We had those
in every PC in the office.
Made PCs suddenly useful ;-)
Can I ask what you were doing that needed more than
two serial ports?
Especially "every PC in the office".
A modem,
serial mouse,
serial printer,
serial "RS232" scanner, external drive (yes, they existed), serial control
of CD cchanger (consider Kubik 240 disc carousel (SCSI, but serial disc
change control)), serial EPROM programmer, serial drawing tablet, serial
X10 controller, serial VOTRAX, logging of UPS, etc.