macintosh serial port connections
hello all:
i would like to use my BS2 connected to my mac for communication
during runtime (i.e. not for programming -- i've read the pdf at the
parallax site, etc. about using virtual pc).
however, i can't seem to find the pin diagram for the mac's serial
port and for diagrams i find that *might* be right, i'm not sure
whether DTR would be connected to ATR or would it be DCD, etc. etc.
so, i'm sure someone must have figured this and i would be ever so
grateful if someone could fill in the blanks for me:
mac mini-din female pin number to basic stamps pin
? sout
? sin
? atn
? gnd
also, on the pc diagram provided by parallax, pins 6 and 7 (DSR and
RTS) are connected. is this necessary for the mac?
thanks so much for any light you can shed on this matter.....
chund
i would like to use my BS2 connected to my mac for communication
during runtime (i.e. not for programming -- i've read the pdf at the
parallax site, etc. about using virtual pc).
however, i can't seem to find the pin diagram for the mac's serial
port and for diagrams i find that *might* be right, i'm not sure
whether DTR would be connected to ATR or would it be DCD, etc. etc.
so, i'm sure someone must have figured this and i would be ever so
grateful if someone could fill in the blanks for me:
mac mini-din female pin number to basic stamps pin
? sout
? sin
? atn
? gnd
also, on the pc diagram provided by parallax, pins 6 and 7 (DSR and
RTS) are connected. is this necessary for the mac?
thanks so much for any light you can shed on this matter.....
chund
Comments
However here is some info from (http://csgrad.cs.vt.edu/~tjohnson/pinouts/):
mac serial port:
(printer end)
Connector: mini-circular-square-din-type connector
U
8 7 6
5 4 3
2 1
1 handshake out (DTR?)
2 handshake in (RTS?)
3 TD-
4 GND
5 RD-
6 TD+
7 GPinput (NC on Mac plus and earlier)
8 RD+
This is an RS-422 interface not RS-232, hence the paired IO pins (+ and -).
To connect to an RS-232 device: attach the - pins to the RS-232 data
pins, and RD+ to ground. The handshake in and out are the hardware flow
control, GPinput is carrier detect.
So you'd need a converter.
Here is another pinout from
(http://www.hut.fi/Misc/Electronics/docs/lan/mac_serial.html)
Macintosh (DTE) Modem (DCE)
DIN-8 DB-25
Pin Signal Signal Pin
3 TxD-
TxD 2
4 GND ----+
GND 7
8 RxD+ ----'
5 RxD-
RxD 3
6 TxD+ (nc)
/
###
\ 1 HSKo Output Handshake
/ ### \ (Zilog 8530 DTR pin)
/ \ 2 HSKi/CLK Input Handshake *OR*
/ [noparse][[/noparse]|] [noparse][[/noparse]|] [noparse][[/noparse]|] \ External Clock
/ 8 7 6 \ 3 TxD- Transmit data (-)
| |
| | 4 Ground Signal ground
| === === === |
| 5 4 3 | 5 RxD- Receive data (-)
| |
| | 6 TxD+ Transmit data (+)
\----+ === === +----/
\###| 2 1 |###/ 7 N/C (no connection)
\##| |##/
\| |/ 8 RxD+ Receive data (+)
\
###
/
###
However, I have also heard this:
The serial ports use the EIA422 standard which is a 'differential' system
using 5 volt outputs. It is possible for the Mac to accept 'single ended'
RS232 data (on pin 5) by grounding pin 8 at the Mac end. You can usually
send 5 volt data (from pin 3 on the Mac) to a RS232 input but the noise
immunity will be reduced.
That corresponds with the pinout above.
So to summarize, ground pin 8, RX on pin 5 and transmit on pin 3.
Hope that helps.
Regards,
Al Williams
AWC
* Floating point math for the Stamp, PIC, SX or any microcontroller:
http://www.al-williams.com/awce/pak1.htm
you want.
> i would like to use my BS2 connected to my mac for communication
> during runtime (i.e. not for programming -- i've read the pdf at the
> parallax site, etc. about using virtual pc).
>
> however, i can't seem to find the pin diagram for the mac's serial
> port and for diagrams i find that *might* be right, i'm not sure
> whether DTR would be connected to ATR or would it be DCD, etc. etc.
>
> so, i'm sure someone must have figured this and i would be ever so
> grateful if someone could fill in the blanks for me:
>
> mac mini-din female pin number to basic stamps pin
> ? sout
> ? sin
> ? atn
> ? gnd
>
> Subject:
>
> Disclaimer: I know nothing (and I mean nothing) about the Mac.
>
> This is an RS-422 interface not RS-232, hence the paired IO pins (+
> and -). To connect to an RS-232 device: attach the - pins to the
> RS-232 data pins, and RD+ to ground. The handshake in and out are the
> hardware flow control, GPinput is carrier detect.
>
>
> So you'd need a converter.
>
They use the National DS8925(as does some of the Kodak digital
cameras) which is a TIA/EIA RS422 driver/receiver chip that runs +
and - 5V differental signal. The RX has a range of +8 to -8V