IBM 1132

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Image:IBM logo.svg The IBM 1132 Line Printer was part of the IBM 1130 Computer. It printed 120 character lines at 80 lines per minute. The character set consisted of numbers, upper-case letters and some special characters.

The 1132 was built around a stripped down IBM 407 printing mechanism. The 407 was IBM's top-of-the-line accounting machine from the 1950s. The 1130 had 120 power transistors, each wired to the hammer solenoid at a 407 print position. As the print drum spun, the 1130 received an interrupt for each character position. The print driver software had to output a 120 bit vector designating which transistors were to fire for that cycle. This put a big burden on the software, but resulted in an inexpensive (for the time) printer.

Sometimes a printer output line transistor would fail, resulting in a blank print position. If you knew your way around inside the 1130, it was possible to swap circuit cards so as to move the bad print position to near the right end of the printed line. This kept the 1130 usable until the repair person showed up.

The 1132 came in two models with the following characteristics:

• Efficient typewheel printing concept.
• Standard 48-character-set typewheels include FORTRAN special character set.
• High-speed online printing.
• Model 1 prints up to 80 alphameric or 110 numeric lines per minute and can be attached to 1131 CPU Models 1, 2, 3, and 5.
• Model 2 prints up to 40 alphameric or 55 numeric lines per minute and may be attached only to the 1131 CPU Model 4.
• Standard 120 print-line positions spaced 10 characters per inch.
• Operator selection of vertical line spacing, 6 or 8 lines per inch.
• Forms skipping under program control through automatic, paper-tape-controlled carriage.
• Printer operation under stored-program control through automatic interrupt system.
• Direct connection to the 1131 Central Processing Unit by means of the 1132 Printer Attachment and an Expansion Adapter.