Index Registers; Storage Register; Service Aids; One Card Programs - IBM 7090 Instruction-Reference

7.1. 09 Index Registers (Systems 02.07.01. 1-02.07.15.1)
The index registers are three identical 15-position registers using shift cells. When
the registers are read out, the information comes out in complement form (Figure
7.1-6). Lines controlling the index register are:
ADD to XR
Gate XRA to ADD
Gate XRB to ADD
Gate XRC to ADD
Set XR
Hold XR
02.12.70.1
02.12.26.1
02.12.26.1
02.12.26.1
{
02.12. 72.1 and
02.12.73.1
7.1.10 Storage Register (Systems 02.01. 00. 1-02. 01. 37.1)
The storage register is a 36-position register of shift cells. The storage register
has eight inputs with the following controlling lines (Figure 7. 1-7).
ACC to SR
02.12.03.1
ADD to SR 02.12.05.1
MQ to SR 02.12.08.1
OP Keys to SR 02.12.09.1
SR to SR 02.12.10.1
IND to SR
02.12.13.1
Address Switch to SR 03.06.12.1
SB to SR 02.12.50.1
Set SRR 02.05.00.1
Hold SR 02.05.00.1
7.2.00 SERVICE AIDS
7.2.01 One Card Programs
Programs other than the normal diagnostic programs may be used to troubleshoot
the machine. For instance, in diagnosing troubles which appear only when the cus-
tomer's program is being run, the program may be altered slightly to isolate the
trouble. Then, if the program is one used regularly, it becomes a good diagnostic in its
altered form. In cases of this kind, pass along the information to allow newly released
diagnostic programs to incorporate it.
Short programs that you write yourself are also handy when working on a machine.
Punch these programs on cards and save the time used to enter them in storage with
the keys. Make each card self-loading, if possible, and there will be less cards to
keep track of. Keep a file of these one-card programs and add to it. A few samples
of one-card programs are given below.
Display Storage
This program causes display of the contents of sequential storage locations, starting
with the location entered in the operator's panel keys. The card is self-loading and
halts on its first pass to allow the operator's panel keys to be set. After the start key
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