DX10 Data Channel

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The DX10 Data Channel was an adapter which could interface between OEM-produced peripherals, and a PDP-10, using the PDP-10's PDP-10 Memory Bus and PDP-10 I/O Bus. (So, it could be connected to KA10s and KI10s, but only to KL10s with the optional old-style Memory and I/O busses (provided by the DMA20 Memory Bus Adapter and DIA20 IBus Adapter‎, respectively.) The DX10 can also use an MX10 Memory Multiplexer.

The original intended configuration was with a TX01 Magnetic Tape Controller, along with one or more (up to eight, maximum) TU70 or TU71 magnetic tape drives; the ensemble was designated a 'TU70 Magnetic Tape Subsystem' (or 'TU71' as appropriate).

The 'channel bus' between the DX10 and the TX01 is an IBM I/O channel bus.


The DX10 is built around a PDP-8/A microprocessor; the PDP-8/A uses an OMNIBUS to talk to its sub-systems, and is enhanced with off-board logic to implement a number of IOT instruction operations specific to the TU70 Magnetic Tape Subsystem application. The PDP-8's code is held in a normal PDP-8 4K RAM, the 'control storage memory', and was loaded into the DX10 by the host CPU after power-on. (The host PDP-10 can start and stop the PDP-8, and read and write its internal memory, and DX10 internal registers.) There is also an Internal Bus (IBUS) used to communicate between the sub-systems in the DX10.

The DX10 was composed of seven major sub-systems:

  • PDP-8 and its sub-systems
  • Memory Bus Register and Control
  • Channel Command Register
  • Data Channel
  • I/O Bus interface
  • Data Channel Interface
  • Channel Bus Interface

These are held mostly on seven hex boards, and two quad boards:

  • M8315 PDP-8/A CPU
  • M8311 PDP-8 4KW RAM (quad)
  • M8317 PDP-8 ROM Bootstrap Loader
  • 2 x M8595 Memory Bus Interface
  • M8596 Channel Bus Interface (quad)
  • M8597 PDP-8/A Interface
  • M8598 I/O and Memory Control
  • M8599 Byte Assembly Logic

and a number of single-width bus interface cards:

  • 4 x M564 I/O Bus Receiver
  • 4 x M664 I/O Bus Driver

They plugged into a pair of system unit-sized backplanes (a 4-slot and a 9-slot), mounted in a separate cabinet (an H950) along with the power supply.

See also

External links