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1400 Provisional Feed Latch
1400 Compat Timeout
1400 Comp Read Feed
Rd r Rely and Comd Valid
AO
1400 Comp Read Feed
'-=.;.;:;.....;;.:;..c""--.
AO
1---"
Rdr Command Gate
Bus Out 0
Bus Out 1
Bus Out 3
1400 Comp Rdr Busy
Bus Out 6
Not Rdr Adapter Reset
AO
Not Rdr Device End Smp
Not Rdr Adapter Reset
AO
10
1400 Comp Rdr Feed Command
Not Rdr Queued On
Not Rdr Feed Command
1400 Campat Prov Feed
AO
1400 Comp Rd Pch Bus in
Rdr Command Gate
Reoder Sense
Not 1400 Compat Timeout
Not Rdr Adapter Reset
AO
Status in Sample
Figure 5-13.
Card Read
The micro program for stacker select
can detect whether or not the
6-millisecond timeout is over by issuing
a sense command prior to the feed and
stacker select command.
If the status
byte coming back from the channel does
not contain the attention bit, the
6-millisecond stacker select time has
expired (Figure
5-13).
In this case;
the micro program does not issue the
stacker select command, but will
indicate an invalid stacker select to
the operator by a coded byte in the
R-register.
Another modification of the 1402
circuitry on the 2030 changes the end-
of-file condition.
When the 1402 is
operating in 2030 mode, an extra Read
command must be issued after the last
card is read in order for the end-of-
file file condition to occur.
In
compatibility mode on the 2030, end-of-
file occurs with channel end of the. last
card read.
This allows the branch on
last card to occur without issuing an
extra read command.
5-22
1402 Punch Operation
A stacker select command given by a 2030
to the 1402 punch causes the card about
to be punched to be selected.
A stacker
select command given to the 1402 punch
on the 1401 or 1460 systems causes the
card at the punch check station to be
selected.
To make the stacker select
command on the 2030 system apply to the
card at the punch check station while
operating in compatibility mode, the
punch 3-bit modifier latch has been
added to the control circuitry_
The
punch 3-bit modifier latch turns on when
a 3 bit is on the bus with a punch
command.
When the punch 3-bit modifier latch
is on, it prevents the punch stacker
sequence 1 latch from turning on and
causes the punch stacker sequence
2
latch to come on at punch counter F-E
tim.e.
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