7-3. General description of the parallel interface
The 8255 is used for the LSI to control the parallel inter- face. The 8255 can be set in the following mode.
/PORT A: MODE 0
IPORTB: MODE 1
C:Output
74.Data transfer timing
BUSY
ACK
( 8255 A
v
DATA
STROBE
( M 1 N ) l^s(MIN)
Because it is not possible to directly it uses interrupt for key processing ACK signal is latched by means of
sense the ACK signal as and RS232C input, the the OBF pin function
PRINTER: MZ-1P02, MZ-1P03 CE-
330P, 331P, 332P
*Broken line in the above figure represents timing for the
'For detail of timing, refer to Manual provided with printer.
Set the 20 second counter.
STROBE OUT
Set the 20 second counter.
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