Radio Shack Quick Printer II Reference Handbook

Peripheral Read Strobe: IN * operates somewhat
like RD*; except IN* is a port function. When
I
N* goes low, the CPU is looking for data on
the address bus that comes from the port
specified by the 8 lower order bits of the
address bus (A0 thru A7l. The Z80 will
address
up to 256 input ports.
Interrupt Input: INT*, when taken low, will
force
the CPU to a predetermined address in
ROM. There are three modes of operation. In
the first, this line is ignored. In the second
mode, INT* causes the CPU to go to address
0038 Hex and to go on from there. In the last
mode, the CPU may go anywhere in memory
you want but this function cannot be used in
the TRS-80 due to internal circuits. See a
Z-80 technical manual for more information
on this input.
Interrupt Acknowledge: INTAK* goes low
whenever
the CPU enters an interrupt mode.
It is useful for external circuitry to know that
the CPU actually did go into an interrupt
routine.
System Ground: Ground is the reference point
of all voltages and logic levels in the T RS-80.
5
Volt Output: This line comes from the 5-volt
power supply. The power supply in the
TRS-80 is designed to drive just the TRS-80
and a little more for overhead. It is suggested
that you do not use this output for external
devices.
In Level II machines this pin has been
modified to show a ground, instead of 5 volts.
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Radio Shack Quick Printer II Specifications

General

Brand	Radio Shack
Model	Quick Printer II
Category	Desktop
Language	English