Octek BISON II, Руководство пользователя

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TECHNICAL INFORMATION
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Channel 2 Tone Generation of
Speaker
Gate 2 Controlled by bit 0 of
port hex 61 PPI bit
Clk in 2 1.190 Mhz OSC
Clk out 2 Used to drive the
speaker
Note : Channel 1 is programmed to generate a 15-micro-second
period signal.
The 8254 Timer/Counters are treated by
system programs as an arrangement of four
programmable external I/O ports. Three are treated
as counters and the fourth is a control register for
mode programming.