU also had three index registers which could be used to modify the base memory address referenced by an instruction. A subset of the CPU's instruction set was used to place values into the index registers, modify them and store them.

Trying to debug a program (assembly/machine language) on the 1130 was a real chore. You had to sit at the console and single step through the instructions one by one, checking the contents of the accumulator, extension and various index registers after each step. This would not have been so bad if all of the little light bulbs in these displays were guaranteed to be working all of the time, but frequently some of them were not and you had to guess.

If you're interested, here's the instruction set:

LD    Load accumulator  (from memory)  
LDD   Load double       (accumulator and extension)
STO   Store accumulator (to memory)  
STD   Store double  
A     Add  
AD    Add double  
S     Subtract  
SD    Subtract double  
M     Multiply  
D     Divide  
AND   Boolean And  
OR    Boolean Or  
EOR   Boolean Exclusive Or  
LDX   Load index register  
MDX   Modify index register
MDM   Modify memory*
STX   Store index register  
SLA   Shift left accumulator
SLT   Shift left together (accumulator and extension)*
SLCA  Shift left and count accumulator*
SLC   Shift left together and count*
SRA   Shift right accumulator  
SRT   Shift right together*  
RTE   Rotate right (accumulator and extension)*
BSC   Branch or skip on condition  
BSI   Branch and store IAR (Instruction Address Register)
XIO   Execute input/output  
NOP   No operation*
LDS   Load Status  
STS   Store Status  
WAIT  Wait
*Each instruction used five bits to indicate the operation code, and there were actually only 24 valid operation codes. MDM (Modify Memory) was a variation of MDX (Modify Index), the left and right shift instructions used just two opcodes with modifier bits in the displacement field, and there was no specific code for NOP. Usually, a shift instruction with a count of 0 was used as NOP. The eight undefined opcodes were interpreted as WAIT.
|  Operation        |Long|Index   |     short instr: displacement |
|    Code           | Bit|Register|Ind| long  instr: modifier     |
+---+---+---+---+---+--- +---+--- +---+---+---+---+---+---+---+---+
| 0 | 1 | 2 | 3 | 4 | 5  | 6 | 7  | 8 | 9 |10 |11 |12 |13 |14 |15 |
+---+---+---+---+---+--- +---+--- +---+---+---+---+---+---+---+---+
Most instructions could be executed in "short" (16 bit instruction) or "long" (32 bit instruction) mode. If bit 5 in the instruction word was 0, the instruction was executed in "Short" mode, and the low eight bits of the instruction word were interpreted as a displacement relative to the Instruction Address Register (IAR), allowing the instruction to reference memory within -128 to +127 words of the word after the instruction itself.

If bit 5 of the instruction was 1, the instruction was executed in "Long" mode, and the effective address was taken from the second word of the instruction. In this case the low 7 bits of the first instruction word contained modifier bits, a shift count, or other data. Additionally, most long instructions could be executed in "indirect" mode which meant that the address referenced by the second word of the instruction contained the actual address (or pointer to) the actual operand. Indirect instructions were flagged by turning on bit 8 of the instruction word.

Special features

Historical Notes
  1. This was after the IBM 360 series introduction. Apparently the low end 360 series (Model 20, later model 25) did not reach this low level in pricing?

    Introduction statement from
    For release:
    A. M. 's Thursday
    February 11, 1965


    lnternational Business Machines Corporation

    C. G. Francis, Director of Information

    Data Processing Division

    112 East Post Road
    White Plains, N. Y.
    Bert Reisman
    914 WHite Plains 9-1900



    WHITE PLAINS, N. Y., Feb. 11 . . . The first IBM computer to rent for less than $1,000 a month was introduced today by International Business Machines Corporation.

    Monthly rental of the new IBM 1130 computing system begins at $695. Its internal computing ability, however, is greater than systems costing several times as much.

    The desk-sized 1130 is designed for individual use by engineers, scientists and mathematicians. But with its range of peripheral units, the 1130 also will be used in such fields as publishing, construction, finance, manufacturing and distribution.

    For ease of use by many individuals, an advanced storage technique is available with the 1130 computer. Data and instructions for computer processing are recorded on a magnetic disk similar in appearance to a phonograph record. Disks are protected by a plastic cartridge. Each IBM 2315 disk cartridge can hold the equivalent of more than one million characters of information.

    The cartridge enables an engineer, for example, to store information about his own work on his own disk. When he wishes to use the computer, he simply slides the disk with its plastic jacket into a slot on the 1130 console. Information from the disk is transferred into the 1130's high-speed core memory for processing. The computer has a memory capacity equivalent to more than 16,000 characters of information.

    The 1130 is designed for use in a wide range of scientific, technical and business activities. These include:

    • -- solving of complex mathematical and statistical problems;
    • -- preparing newspaper, magazine and book copy for automatic typesetting;
    • -- developing road, bridge and tunnel designs for civil engineers;
    • -- scheduling construction projects using critical path techniques;
    • -- analyzing geological findings to assist petroleum exploration teams;
    • -- balancing electrical load flow for public utilities, and
    • -- accounting for delivery route operations of bakeries, dairies and other distribution companies.
    To assist 1130 users in making effective use of their system, IBM will provide more than 50 application programs for use in such fields as civil engineering, publishing, mathematical and statistical problem-solving, and petroleum exploration and engineering.

    "Many small companies, research centers and development groups have a need for low-cost computing power. The 1130 can meet this need in the smallest engineering and commercial organization or in separate departments of larger corporations," John R. Opel, vice president-marketing of IBM's Data Processing Division, said. "It provides a high level of capability, but at a cost that makes it practical to bring the computer right to the Individual with a problem which must be solved," Mr. Opel said.

    The 1130 computing system employs the microelectronic circuits produced by IBM's Solid Logic Technology. These circuits, similar to those used in the IBM System/360, operate at billionth-of-a-second speeds. They enable the 1130 to perform as many as 120,000 additions in a second -- unprecedented power for a computer in this price range.

    Programs written in FORTRAN for the 1130 can be run on the IBM Sysrem/360 if there is the same type of peripheral equipment available in the System/360 configuration.

    The application programs provided without charge with the 1130, such as those for the solution of mathematical and statistical problems, will simplify use of the computer for individual engineers, business firms and consultants.

    The individual need only indicate which pre-written program he needs, supply data, and he will receive an answer within a few moments. He can communicate with the computer through its keyboard.

    Since the user does not have to tell the computer how to solve such complex problems as simultaneous equations or multiple regressions, a good deal of his time is saved.

    Information generated by the 1130 can be represented graphically with an lBM 1627 plotter linked to the computer. The plotter can prepare charts, graphs and diagrams from tabular results calculated by the computer. The plotter can thus trace the shape of a cam being designed or draw business graphs depicting trends in sales and manufacturing. A set of programs available with the computer enable it to smooth out point-to-point data and thus represent curves precisely.

    To accomplish a variety of applications ranging from research to route accounting, the 1130 can be used with paper tape punch and reader, card read punch and a low-cost printer as peripheral equipment.

    Main memory of the 1130 computing system is a magnetic core storage with capacity of 4,096 or 8,192 16-bit words. Memory cycle time -- the time required to move a word from and restore it to memory -- is 3.6 millionths of a second.

    The basic IBM 1130 computing system will rent for $695 a month and sell for $32,280. A typical system with disk storage will rent for $895 a month and will cost $41,230.

    First deliveries are scheduled to begin in the fourth quarter of 1965. The 1130 computing system will be manufactured at IBM facilities in San Jose, Calif. It also will be manufactured by the IBM World Trade Corporation in Greenock, Scotland, for customers outside the United States.

    # # #

    DPD 212-A

  2. From "Technical Information" release February 11, 1965 on
    1. Its basic configuration, with memory capacity of 4,096 16-bit words, memory cycle time of 3.6 microseconds, and a paper tape reader and punch, has a monthly rental of $695. Memory capacity can be expanded to 8,192 16-bit words.
    2. A new low-cost printer, a graphic output plotter, punched tape and punched card units broaden the application capability of the 1130 computing system.
    3. The IBM 2315 disk cartridge, ... When the cartridge is inserted in the 1130, the disk itself is engaged in two ways. A power drive causes the disk to spin at 1500 revolutions a minute. At the same time, a forked arm extends to read and write on both magnetic surfaces of the spinning disk. Programs can be transferred from the disk to the 1130's core memory at the rate of 35,000 16-bit words a second.
    4. The IBM 1627 plotter, ... One model of the 1627 provides an 11-inch wide plotting surface. It plots 300 points a second in increments of 1/100th of an inch. The second model provides 29-1/2 inches of drawing surface, and plots at 200 points a second in increments of 1/100th of an inch.
    5. The new IBM 1132 printer is the lowest-cost on-line computer printer ever announced by IBM. It rents for $275 a month. With a 48 character set, the 1132 printer can produce 80 lines of alphameric copy a minute. If numeric results of computation are desired, a numeric character set will increase printing speed to 110 lines a minute. The 1132 supplements the 15.5 character-a-second console printer and enables the computer to produce business reports comparable in appearance and content to those produced by much larger computers.

      Lou Greer, who used to sell the 1130, says the above printer may have been the worst printer ever sold by IBM - he hated them.

    6. Paper tape ... are the IBM 1054 paper tape reader and the IBM 1055 paper tape punch. ... Both the 1054 and 1055 employ the six-bit IBM standard perforated tape and transmission code with odd parity. Punching and reading speeds each are up to 14.8 characters a second.
    7. Card input and output ... two new models of the IBM 1442 card read punch.
      Model 6 reads at 300 cards a minute and punches at 80 columns a second. The rate at which cards are punched depends on the number of columns punched in each card. For faster processing of cards,
      Model 7 provides reading at 400 cards a minute and punching at 160 columns a second.
    8. Deliveries of the 1130 are scheduled to begin in the fourth quarter of 1965. The 1130 computing system will be manufactured at IBM facilities in San Jose, Calif. It also will be manufactured by the IBM World Trade Corporation in Greenock, Scotland, for customers outside the United States.

This Artifact
from the donor - Robert Garner
Our 1130 has a 2315, 1/2 million-word disk cartridge unit on the right side, behind the door. The paper tape reader was probably primarily used for booting, instead of the large, 300 cards/min 1442 card reader.

There is, as in all 1130's, a 15.5 characters/sec console printer as part of the CPU unit. A large 1132 printer at 80 lpm was available. There was also a plotter.

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Updated Dec, 2017