| Apple IIc Serial Port | Imagewriter | Apple Modem |
| DTR (1) | 6 - DSR | 6 - DTR |
| TXD (2) | 3 - RCD | 9 - TXD |
| GND (3 | 7 - GND | 3 - GND |
| RCD (4) | 2 - TXD | 5 - RCD |
| DSR (5) | 20 - DTR | 2 - DSR |
_ ___ l ]
l_l \\ l ]
(5) (1) \\ ________ / ]
)________) ]
(4) (2) / \\ ]
(3)___/ l ]
l_]
DIN type connector DB type connector |
Setting up the printer port from within a program on the IIc is essentially the same as changing the settings on previous interface cards: after first directing output to the serial port (using PR#1 and PR#2 for Ports 1 and 2, respectively), the commands can then be sent to the serial port. Each command for Port 1 must be preceded by CTRL-I. The commands for Port 1 are:
Cmd -- Description
nnn -- Set line width( from 001 through 255): This command must be followed by an 'N' or a <CR>.
nnB -- Set baud rate to value corresponding to nn.
nn -- Rate
01 -- 50
02 -- 75
03 -- 110
04 -- 135
05 -- 150
06 -- 300
07 -- 600
08 -- 1200
09 -- 1800
10 -- 2400
11 -- 3600
12 -- 4800
13 -- 7200
14 -- 9600
15 -- 19200
nB -- Set Data Format to values corresponding to n.
n -- Format
0 -- 8 data 1 stop
1 -- 7 data 1 stop
2 -- 6 data 1 stop
3 -- 5 data 1 stop
4 -- 8 data 2 stop
5 -- 7 data 2 stop
6 -- 6 data 2 stop
7 -- 5 data 2 stop
I -- Echo output to screen.
K -- Disable <LF> after <CR>.
L -- Generate <LF> after <CR>.
nP -- Set Parity corresponding to n.
n -- Parity
0 -- none
1 -- odd
2 -- none
3 -- even
4 -- none
5 -- mark (1)
6 -- none
7 -- space (0)
R -- Reset Port 1 and exit from serial port 1 firmware.
S -- Send a 233 millisecond Break character
Z -- Zap (ignore) further command characters (until CTRL-Reset or PR#1). Do not format output or insert carriage returns into output stream.
Differences between ports:
Listed below are the differences between commands for Port 1 and Port 2 of the Apple IIc.
Port 2 uses the same commands, with the differences and additions listed below. Each command for Port 2 must be preceded by a CTRL-A.
nnn -- same
nnB -- same
nD -- same
I -- same
K -- same
L -- same
nP -- same
Q -- Quit Terminal Mode
R -- same
S -- same
T -- Enter Terminal Mode. Use this command after IN#2 only. If you follow this command by PR#2, the IIc will echo input to output. (NOTE: If the other device is also echoing input to output, entering the first character will cause an infinite loop. Use CTRL-RESET to get out.
Z -- same
CTRL-T -- When issued from a remote device, this command puts the IIc in terminal mode if IN#2 is already in effect. The command is the same as CTRL-T typed locally.
CTRL-R -- When issued from a remote device, this command undoes the terminal mode command. If IN#2 and PR#2 are in effect, the remote keyboard and display become the input and output devices of the local IIc. The command is the same as CTRL-A Q typed locally.