IBM 7090 Instruction-Reference page 51

Store Decrement
STD +0622 (I, E)
Figure 5.3-2
The contents of AC(3-17) replace the contents of positions (3-17) of core storage lo-
cation X. The remaining storage positions are unchanged, and the AC is unchanged.
This instruction operates similarly to store prefix, except that MF store decrement
rather than MF store prefix is made active.
Store Tag STT +0625 (I, E) Figure 5.3-2
The contents of AC(18-20) replace the contents of positions (18-20) of core storage
location X. The AC and the remaining positions of core storage are unchanged. This
instruction operates similarly to store prefix, except that MF store tag rather than
MF store prefix is made active.
Store Address
ST A +0621 (I,
E)
Figure 5.3-2
The contents of AC(21-35) replace the contents of positions (21-35) of core storage
location X. The remaining positions of storage and the contents of the AC are un-
changed. This instruction also operates Similarly to store prefix, except that MF store
address rather than MF store prefix is made active.
Store Left Half MQ SLQ -0620 (1, E)
Figure 5.3-3
The contents of positions (S-17) of the MQ replace the contents of positions (S-17) of
storage location X. The remaining storage positions and the contents of the MQ are
unchanged. MF store prefix, MF store decrement, and MF store control lines are
activated so SB(S-17) can be read into storage. The word is sent from the MQ to the
SR so it can be put on the SB.
Store Instruction Location Counter STL -0625
(1, E) Figure 5.3-4
The contents of the program counter, which contains the location of the STL instruc-
tion plus one, replace the contents of positions (21-35) of storage location X. The
contents of the PC and the remaining positions of storage are unchanged. The MF store
address and MF store control lines are activated so the address portion of the storage
word can be changed. The PC contents are sent to core storage on the SB. The con-
tents of the PC are sent to the SR through the AS and the output of the SR feeds the SB.
Load MQ
LDQ +0560 (1, E) Figure 5.3-5
The contents of the MQ are replaced by the contents of stor age location X. The
storage word is put into the SR, and the output of the SR is sent to the MQ.
Exchange AC and MQ XCA +0131
(1)
Figure 5.3-6
The contents of the AC(S, 1-35) are interchanged with the contents of the MQ(S,1-35).
AC positions Q and P are reset. The SR is used for temporary storage while routing the
MQ to the AC.
Exchange Logical Accumulator and MQ
XC L -0130 (I) Figure 5.3-7
This instruction interchanges the contents of AC(P-35) and the contents of the MQ
(S-35). Positions (S) and (Q) of the AC are cleared. Execution is identical to that of
XCA except for the handling of AC positions (S) and (P). The contents of the MQ are
put into the SR. The contents of the SR(S, 1-35) and the AC (P, 1-35) are interchanged,
putting the original MQ in the AC. Gating the output of the SR(S, 1-35) to the MQ(S, 1-35)
places the original AC contents in the MQ. AC positions (Q) and
(S)
are cleared because
of normal shift cell operations.
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