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Vikram Aggarwal

Connect an old Apple to the world

How to connect an old dead machine to a screaming 100Mbps line, and watch it work!

You have old Apple junk? You have Linux?

So I got myself a screach owl, a Duo that Apple made about the time I was getting out of High School. I used to marvel at the machines since they were so cool, and so small, but could never afford one.

Me too!

Finally, I was able to get one dirt cheap at my University's surplus auction. I already have a flashy new iBook (700Mhz, CD writer, the works) but it was fun working on an old machine, to relive the past.

The only problem was that the old machine was so dead, it could not even connect to the Internet. The big problem with the Duos is that they have just a serial port and a modem. I tried for quite some time, but could not get the modem to work. That was really painful. So I thought I would just sell the machine and get it out of my hands. But the lure of the cool machine kept pulling me back.

Can we get it to work?

So I thought I would find some way to connect it through the serial port or the Duo Dock. The dock was a really bad idea, since the dock that I bought with the machine was worth less than I paid for it (which was a song, anyway), so I just opened it up, looked inside, and threw away the casing. I kept the motherboard and the other parts, and tried working with them, but nothing came of that, so they are lying in my closet now. (They will be thrown shortly).

Then I came across a web-page which showed how an enterprising person had connected his old Apple to a PC and got zmodem to work to transfer files. I looked through the Duo hard-disk and could not find a file transfer utility. But since it had a modem, I conjectured that it could do PPP. Like a French Queen once said, "If they don't have bread, why don't they eat cake?"

Let's start!

The things you require are:

  1. Old apple computer with a working serial port.
  2. Any Intel computer with Linux on it (Yeah, baby!)
  3. Cable
  4. Macintosh Serial connector (male)
  5. PC Serial connector (female)
  6. A willingness to run wild!

So parts 3-5 are used to build a null modem cable. The circuit diagram and instructions are given here. Luckily, a friend of mine let me rummage through his immense cable collection, and found me a Mac-PC serial null modem cable. May God bless his soul. For this, I am immensely thankful to Dana Lutton.

Thanks, thanks! :)

Build the cable, and test it with a multimeter, or a battery and a lamp that works with the lamp. (You know how to do this, right? )

Linux configuration

Now, on the Linux machine (where all the work happens), you start pppd. The concept is that Linux acts like an ISP for the teeny Mac machine. The Mac believes that it is calling Compuserve (or whichever ISP you remember) and uses the Internet.

The Linux machine runs the command:
pppd -d -detach /dev/ttyS0 57600

Where ttyS0 is where the null modem cable is plugged in. You need my options.ttyS0 file for this. This goes in /etc/ppp, or wherever you find the ppp options file. A good way to find out is that there is an options.ttyXX file in that location. In this file, you can see is the IP of the Linux PC, and is the IP of the Apple machine. Change to suit the local flavor.

Apple configuration

On the Apple machine (where you toil the most), you will have to do a couple of things:

  1. Enable all MacOS extensions, except the ones that could use your serial port. Specifically ask the printers to take a hike (disable their extensions), and AppleTalk should be politely asked to take some other port. Disabling AppleTalk is not sufficient as I found out. Even though it was disabled, it was laying claim over the serial port. I was almost about to give up, and give the Duo to my friend. So, follow my example. Tell AppleTalk to give up the port in question. Disable all fax software, disable printers. Make sure nobody wants your serial port which has the null modem cable plugged in.
  2. Now, tell the modem control panel that your modem is null modem 57600, and point it to the port where you have put the null modem cable.
  3. For checking, you might want to run getty on the Linux machine, and start the ppp connection from the macintosh. You start getty on the tty, like this: /sbin/getty -L ttyS0 57600 vt100
  4. If all is fine, the Mac should give you a terminal (you enabled it in the PPP options, didn't you?) and let you login the Linux machine. If you are here, chances are that things are going to work! Play around the Linux machine, since you are logged in. See how painful it is to have small bandwidth (10Mbps is not small, BTW)
  5. Now, stop the getty, and start the ppp process. Additionally, you should start ipchains (or iptables with kernel 2.4.x) to make the Linux machine act as a gateway for the Apple computer. My ipchains script is provided here for reference.
  6. With any luck, you should be connected. Fire up some browser and go to Google. Verify that life is good, as it should be.

Now you can download all the old apple software you can get your hands on, and fool around with it. Remember to send me an email saying how much you loved this page, and how it helped you to discover your inner self.

Last minute update

Unfortunately, Shufflepuck Cafe corrupted my Apple's hard-disk, and I cannot boot from the Duo anymore. (It shows the infamous blinking question mark. Let it be known that Apple made good hardware, but lousy software.) I'll wait either for someone to show me how to kick start this into action, or just throw it away. In any case, I have learnt something from this machine, and don't mind it's death so much. In any case, if there's something to be learnt, it is that a machine without a floppy or CD drive is quite a pain. Live and learn...

You can reach me at "aragorn at infofin dot com". This page was last updated on: Thu Oct 13 09:39:14 PDT 2005