The HP-48S/SX series of calculators not only came with a "large" 64 x
131 pixel display, it also included a serial port. Using the cable and
the right software, you could connect it to your PC / Mac and transfer
data to and from it.

This is the Mac software needed to transfer files between your HP 48
calculator and your Macintosh. In addition, there's other useful
applications included:

 * KERMIT: The protocol for transferring files between a Macintosh
   computer and an HP 48. (Kermit must be running on the computer
   before you can transfer files.)
 * GROBer: A Macintosh application that converts an HP 48 graphics
   object into a Clipboard picture, and vice versa.
 * APPT: An appointment calendar program for the calculator.
 * USAG: A calculator program that enables you to see the usage for
   any HP 48 command.
 * CLK: A calculator program that adjusts the calculator's system
   clock to keep it accurate.
 * INPRT: A calculator program that enables the HP 48 to receive
   infrared output from other HP calculators.
 * STPWATCH.LIB: An HP 48 library containing a stopwatch application
   for the calculator.
 * PCLPRINT.LIB: An HP 48 library that enables you to print a
   graphics object on a PCL printer, such as the HP DeskJet printer.
 * EPSPRINT.LIB: An HP 48 library that enables you to print a
   graphics object on an Epson printer, such as the FX-85 printer.
 * HP-48 Font: A Macintosh font file that invokes the Font Mover
   application and provides an HP 48 font.

DL#1 version 1.0, consisting of a Disk Copy 4.2 image of the floppy

Compatibility
Architecture: 68k