Centronics 101AL Technical Manual page 204

Data Input Causing Busy
The diagram in Figure C-2 shows the interface timing involved in
transferring any data which causes a busy condition in the printer.
_jo.5 us 0.5uS
"{(MIN) } (MIN)
0.5 wS (MIN)
4 ee uS (MAX)
BUSY WZ. LL
ACK
—]| BUSY DELAY BUSY > DELAY
ACKNOWLEDGE : r
DATA
DATA STROBE
101/101A/101S* 101AL 102A 102AL 301 306 500 501
BUSY DELAY 0 0-1.5 usec ) 0-1.5 usec 0-1.5 usec 0-1.5 usec 0-1.5 usec 0-1.5 usec
ACK DELAY 0 0-10.0 usec 0 0-10.0 usec 0-10.0 usec 0-10.0 usec 0-10.0 usec 0-10.0 usec
ACK 4 usec 2.5-5.0 usec 4 usec 2.5-5.0 usec 2.5-5.0 usec 2.5-5.0 usec 2.5-5.0 usec 2.5-5.0 usec
BUSY
Line Feed 75-105 msec 75-105 msec 75-105 msec 16 msec (single| 70-100 msec 75-105 msec 75-105 msec 70-100 msec
75.105 msec
Form Feed (1ll-inches) 3-3.5 sec 3-3.5 sec 3-3.5 sec 3-3.5 sec 1.5-2.0 sec 3-3.5 sec 3-3.5 sec 1.5-2.0 sec
Delete 3 msec 100-400 usec 3 msec 100-400 usec 100-400 usec 100-400 usec 100-400 usec 100-400 usec
Bell 2 sec 0 2 sec 0 0 0 0 0
Select 3 msec 100-400 usec** 3 msec 100-400 usec** 100-400 usec** 100-400 usec**! 100-400 usec** 100-400 usec**
Deselect Until printer |Until printer Until printer| Until printer {Until printer Until printer Until printer Until printer
is selected is selected is selected is selected is selected is selected is selected is selected
Print Command 6 msec/char 6 msec/char 470-500 msec 410-415 msec 6 msec/char 8.4 msec/char 8.4 msec/char 6 msec/char
plus 75-105 plus 75-105 (total) (total) plus 70-100 plus 75-105 plus 75-105 plus 70-100
msec LF msec LF msec LF msec LF msec LF msec LF
(Return time-no busy) (240 msec max) (240 msec max) (0) (0) (270 msec max) (270 msec max) (400 msec max)| (400 msec max)
*Vertical Tab and Form Feed durations for the 101S apply to 6 line/inch operation.
**No busy if inhibit prime on select option is used.
Figure C-2. BUSY CONDITION TIMING
Rev. C C-2