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Macintosh Portable ExpressModem?

Aektann

Well-known member
I’ve got a working Macintosh Portable with the strange modem card installed. The part number is 670-4267-A, Designed by Apple Computers in 1989. It has a standard RS-422 port outside. Looks like an early version of Apple ExpressModem. I tried to search by the part number with no success. Just curious what kind of modem it could be.
 

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cheesestraws

Well-known member
Interesting! Can you post a picture face-on so we can see what all the chips are? No idea what that is doing off the top of my head.
 

LaPorta

Well-known member
Interesting that there is a serial jack there instead of a telephone jack. Could this be a different type of card all together?
 

MOS8_030

Well-known member
Looks like it could be this. Even though the PN is different. Or a version of it.
 

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Aektann

Well-known member
Interesting that there is a serial jack there instead of a telephone jack. Could this be a different type of card all together?
It looks like the the internal ExpressModem card from PowerBook 100 series. There is an additional localtalk-like port to which connects the external modem dongle. Never thought Apple had one for Portable those times.
 

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Aektann

Well-known member
Looks like it could be this. Even though the PN is different. Or a version of it.
Yes, it definitely must be the international modem card. My Portable originally was bought in Netherlands, so it be.
 

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Aektann

Well-known member
Well, I have a standard Apple ExpressModem DAA from PowerBook 180. The port is same yet I’m not sure about the compatibility with the Portable modem card. Could someone please provide a pinout?
 

Aektann

Well-known member
Table 4-15 Signals on the DAA connector
Pin Signalname Direction Pin Signalname Direction
1 GND —
3 MDM_TX_P O
5 MDM_TX_N O
7 GND —
9 MDM_DAA[1]/ O H_UKNUM
11 MDM_DAA[3]/ O H_OHRC
13 MDM_DAA[5]/ O H_AWSMCLK
2 GND — 4 MDM_RX_P I 6 MDM_RX_N I 8 GND —
10 MDM_DAA[0]/ O H_AWSMDAT
12 MDM_DAA[2]/ I L_RINGREADY
14 MDM_DAA[4]/ I L_PHONE
15 GND —
17 n.c. —
19 MAIN_5V —
Signal directions are defined from the main logic board side of the connector; I = input and O = output.

I found this pinout for the relatively modern PowerBook ExpressModem II DAA.
 

Aektann

Well-known member
Well, I'm stuck here. There's no pinout available for DAA port either for ExpressModem or for Int'l Portable 2400 modem. Could someone please help to determine if it is possible to use the actual ExpressModem DAA dongle on the 2400 portable modem port? I don't have any idea about the compatibility of DAA dongles either.
 

DracheMitch

Well-known member
American phone systems actually supply a lot of power when the phone rings (it had to power a motor that rings a real bell, originally), and trickle power to create the dial tone. International systems use that external adapter because their power supply for ring and tone are different. I had a PowerBook Duo that used it. At that point, I’m not sure why Apple bothered making an internal card. The adapter was about the same size as a GV serial modem.
 

Aektann

Well-known member
American phone systems actually supply a lot of power when the phone rings (it had to power a motor that rings a real bell, originally), and trickle power to create the dial tone. International systems use that external adapter because their power supply for ring and tone are different. I had a PowerBook Duo that used it. At that point, I’m not sure why Apple bothered making an internal card. The adapter was about the same size as a GV serial modem.
Yep, I've got this point right. Basically, I'm trying to find the answer here: is it possible to use a relatively modern DAA dongle from PowerBook 100-series ExpressModem for the Macintosh Portable 2400 Int'l Modem as is.
 
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