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Computermuseum der Fakultät Informatik				german

Robotron BC5120

general view
Type:          BC-5120                                 <<<    >>>    ^^^
Manufacturer:  VEB Robotron
Technology :   uP U880  (Z80)
Year:          1984

The predecessor of the PC1715 is the PC5120. It is also populated with
the U880. It even owns two processors. There it is not a real double-
processor system but the two CPUs are connected in parallel. There is 
always only one active. On an incoming interrupt, the second CPU is 
used, what makes possible a very short reaction time, because the CPU
registers don't have to be saved. Another feature is the memory 
protection: The CPU can protect single 64-Bit areas against 
overwriting. Also an access from a user to the I/O ports can be caught.

The BC5120 isn't already built on one circuit board like the PC1715, 
but the CPU board, the memory board, the video board and the interface
board are plugged into a backplane. However, for example the MFS-
connector of the PC1715 is very similar to one of the BC5120, if it's 
about the type and the arrangement of the used microcircuits.

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