IBM 709

The improvements included overlapped input/output, indirect addressing, and three "convert" instructions which provided support for decimal arithmetic, leading zero suppression, and several other operations.They are conditional jump operations based on the values in the decrement registers specified in the tag field.The primary improvements of the 709 over the previous 704 involved more magnetic-core memory and apparently the first use of independent I/O channels.Up to two IBM 733 Magnetic Drum units, each with 8,192 words of memory, could be attached independently from the Data Synchronizers.Although the core array drivers all used vacuum tubes, the read sense amplifiers were a very early use of transistors in computing.
IBM 709 front panel at the Computer History Museum
Computer History MuseumcomputerIBM 704indirect addressingdecimal36-bitmagnetic-core memoryemulatorFORTRAN Assembly Programvacuum tubesIBM 7090index registerslogical orsign/magnitude formatfloating-pointIBM 729IBM 716IBM 711Magnetic DrumIBM 738List of vacuum tube computersIBM 740SHARE Operating SystemSQUOZEBell Telephone LaboratoriesJohn Wiley & Sons, Inc.305 RAMACAN/FSQ-7AN/FSQ-8