IBM 1620 1 Manual page 37

Table 2. 1620 Indicators
Machine Code
Name
light
Turned on by Turned off by
1620 01-04 1620 Program Switches 1-4 No Operator (Program switch On) Operator (Program switch Off)
06 Read Check Yes I/O Input Error BI, BNI, or Reset key
07 Write Check Yes I/O Output Error BI, BNI, or Reset key
09 Last Card (1622 Card Read) Yes
Last Card Data Transfer to Core Storage BI, BN I, or Reset key
11
High-Positive (H/P) Yes
Arithmetic Resu It positive and greater than zero Reset key or next arithmetic instruction
12 Equal-Zero (E/Z) Yes Arithmetic Result of zero Reset key, or next arithmetic instruction
13 H/P or E/Z No Indicator 11 or 12 Indicators 11 and 12 Off
14
Arithmetic Check Yes Arithmetic Check BI, BNI, or Reset key
15 Exponent Check
Yes Exponent Overflow/Underflow BI, BNI, or Reset key
16 MBR-E Check
Yes Parity Error in MBR-E BI, BNI, or Reset key
17 MBR-O Check Yes Parity mor in MBR-O
BI, BNI, or Reset key
19 Any Check No Indicator 06, 07, 16, 17, or 39 On
Indicators 06, 07, 16, 17, and 39 Off
1311
36 Address Check Yes Unequal address, or no address found in BI, BNI, or Reset key, or disk operation
disk storage or multiple heads or multiple
drives are se lected
37 Wrong-Length Record/ Yes Incorrect record length, or corresponding
BI, BNI, or Reset key, ~r disk operation
Read-Back Check data in disk storage and core storage does
not compare
38 Cylinder Overflow Yes Disk operation completes last sector and BI, BNI, or Reset key, or disk operation
sector count is not 000
39 Any Disk Error No Indicator 36, 37, or 38 On
Indicators 36, 37, and 38 Off
1443 25 Printer Check
Yes Parity error or sync. check in 1443 If a parity error: BI, BNI, 1620 or 1443 Reset
keys.
If a sync. check error: 1443 Reset key only.
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Channel 9 No Punched hole in Channel 9 of carriage BI, BNI, 1620 Reset key, or a punched hole in
control tape Channell of carriage control tape.
34 Channel 12 No Punched hole in Channel 12 of carriage BI, BNI, 1620 Reset key, or a punched hole in
control tape Channell of carriage control tape.
35 Printer Busy No 1443 printing (buffer is unavailable for 1443 Completion of printing (buffer avai lable
loading) for loading}
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Seek Complete No End of Seek Operation BI, BNI, or Power-on Reset
Branch No Indicator (BNI-47)
Their associated indicators (16 and 17) are turned on
if a parity error occurs.
Any Check (19). This indicator provides the means
of interrogating five error conditions ( Indictors 6, 7,
16, 17, and 39) with a single Branch Indicator or
Branch No Indicator instruction-no indicators are
turned off by the instruction. Indicator 19 is turned off
only when all of the five error conditions are off.
Description. Same as Branch Indicator (BI-46)
except that the branch occurs when the indicator is
off.
Disk Storage Indicators
(36-39). These indicators are
used in conjunction with the
IBM
1311 Disk Storage
Drive. They are described briefly under 1620
CONSOLE
and described in more detail in the publication IBM
1311 Disk Storage Drive (Form A26-5650).
Execution Time. If branch occurs (indicator on),
T
==
200 JJ-sec. If the branch does not occur, T
==
160
JJ-sec.
Execution Time. If the branch occurs (indicator
off), T
==
200 t-tsec. If the branch does not occur,
T
==
160 t-tsec.
Branch No Group Mark (BNG-55)
Description. This instruction is available when the
1311 Disk Storage Drive is attached to the System.
The purpose of this instruction is to enable the pro-
gram to test for the presence or absence of a group
mark in core storage.
If the core sto:rage location specified by the Q
address does not contain a group mark, the program
branches to the instruction at the P address. (The
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