HP 85 ASCII ART

AN HP-85 COMPUTER, HP 7970E TAPE DRIVE AND

HP 2631G PRINTER COLLABORATION

HP 85 ASCII ART DEMO

In this demo, a trio of old HP machines collaborate to print ASCII art the vintage way.

HP-85 info on this page.

HP 7970 info on this page.

Info on interfacing the HP 7970 to the HP 85 on this page.

HP 2631G info on this page (TBD).

Technical Documentation

I needed to create quite a bit of stuff to make this working:

  1. HP-85 program to interface with the tape: HP-85 program to read from HP 7970 Tape

  2. Hardware for generating HP-IB parity on the fly: FPGA HP-IB Parity Generator

  3. ASCII art files: ASCII Art Text Files

  4. Program to generate the SIMH tape from ASCII pictures: bin2simh

  5. Resulting SIMH tape file: ascii2.tap

  6. DOS utility to write to a SCSI 9-track tape (written by John Wilson): DOS "ST" SCSI Tape Drive Utility

  7. DOS utility to read from a SCSI 9-track tape (written by Chuck Guzis): DOS "STP2TAP" SCSI Tape Drive Utility

Procedure and software to write the physical tape

Unfortunately you can't write to the HP 7970 tape drive from the HP 85. That's because the 85 cannot keep up with providing data fast enough to the tape, and you'll get a timing error. So instead, the physical magnetic tape used in this demo was written using another SCSI tape drive, my HP 88780B (also known as the HP 7980), as shown in this video (reproduced below).

I used a DOS machine with a SCSI card to connect to the HP 88780, and ran the DOS "ST" utility written by John Wilson . The command to used to write the above SIMH .tap file to the physical tape was (my tape SCSI address was 5):

st -f scsi5: iput ascii2.tap

Similarly, to read the file back, use

sst -f scsi5: iget dump.tap

Or you can use Chuck Guzis' STP2TAP utility above, which can read back, but not write. In this case the command is:

stp2tap dump.tap

Video of the HP 8870 Tape used to write the physical tape for the demo

Video of the repair of the HP 2631G used in this demo

File Archive

ASCII art files and generated SIMH tape file used in the demo:

Utility to create the .tap file above in SIMH format from the ASCII art text files

DOS "ST" 9-track SCSI tape utility by John Wilson

DOS "STP2TAP" 9-track SCSI tape utility by Chuck Guzis