Technical Details.
PC IEEE Reference
C1
Controller Function.
System Controller.
C2
Controller Function.
Send IFC and Take Charge.
C3
Controller Function.
Send REN.
C4
Controller Function.
Respond to SRQ.
C9
Controller Function.
Send Interface Messages.
Parallel Poll.
Pass Control.
Receive Control.
Take Control Synchronously.
E1
Open Collector Driver.
250 kilobytes per second maximum speed.
The functions supported by the PC IEEE board are a
comprehensive group allowing full control of the IEEE bus. The
PC IEEE has complete controller capabilities and also
implements the full range of talker, listener, serial and parallel
poll, service request, and remote programming functions.
In/Out Structure.
_______________
The computer controls the state of the IEEE lines through
an Motorola MC68B21 PIA chip, this does not connect directly
to the IEEE lines but is buffered through two IEEE line drivers
that provide the correct signal levels and line matching. The line
drivers used are the Texas Instruments SN75160 and SN75161
IEEE driver chips. These control the IEEE data and IEEE line
management respectively. The operation of these devices is NOT
trivial and should only be attempted by competent personnel who
are in possession of the device data books. These books are :-
"8-Bit Microprocessors Data Manual" from Motorola
Semiconductors and "The Texas Instruments Interface Circuits
Data Book." Briefly, you must set BOTH the PIA and the line
drivers to the appropriate input or output state, then set the
required lines either HIGH or LOW. Then perform the
appropriate IEEE handshake by setting the management lines
high and low at the correct time.
Alternatively handshake the data or commands out of or in to
the computer using the jump table. The jump table, accessed via
the device driver, does provide complete control of all possible
IEEE functions. The SN75160 and SN75161 line drivers are
Chapter 3
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