The Hewlett-Packard 9830A is a desktop-sized, all-in-one computer, released in 1972. It was usable out-of-the-box, booting to BASIC (stored in ROM) immediately at power-up. It incorporates a 16-bit processor, full alpha-numeric keyboard, 32-character alpha-numeric LED display, and digital cassette tape drive, in one package, with ROM firmware and I/O expansion capabilities. Read-write memory is up to 8KW (16KB). The tape cassettes can hold on the order of 35KW (70KB) each.

The 9830 was something of a closed system, to my knowledge there was no complete service manual or schematic released by HP in 'normal' publications, nor was there machine language or assembly programming documentation or support. It was intended to be used and programmed in BASIC, and that's all.

HP did file a substantial patent (UK#1,444,141, US#4012725) however, that covers the 9830 in considerable depth, if one can stand wading through the hundreds of pages of diagrams, listings and patent-ese language with no table-of-contents or index. The UK patent is better organised than the US version, and far preferable for perusal. A version of the UK patent and a rudimentary-and-partial table of contents for the same are linked below.

These pages focus on technical aspects of the HP 9830. For some history of the development of the 9830 see the great articles at hp9825.com. Working in conjuncton with Rob Ferguson, these pages present:

• Hardware Architecture Description: An accessible technical description and overview of the 9830 hardware, including a complete schematic. The material has been compiled from a reverse-engineering of a 9830A unit, with some reference to the patent HP filed for the 9830.
• Machine Architecture Description: Similarly, documentation for the processor at the machine-instruction level.
• Machine-Language Programming: Techniques for creating machine-language programs for the 9830, and downloading those programs into the 9830.
• Tape File Server: Techniques for using a modern host as a 'tape server' to a 9830. This is accomplished with the use of the MPSI I/O Interface.
• Tape Imaging: Techniques for reading and writing byte-for-byte images of physical 9830 cassette tapes to/from a modern host. This can be accomplished two ways:
  • using the internal 9830 tape drive with the MPSI I/O Interface,
  • using a 9865 tape drive with an I/O adapter.
• Print Capture: A method of displaying and capturing print output from the 9830 on a modern host. This can be accomplished two ways:
  • using the MPSI I/O Interface,
  • using the 9866 Printer Mimic I/O adapter.
• Downloading Source: A method to download BASIC source into the 9830 from a modern host. This can be accomplished with the use of the MPSI I/O Interface.

SOME PERIOD CONTEXT

PROCESSOR SPEED

Instruction execution times vary for different instructions, but to give an idea of the processor speed, the timing for a typical instruction has been calculated. It turns out the basic add-memory-to-register (ADA/B) instruction takes 13.25uS, an execution rate of 75,000 instructions per second. See the hardware architecture page for more detail.

TECHNICAL: Machine Architecture Hardware Architecture Microcode Listing ALU ROM Functional Listing Memory Cycle Sequences SCHEMATICS: HP 9830A Computer (PDF) HP 9865 Tape Drive (PDF) HP 9866 Printer (PDF) MPSI (PDF) 9865 Adapter (PDF) 9866 Mimic (PDF)

PROJECTS: The MPSI I/O Interface The Machine Binary-Block Machine-Language Programming HP 9865 Tape Drive & I/O Adapter 9866 Printer Mimic Support Programs Source (pgm9830.tgz)

MISCELLANEOUS: Photo Gallery Table-of-Contents for UK Patent #1,444,141 Unit Log

RELATED: HP 2116 series EXTERNAL LINKS: Rob Ferguson's 9830 story 9830 assembler and disassembler, and UK Patent #1,444,141, at Rob Ferguson's site History of the 9830 at hp9825.com The 9830 at the HP Computer Museum The Wang 2200