Jag's World Header




Mad With Macintosh


Controlling Mac OS X With A Mac Plus (or other Classic Mac)


updated 5/4/01 


Allowing telnet access to your computer opens a security hole and allows your computer to be hacked into. If you have protection such as a firewall or other protection, please investigate and see if your security can be breached. If you are using a modem to telnet only for a few minutes, the chance of getting hacked into is much lower, HOWEVER, the risk remains. A much better way to log in remotely is via SSH which is intalled automatically under Mac OS X 10.0.1.



Remember the old days when your Unix computer was just a 'dumb terminal' that 'talked' to the REAL computer? You had no hard drive, just an old fashioned screen with really big keys that were really hard to push down? We're going to do the same thing here. Except the screens are newer, they have hard drives attached and the keys are much easier on the fingers.

If you're too young to remember those days, here's an explanation: You know how you have to log in to your internet provider? You'll be doing the same thing only you'll be logging in to a computer instead of an internet provider. You can log in from the same room, the next building or around the globe.

Setting up a serial link.

If you're setting up your terminal to talk to a Mac running OS X, just use a regular Mac printer cable from printer port of Mac #1 to printer port of Mac #2. If you are using a USB Mac to run OS X, you'll need a Mac serial to USB converter.

If both Macs are on an ethernet network, you're already set.


ZTerm is a complete, easy to use comm program. It's recently been carbonized for Mac OS X compatibiltiy (the Carbon version is not needed for this tutorial). This program can dial a modem or you can connect the two Macs by putting a printer cable between the two as indicated above. This will preclude the need to dial a modem, you'll have a automatic connection between the two Macs.

Telnet is a handy app that allows a telnet connection (d'uh!) to your Macs. It doesn't dial out, so you can only use this app to talk to your other Macs if you are on a network or you have connected to the internet via ethernet or a modem.

NOTE: you don't have to be connected to the internet to telnet into another Mac UNLESS that Mac is outside your LAN (local area netowork.) For instance, if you wanted to connect to a Mac that was on your LAN, you could use ethernet (no dialing needed). If you wanted to connect to a Mac that was outside your LAN, you could use ethernet (a T1, ISDN or ADSL connection for example) or you could use a modem to dial into the internet.

The Setup

 First go to Mac OS X System Preferences. Choose 'sharing'. Click the lock in the lower left corner to allow changes. You might need to type in an administrator usename and password. If you don't know what that is, just type in your username and password and it will work if you are the adminstrator (owner) of this Mac.

Click on the checkbox next to "Allow Remote Access". Close the System Preferences window.

If you've installed the Mac OS X 10.0.1 upgrade, and you want to Telnet into your Mac OS X box, you'll need to turn telnet access back on. See below for SSH access info.


open the terminal,

su to root by typing

su hit enter

type your root password


cd /etc


 pico inetd.conf

locate #shell, #login, #telnet.

remove the '#' from them.

type control x, hit enter.

restart your Mac


Logging in.

 First, launch 'System Preferences' on the OS X Mac. Choose 'Sharing'. At the bottom of the screen it tells you what that Mac's IP address is. This is the number we'll be using to log into your OS X Mac from the other Mac.


If your cables are correctly attached, you're ready to log in. Fire up ZTerm on your classic Mac.

The settings should be as follows:

Data Rate: 38400 (you may need to increase this, your mileage may vary)
Parity: None
Data Bits: 8
Stop Bits: 1

Select the printer port under modem preferences. Keep all the other preferences at their default settings.

You should see a login prompt in the ZTerm window. If not, choose the 'reset terminal' command under the Misc menu or restart ZTerm.

SSH access with NiftyTelnet:

Launch NiftyTelnet 1.1 ssh (this one works on an 020 Mac running system 7 up to and including dual processor G4's running os 9.1). There are other varieties of telnet apps available, some may not work on older Macs. This one allows ssh (secure shell) connections which eliminates the security hole that Telnet opens.

Choose 'New Connection' from the File menu of NiftyTelnet. Click the "New" button. Type in the IP address from above in the 'host name' window. DO NOT lick connect yet. Click on the 'edit' button and under 'Protocol', select SSH - 3DES. You can name this connection anything you want in the 'shortcut name' field. Now click the OK button and then the connect button. You should get a login prompt. Log in as a user and type in the password and you're accessing your OS X Mac from your classic Mac. You can perform all the tasks that your user is allowed to perform.


Communicating with Mac OS X

Now you can control the OS X Mac from your classic Mac. If you logged in as root (not recommended unless you know what you are doing), you can even shut down or reboot your OS X Mac from your classic Mac. You can also create new users, remove files, create files and directories, etc as long as you are logged in as root.

If you're a Unix newbie, here are some simple tutorials.

©1996-04 JagWerks Media