The following are excerpts from the December 30, 1958 7090 product announcement package.

IBM 7090 Data Processing System

The 7090 is a transistorized data processing system which is functionally the same as the 709. It is a high speed system which contains all the features of the 709. Some of the new features are:

  1. Computes five times faster than IBM 709 system.
  2. Eight input/output data channels.
  3. High speed magnetic tape units.
  4. Intermixing of IBM 729-II and 729-IV Magnetic Tape Units.
  5. Automatic priority processing using data channel trap.
  6. Separate operator's console for centralized control.
  7. New transistor circuits provide speed and reliability.
  8. New high speed core storage.
  9. New packaging for better space utilization.
  10. Costs less to install and operate than IBM 709 system.

Compatibility with other IBM systems has been vigorously maintained in the design of the IBM 7090. Retraining and reprogramming costs are minimized because of:

  1. Direct program compatibility with the IBM 709 system.
  2. Compatibility feature for IBM 704 programs.
  3. Input/output compatibility with all IBM Data Processing Systems.

Because the IBM 7090 is a direct improvement of the IBM 709, the customer will continue to benefit from the following features:

  1. Efficiency of parallel binary logic.
  2. Built-in floating point arithmetic.
  3. No-lost-time indexing.
  4. Computing simultaneous with multiple input/output operations under automatic control.
  5. Convert instructions enable efficient execution of commercial applications.
  6. Designed for use with real-time input/output.
  7. Indirect addressing, including data channel commands.
  8. Full word of sense indicators.
Units of the 7090 Data Processing System
Name Machine Model
Card Reader 711 2
Printer 716 1
Card Punch 721 1
Magnetic Tape Unit (15 Kc.) 729 II
Magnetic Tape Unit (62.5 Kc.) 729 IV
Console Control Unit 7151 1
Core Storage (32,768 words) 7302 1
Central Processing Unit 7100 1
Multiplexor 7606 1
Data Channel (Tape and Card) 7607 1
Data Channel (Tape) 7607 2
Power Converter 7608 1

A minimum 7090 System must include one each of the following units:*

Name Machine Model
Card Reader 711 2
Printer 716 1
Console Control Unit 7151 1
Core Storage 7302 1
Central Processing Unit 7100 1
Multiplexor 7606 1
Data Channel 7607 1
Power Converter 7608 1

*Data Channels and Input/Output units may be added as desired.

IBM 7100 Central Processing Unit

Function: The 7100 Central Processing Unit contains the arithmetic and stored program control circuits for the 7090 system.

Operation: Computation is in the very efficient binary arithmetic, and as with most internal operations, is accomplished in parallel in a 36-bit fixed word length. Instructions are provided to simplify the conversion for decimal or other coded input-output.

More than 200 different operational instructions are provided. They include: fixed-point arithmetic operations, floating-point arithmetic operations, logical operations on information in registers and storage, control and testing operations, input-output operations, shifting operations, and numerous indexing operations. Also provided are instructions for number system conversion and automatic table look-up operations, instruction for facilitating compiling and interpreting, variable length multiplication and division, thirty-six internal sense indicators to provide program flexibility, indirect addressing to facilitate program writing of sub-routines, and automatic floating-point overflow-underflow trap. In addition, control for independent data transmission is provided, permitting concurrent data transmission and computation without logical interference with the computer.

Arithmetic section: This section of the central processing unit consists of a storage register, an accumulator register, and a multiplier-quotient register, each with a capacity of 35 bits and sign; and a 36-bit sense indicator register. The accumulator register has, in addition, two overflow positions. The accumulator and multiplier-quotient registers are coupled when multiplying or dividing to store a 70-bit product or dividend and may also be coupled together to shift information left or right.

Index registers: Three index registers provide automatic indexing facilities, and make possible automatic address modification and loop control within programs. All three index registers have 15 positions.

Automatic priority processing: The data channel trap feature gives the programmer a valuable tool with which to control input-output operation. The data channel is allowed to signal the central processing unit upon completion of an input-output operation or an error condition. The program may then provide for further input-output operation without complex timing conditions or proceed to a corrective action.

Speed: Typical execution times for instructions (including storage reference) are: fixed point; Add — 4.8 microseconds, multiply — 4.8 to 48 microseconds (depending on the number of consecutive zeros in multiplier), divide — 48 microseconds. Floating point; Add — 16.8 microseconds, multiply — 16.8 to 40.8 microseconds (depending on the number of consecutive zeros in the multiplier), divide — 43.2 microseconds. Most logical operations take 4.8 microseconds.


Compatibility and programming

IBM 7151 Console Control Unit

The 7151 is a separate unit which provides centralized control of the 7090 system. The 7151 contains indicators, switches, keys and register displays. Channel indicators are provided and the register displays have been grouped for the operator's convenience. Information in any storage location or register can be displayed and/or changed by manual insertion through the entry keys and switches.

IBM 7302 Core Storage

The 7302 contains 32,768 words of high speed magnetic core storage. Random access to any of the 36-bit words requires only 2.4 microseconds. This includes the time to execute a complete read and rewrite cycle. All 32,768 storage locations are directly addressable.

IBM 7606 Multiplexor

The 7606 accomplishes all data switching necessary to store data in core storage. Data channels and the central processing unit transmit all data to and from core storage through the multiplexor. The 7606 provides the only means of access to core storage. A maximum of eight 7607 Data Channels may be attached to the 7606. Only one 7606 is used with a 7090 system.

IBM 7607 Data Channel

The 7607 contains the control circuits, registers and counters to provide simultaneous and independent transfer of information between input-output units and core storage via the 7606 Multiplexor. At least one 7607 Model 1 must be attached to the 7090 Data Processing System. A maximum of eight data channels may be attached. Each channel contains a 36-bit shift register and a 36 position data register that transfers data to or from core storage via the multiplexor in a 36-bit parallel operation.

IBM 7608 Power Converter

The 7608 is used to convert the incoming power of 60 cycle alternating current to 400 cycle alternating current. This provides well regulated output power to the system.

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