Vector 4 - Page 112

EXHIBIT 1I-23 PARALLEL PROTOCOL (“QUME TYPE")
The "Qume Type" protocol uses parallel addressing through the programmable 8255
PPI Chip.
8255
8255
8255
8255
CONTROL SEQUENCE
GBI
PORT 09H
CONTROL SIGNALS
........
T
-
Electronic
Controls
]
PRINTER
Electronic
Controls
.......
.......
PRINTER
A
PORT 0AH
DATA
.“.. .6 ¢ .:'0. '.o .‘" :.: K ¢
3:
:..'E.".
:.:
:.:E.:j:o::
...
PORT 08H
CONTROL CODES
PORT 09H
PORT 0AH
(PIN 39)
Electronic
Controls
PRINTER
Electronic
Controls
PRINTER
......
......
......
PAPER
Printer is initialized:
Carriage, vertical spacing
and other controls are
set.
Printer control signals are
checked.
Data and specific control
codes (hammer intensity,
etc.) are sent to printer.
Printer begins printing.
Printer sends control
signal out pin 389.
II5-21