


Macintosh RS-422
It's possible to connect RS-232 peripheral to the RS-422 port
available on Macintosh computers. Use RXD- as RXD, TXD- as TXD,
Ground RXD+, Leave TXD+ unconnected, GPi as CD.
(At the
computer)
8 PIN MINI-DIN FEMALE at the computer.
| Pin |
Name |
Dir |
Description |
| 1 |
HSKo |
 |
Output Handshake |
| 2 |
HSKi/CLK |
 |
Input Handshake or External Clock |
| 3 |
TXD- |
 |
Transmit Data (-) |
| 4 |
GND |
 |
Ground |
| 5 |
RXD- |
 |
Receive Data (-) |
| 6 |
TXD+ |
 |
Transmit Data (+) |
| 7 |
GPi |
 |
General Purpose Input |
| 8 |
RXD+ |
 |
Receive Data (+) |
Note: Direction is DTE (Computer) relative DCE (Modem).
Note: GPi is connected to SCC Data Carrier Detect (or to
Receive/Transmit Clock if the VIA1 SYNC signal is high). Not
connected on the Macintosh Plus, Classic, Classic II, LC, LC
II or IIsi.
Contributor: Joakim Ögren, Pierre Olivier, Ben Harris, Nathan Schmidt
Sources: comp.sys.mac.comm FAQ Part 1
Sources: Apple Tech Info Library, Article ID:
TECHINFO-0001699
Please send any comments to Joakim Ögren.