It provides two external DB25 parallel ports.
For those Lisa operating environments that include appropriate drivers, each port can be used for a parallel port printer (eg. the Apple DMP), or a parallel port hard disk (ProFile or equivalent).
The additional parallel ports appear in the "Startup From" menu, so attached hard disks can be bootable (although some operating environments do not boot properly from an expansion card port).
The dual parallel port card was manufactured by Apple Computer.
Two ROM revisions exist, with a minor difference between them. As most operating environments use their own ProFile driver code, the difference appears to be insignificant.
The Macintosh driver numbers for AppleTalk (DRVR FFD6) and the AppleShare client software (DRVR FFD7) are the same as the driver numbers assigned to ProFiles that are connected to some expansion slot ports.
Therefore, for best results in these environments, when using dual parallel cards with ProFiles:
MacWorks Plus II 2.0 and up were designed to boot properly from any parallel port, however some problems may occur when trying to boot MacWorks Plus 1.1h and earlier from an expansion slot parallel port.
Boot from the built-in parallel port and adjust the preferences to identify which expansion slots and ports have ProFiles attached to them.
When installing Xenix, you are offered the choice of configuring the &/usr partition on a second drive. You may use this info to configure additional drives:
Devices and typical mount points are assigned as follows:
Slot 1 lower: pf2 /usr Slot 1 upper: pf3 Slot 2 lower: pf4 /u Slot 2 upper: pf5 /vExample, to connected a 5 MB ProFile to the lower port of a Dual Parallel Card in slot 2
mkdev pf4 mount /dev/pf4 /u mkfs -y /dev/pf4 9728 1 64 mkdir /u/lost+found