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AMIGA
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AMICUS
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AMICUS05.ADF
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parallel
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1986-01-15
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Parallel Interface Connector Specification
--------------------------------------------------
The 25 pin D type connector with pins (DB25P=male) at the rear of
the Amiga is nominally used to interface to parallel printers. In
this capacity, data flows from the Amiga to the printer. This
interface may also be used for input or bidirectional data
transfers. The implementation is similar to Centronics, but the pin
assignment and drive characteristics vary significantly from that
specification (see Pin Assignment). Signal names correspond to
those used in the appendices of the hardware manual when possible.
Parallel Connector Pin Assignment (J8)
--------------------------------------------------
pin name dir notes
-------------------------
1 DRDY* O Output data ready signal to parallel device in
output mode, used in conjunction with ACK*
(pin 10) for a 2 line asynchronous handshake.
Functions as input data accepted from Amiga in
input mode (similar to ACK* in output mode).
See timing diagrams in following section.
2 D0 I/O =
3 D1 I/O =
4 D2 I/O = D0-D7 comprise an 8-bit bidirectional
5 D3 I/O = bus for communication with parallel
6 D4 I/O = devices, nominally a printer.
7 D5 I/O =
8 D6 I/O =
9 D7 I/O =
10 ACK* I Output data acknowledge from parallel device in
output mode, used in conjunction with DRDY*
(pin 1) for a 2 line asynchronous handshake.
Functions as input data ready from parallel
device in input mode (similar to DRDY* in
output mode). See timing diagrams in following
section. The 8520 can be programmed to
conditionally generate a level 2 interrupt to
the 68000 whenever the ACK* input goes active.
11 BUSY I/O This is a general purpose I/O pin shorted to a
serial data I/O pin (serial clock on pin 12).
Note: Nominally used to indicate printer
buffer full.
12 POUT I/O This is a general purpose I/O pin shorted to a
serial clock I/O pin (serial data on pin 11).
Note: Nominally used to indicate printer paper
out.
13 SEL I/O This is a general purpose I/O pin. Note: nominally
a select output from the parallel device to the
Amiga.
14 GND
15 GND
16 GND
17 GND
18 GND
19 GND
20 GND
21 GND
22 GND
23 +5V 100 ma maximum. *** WARNING +5V. ***
24 ---
25 RESET* O Amiga system reset
Parallel Connector Interface Timing, Output Cycle
PA<7:0>___ _________________________________________ __
PB<7:0>___X_________________________________________X__
|<-- T1 --->| |
| |<-------- T2 ------>|
_______________V V________________________
DRDY* |________|
output data ready |<- T3 ->|
|<--- T4 --->|
____________________________|<- T5 -->|__________
ACK* |_________|
output data acknowledge
microseconds
min typ max
T1: 4.3 -x- 5.3 Output Data setup to ready delay
T2: nsp -x- upc Output Data hold time.
T3: nsp 1.4 nsp Output Data Ready width
T4: 0 -x- upc Ready to acknowledge delay
T5: nsp -x- upc Acknowledge width
nsp = not specified
upc = under program control
Parallel Connector Interface Timing, Input Cycle
PA<7:0>___ _________________________________________ __
PB<7:0>___X_________________________________________X__
|<-- T1 --->|
| T2 -->|<----->|
_______________V ____________|__________
ACK* |________| |
input data ready |<- T3 ->| |
|<-- T4 --->|
___________________________|<- T5 -->|__________
DRDY* |_________|
input data acknowledge
microseconds
min typ max
T1: 0 -x- upc Input data setup time.
T2: nsp -x- upc Input data hold time.
T3: nsp -x- upc Input data ready width
T4: upc -x- upc Input data ready to data acknowledge delay
T5: nsp 1.4 nsp Input data acknowledge width
nsp = not specified
upc = under program control