IBM 7090 Instruction-Reference page 138

Storage table required for CRQ (in decimal):
Storage Contents
Location ( S-5) ( 21-35)
2000
BL
2000
2001 1 2010
2002 2 2010
2003 3 2010
2004 4 2010
2005 5 2010
2006 6 2010
2007
7
2010
2008 8 2010
2009 9 2010
Development of Program
LDQ A
CRQ 2000, 0, 6
Series of Steps within CRQ
1st
Char
Conv
Sl-5
*0
Storage Contents
Location (S-5) (21-35)
2010
0 2010
2011 1 2010
2012 2 2010
2013
3
2010
2014
4 2010
2015 5 2010
2016
6
2010
2017 7 2010
2018 8 2010
2019
9 2010
CONTENTS OF MQ
6-11 12-17 -23 -35
MQ
Shift
Left 6
Table Next
Count
C(MQ)s Start Table
C(-)s Starting Loc
1-5 Loc Refer 1-5
C(-) 21-35
*0 + 2000
=
2000 BL 2000
0 9
BL
5
0
+
2000
=
2000
BL 2000
7
+
2000
=
2007
7
2010
1
+ 2010
=
2011 1
2010
0
+
2010
=
2010
0
9
+
2010
=
2019
9
9 ";'BL}..BL
4
BL:;"BL¥ 7
3
B~7~1
2
7~lyO 1
1 0 9
0
Count
=
0; if Tag
=
1,
XRA
The execution of CRQ is accomplished in one L cycle and a number of E cycles equal
to the count.
Convert by Addition from MQ CAQ -0114(Min I, L) Figure 5.3-73
(Max I, L, 6E)
This instruction treats the MQ as six 6-bit representations, as does CRQ. This
instruction does not replace any of these representations, but uses them to locate a
number of storage words equal to the count of the instruction. The storage words are
located at the address developed by adding MQ(S-5) to SR(21-35) (initially the instruc-
tion address) and are brought to the SR. The storage words are then added to the
contents of the accumulator. The MQ is not replaced, but is merely rotated left six
places to allow the next six-bit representation to be added to the address portion of the
previous storage word. The process continues until a number of additions (to the AC)
equal to the count have been made. The operation is then complete. The address por-
tion of the last storage word used can be stored in index registers for future reference
by adding a tag bit in position 20 of the instruction.
137