Node:Storing operators, Next:Arithmetic operators, Previous:Loading operators, Up:MIX instruction set
The following instructions are the inverse of the load operations: they are used to store a subfield of a register into a memory location. Here, MOD represents the subfield of the memory cell that is to be overwritten with bytes from a register. These bytes are taken beginning by the rightmost side of the register.
STA
V <- rA
.
STX
V <- rX
.
STi
V <- rIi
.
STJ
V <- rJ
.
STZ
V <- 0
.
By way of example, consider the instruction STA 1200(2:3)
. It
causes the MIX to fetch bytes no. 4 and 5 of register A and copy them to
bytes 2 and 3 of memory cell no. 1200 (remember that, for these
instructions, MOD specifies a subfield of the memory
address). The other bytes of the memory cell retain their
values. Thus, if prior to the instruction execution we have
[1200] = - 20 21 22 23 24 [rA] = + 01 02 03 04 05
we will end up with
[1200] = - 20 04 05 23 24 [rA] = + 01 02 03 04 05
As a second example, ST2 1000(0)
will set the sign of
[1000]
to that of [rI2]
.