Lesson 7: Addressing Modes
From the original article in Radio-Electronics
by Jonathan A. Titus
The Memory Address/Manual Control
module is used to hold data which is to be
used as the memory address. Two 8-bit
latches are provided since the computer will
use one set of eight bits for a memory address
and the other set of eight bits for control
functions. Since the microprocessor can directly
address up to 16,424 words of memory,
commonly noted as 16K, we will need
14 binary bits for the complete address. The
complete memory address of any location is
given by a 16-bit binary number; X X B
3 B
3
B
3 B
3 B
3 B
3 /
B
2 B
2 B
2 B
2 B
2 B
2 B
2 B
2.
where the X's represent bits that are not
used. The computer specifies any address
by first sending out the B
2 bits to one of the
eight-bit latches, followed by the six B
3 bits
and two X bits. Control of the correct latch
is supplied from the CPU module.
Read More: Mark-8 Construction.pdf, p.2 [2.54 MB]