The DS3800HMPF1E1E is an early version of the triple modular redundant controller module designed by General Electric for their Mark IV Speedtronic system. While Speedtronic systems have been used successfully for the management of gas and steam turbine systems since the 1960s, the Mark IV was the first of its kind that offered TMR voting and distributed control.
The DS3800HMPF1E1E is a rectangular board that has been built around an Intel 8086 microprocessor. This chip is a third-generation microcontroller that includes HMOS technology and direct hardware support for programs that were written in a high-level language while supporting full 16-bit processing. The data bus on the 8086 is multiplexed with the address bus to allow control lines to fit within the dual in-line 40 pin package. This chip has four 16-bit segment registers with access to one MB of memory.
In MKIV systems, data from the DS3800HMPF1E1E board will be compared to data coming from the two other controllers before being used for display or control of the system. This allows the Mark IV to offer back up to all decisions through distributed control voting.
The DS3800HMPF1E1E includes factory-made drill holes to allow for mounting. It is built with a backplane on one end, a right-angled connector on the other, and a vertical pin connector in the center of the board. This last connector is used for a ribbon connector that allows the board to communicate with an optional auxiliary board that can be mounted to the surface of the HMPF.