Apple Macintosh System 7.5 - Manual (Page 21)

Step 5: Choose a printer
If you’re upgrading from System 6 or an earlier version, you must reselect
your printer before you can print with the new system software.
m Use the Chooser to select a printer.
Using your upgraded Macintosh or PowerBook before you complete
the group upgrade
If you want to use your upgraded Macintosh or PowerBook on the network
before you’ve completed the group upgrade, be aware of these conditions:
m If you print from the upgraded computer to a LaserWriter used by System
6 computers whose printer software hasn’t been upgraded, the printer will
restart itself. It will restart again each time it switches from one printer
driver version to the other. This is remedied when you perform the group
upgrade.
m If your computer is using EtherTalk on an AppleTalk Phase 1 network,
installing System 7.5 will upgrade your EtherTalk driver to Phase 2. You
will be unable to use any network services until you upgrade your network
to AppleTalk Phase 2. (See “EtherTalk Networks” in “Planning the Group
Upgrade.”)
17 Upgrading Your Own Macintosh or PowerBook