1980s Vintage Computers

Hewlett-Packard Series 80 - HP-87


The HP-87 was the follow-on model to the HP-85 in the 'Series 80'. It was a logical development, keeping the same processor and clock speed, but with the following changes:

  • Basic language extended ie long variable names added, support for larger graphical display, total 48K in ROM.
  • Allows programs to address memory above 64K, through use of an extended memory controller.
  • HP-87 has 32K RAM built in, and allows up to 4 extra RAM modules of either 32K, 64K or 128K ie 534K max.
  • Built in HP-IB interface, together with software support for basic I/O, mass-storage and printing without additional ROMs.
  • Bigger screen allowing 80 column text, with either 16 or 25 lines.
  • No built in tape or printer.
  • Support for multiple (up to 5) binary programs in RAM.

The HP-87 was followed by the HP-86 and HP-87XM. The HP-86 lost the internal monitor in favour of an external monitor, and lost the built in HP-IB connector in favour of a Centronics parallel printer port and two connectors for HP floppy disks. The HP-86 also had 64K RAM whilst the HP-87XM included 128K RAM. There is an excellent article on the HP-86 and HP-87XM architecture in the December 1982 edition of the HP Journal. The final machine in the series 80 family was the HP-86B, which went back to having a built-in HP-IB port and featured 128K of RAM. 

I have an HP-87, together with the following ROMs:

  • Advanced Programming 1 & 2.
  • Plotter ROM.
  • Input/Output ROM.
  • Assembler ROM.
  • Extended Mass Storage (with its own Easter Egg).

I have EPROM versions of the following ROMs:


The EMS ROM allows the use of an HP 9122D dual 3.5" floppy drive, as this uses the SS-80 protocol rather than the earlier Amigo protocol.

I also have the following which can be used on either the HP-85 and HP-87:

  • 82901M dual 5.25" floppy drive
  • 9121 dual 3.5" drive
  • Two 128K RAM modules (for use on HP-85B as RAM disk)
  • Programmable ROM module
  • System Monitor module
  • HP-IB interface module
  • Serial interface module
  • Speech Synthesis module

For documentation I have the HP-87 owners manual, and the 'Introduction to the HP-86' which outlines some of the differences between the HP-85 and HP-86 & 87.

Olivier de Smet has produced an excellent HP-85 and HP-87emulator

I would very much like to contact anyone with any software or program listings, so please e-mail me.

HP Series 80 tips

Picture courtesy of Computissimo

This page was last revised on: 12/04/09