CompuPro - CPU 86/87
This was CompuPro's main 8086 CPU board.
While the CPU 85-88 allowed easier transition from 8 to 16 bit software it was
slower than this fully dedicated 16 bit processor.
The CPU 86/87 was one of the most
advanced 16 bit processors available for the IEEE 696/S-100 Bus. Based on
Intel's high performance 8086 16 bit processor, it also included sockets for the
8087 high speed math co-processor and the 80130 Operating System Firmware
component. Via a special arrangement with Intel, CompuPro supplied this board
with a "ROM-less" version of the 80130 so that the user may retain full use of
that part's interrupt and timer capabilities without paying for software that
probably would not use. The CPU 86/87 however was designed to accept the
ROM part should it be needed. The CPU 86/87 included circuitry that allowed it
to handle 8 and 16 bit memory and I/O devices that conformed to the IEEE
696/S-100 protocol for 8 and 16 bit transfers. Both 8 and 16 bit types could be
mixed in a system, the CPU 86/87 dynamically adjusted itself to the proper bus
width. The CPU 86/87 was fully compatible with DMA devices that adhere to the
IEEE 696/S-100 standard protocols (like CompuPro's DISK 1A, DISK 2, DISK3 etc.).
The CPU 86/87 operated at 8 and 10 MHz
clock speeds, but was designed to accommodate faster clocks as faster CPUs as
they were introduced. A special clock switching circuit allowed the use of
specially designed slave processors to share the bus with the CPU 86/87. Use of
an 8 bit slave CPU provided the equivalent operation of their CPU 8085/88 dual
processor board, thus providing a simple way to execute libraries of existing 8
bit software, as well as CompuPro's exclusive MP/M 8-16. The CPU 86/87 included
power-on-jump capabilities that allow it to begin program execution on any 4K
boundary in the lower 1 megabyte of address space. When you couple high speed
operation with the power of the 8086/8087 pair, the CPU 86/87 was truly a
processor board for the advanced computing systems of the early eighties. BTW,
the seldom used front panel connector was finally gone.
The manual for this board can be
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