Lesson 10: Interfacing and Interrupts
From the original article in Radio-Electronics
by Jonathan A. Titus
The Mark-8 Minicomputer may be used
with the TV-Typewriter to display computer
generated information. The interface
uses either the A or B Output Port
strapped to the specific output code, 1-7,
that you select. The A and B output ports
have strobe lines which are pulsed during
the output cycle. These two lines are
found above the B output lines and below
the A output lines on the printed circuit
board. These strobe lines provide us with
the Keypressed signal required to enter
data into the TV Typewriter. A monostable
is attached to this strobe line to stretch
the pulse width and the 10 mF capacitor
used for debouncing IS removed from the
TV-Typewriter.
Read More: Mark-8 Construction.pdf, p.5 [2.54 MB]
The INTERRUPT is used to do just that to the computer.
We can interrupt the present program and cause the computer to
temporarily do some other task and then return to the program . It
is also possible to make the computer leave a stopped state with the
interrupt.
Read More: Mark-8 Construction.pdf, p.7 [2.54 MB]