--- title: HEATHKIT H8 categories: - Computers types: - Professional Computer origins: - U.S.A. years: - '1977' cpus: - Intel 8080 A params: name: H8 image: /media/museum/photos/heathkit_h8_1.jpg company: /companies/heathkit company_name: HEATHKIT specs: - label: NAME value: H8 - label: MANUFACTURER value: Heathkit - label: TYPE value: Professional Computer - label: ORIGIN value: U.S.A. - label: YEAR value: September 1977 - label: END OF PRODUCTION value: Unknown - label: BUILT IN LANGUAGE value: Octal editor - label: KEYBOARD value: 16--key Octal - label: CPU value: Intel 8080 A - label: SPEED value: 2.048 MHz - label: RAM value: 256 bytes (upgradable with memory boards) - label: ROM value: 1 KB in basic version - label: TEXT MODES value: N/A - Small display on the front panel displays the registers content. - label: SOUND value: Built-in speaker - label: SIZE / WEIGHT value: Unknown - label: I/O PORTS value: Serial IO (H8-4) and Cassette Interface (H8-5) - label: BUILT IN MEDIA value: Optional ECP-3801 Cassette Recorder / Player - label: OS value: HDOS, CP/M with extended system - label: POWER SUPPLY value: Built-in power supply unit - label: PRICE value: From $499 tabs: - photos - adverts - hardware - emulators - links - docs forum_thread: 146 photos: - title: COMPLETE SYSTEM subtitle: '' text: Complete system with H9 terminal and paper tape reader / punch expansion image: /media/museum/photos/heathkit_h8_complete-system_2.jpg - title: 'COMPLETE SYSTEM #2' subtitle: '' text: Here is a Heathkit H8 computer with a terminal and a floppy-drive. image: /media/museum/photos/heathkit_h8_2.jpg - title: INSIDE subtitle: '' text: We can see here the different boards of the computer. The second board from bottom is a 64k RAM expansion board. image: /media/museum/photos/heathkit_h8_inside.jpg adverts: - title: FRENCH ADVERT (1979) subtitle: '' text: '' image: /media/museum/pubs/heathkit_h8_pub_2.jpg - title: U.S. ADVERT (1980) subtitle: '' text: At the time of this advert (September 1980), Heathkit introduced a music synthetiser board, a speech lab, a color graphic board, a color monitor and Microsoft BASIC and FORTRAN languages. image: /media/museum/pubs/heathkit_h8_pub_1.jpg hardware: - title: H9 TERMINAL subtitle: '' text: This was the first and official terminal for the H8 computer. It is nicely shaped. image: /media/museum/hardware/heathkit_h9_2.jpg - title: H17 DISK DRIVE UNIT subtitle: '' text: The H17 Disk Drive and HDOS (Heath Disk Operating System) were released in late 1978. The unit featured one or two hard sectored 5.25" 102.4 KB disk drives, and was delivered with a disk controller card for the H8. image: /media/museum/hardware/heathkit_h8_h17fdunit_1.jpg - title: 8'' DISK-DRIVES subtitle: '' text: '' image: /media/museum/hardware/heathkit_h8_diskdrives_1.jpg - title: PAPER TAPE READER / PUNCH subtitle: '' text: |- This mass storage peripheral was the ancestor of the tape recorder. It used paper tapes and had independant punch and reader mechanisms allowing tape duplication. It red up to 50 characters per second and punched up to 10 characters per second. Price: $350 in kit form. image: /media/museum/hardware/heathkit_h8_puncher_1.jpg emulators: - title: Virtual H8 Project url: http://davidwallace2000.home.comcast.net/h8/The_Heathkit_H8_Digital_Computer.htm platform: Windows text: Nice designed emulator - title: Project 8080 url: http://davidwallace2000.home.comcast.net/h8/project8080_archive/heath8080a_intro.htm platform: Apple text: A H8 emulator for the Mac links: - title: Daves Old Computers - Heathkit H8 url: http://parse.com/~ddunfield/museum/h8/index.htm text: Interesting page with nice pictures and many docs to download - title: 'Techno-Paleontology : Compusaurus Heathkitus' url: http://davidwallace2000.home.comcast.net/ text: Infos, technical data and home of the Virtual H8 Project. docs: - title: HEATHKIT H8 - OPERATION MANUAL url: http://www.classiccmp.org/dunfield/heath/index.htm cover: /media/museum/docs/couvs/heathkit_h8_operation-manual.jpg text: |- [**HEATHKIT H8 - OPERATION MANUAL**](http://www.classiccmp.org/dunfield/heath/index.htm)written by Heath Company  compiled/archived by Dave Dunfield\  type of document : PDF\  source : [Daves Old Computers](http://www.classiccmp.org/dunfield/heath/index.htm) - title: HEATHKIT H8 - ASSEMBLY MANUAL url: http://www.classiccmp.org/dunfield/heath/index.htm cover: /media/museum/docs/couvs/heathkit_h8_assembly-manual.jpg text: |- [**HEATHKIT H8 - ASSEMBLY MANUAL**](http://www.classiccmp.org/dunfield/heath/index.htm)written by Heath Company  compiled/archived by Dave Dunfield\  type of document : PDF\  source : [Daves Old Computers](http://www.classiccmp.org/dunfield/heath/index.htm) - title: HEATHKIT H8 - 4K STATIC MEMORY BOARD url: http://www.classiccmp.org/dunfield/heath/index.htm cover: /media/museum/docs/couvs/heathkit_h8_4k-static-memory-board.jpg text: |- [**HEATHKIT H8 - 4K STATIC MEMORY BOARD**](http://www.classiccmp.org/dunfield/heath/index.htm)written by Heath Company  compiled/archived by Dave Dunfield\  type of document : PDF\  source : [Daves Old Computers](http://www.classiccmp.org/dunfield/heath/index.htm) - title: HEATHKIT H8 - SERIAL I/O AND CASSETTE INTERFACE CARD url: http://www.classiccmp.org/dunfield/heath/index.htm cover: /media/museum/docs/couvs/heathkit_h8_serial-and-cassette-interface.jpg text: |- [**HEATHKIT H8 - SERIAL I/O AND CASSETTE INTERFACE CARD**](http://www.classiccmp.org/dunfield/heath/index.htm)written by Heath Company  compiled/archived by Dave Dunfield\  type of document : PDF\  source : [Daves Old Computers](http://www.classiccmp.org/dunfield/heath/index.htm) oc_id: 134 source: url: https://web.archive.org/web/20230323144800/http://www.old-computers.com/museum/computer.asp?c=134 date: '2023-03-23' --- This early computer was to be used with a terminal for better control. A lots of expansion boards were available for this computer. Memory boards were available in 4K, 8K, and 16K (note: 4k memory board was 8k half populated.) The H8 was sold with software: Benton Harbor BASIC, the HASL-8 2 pass assembler, TED-8 Line oriented text editor and BUG-8 terminal console debugger. --- Further information from **John H. Swalby**:\ Built, used, developed on H8 from 77-84. no longer have any hardware, manuals, etc. just some old photos.\ **1)** the keypad is Octal, as is the display. in fact, the 8080 is basically an octal oriented machine. the instructions are mostly based on 3 bit source and destination fields. Heathkit's early software offerings were all octal. HASL & Bug-8. they used a peculiar bastardized version called "split octal" where each word is represented by 2 octal bytes. so address range looked like 000 000 to 377 377 (0x0000 to 0xFFFF) as opposed to 000000 to 177777.\ **2)** As the product matured, Heath offered a CPU replacement card based on the Z80. This ran CP/M instead of HDOS. Also most of Gates' early stuff, ASM-80, BASIC-80, FORTRAN-80, etc, also UCSD-Pascal p-system was offered.\ **3)** Chassis had large unregulated power supply. Up to 2 regulators were mounted on an aluminium bracket on each card to spread out the heat dissipation. There was no motherboard per se. There was an 88 pin 'backplane' along the right side of the box. The cards were mounted at an angle roughly parallel to the front panel. This was to optimise convection cooling. There were NO FANS. There was a small speaker to beep and add key-clicks for the keypad.\ **4)** Add on cards included: 2-port serial I/O for terminal and casette recorder interface; 4-port serial I/O; H17 floppy disk interface; 2-channel D/A card with 4 part music synthesis software; parallel interface card (possibly for high speed (300baud) papertape reader/punch).\ **5)** The H17 floppy drive was a separate box connected by a ribbon cable. It supported up to 2 - 5.25" full height Wangco drives. Disks were 10 sector - hard sectored floppies. This means there were 11 index holes around the hub. 1 for start of track, and one for each sector! These were VERY expensive. $65.00cdn for a box of 5. Under HDOS they held 104K, under CP/M 80K, formatted. Usually O/S, editor, compilers, utilities were on the first disk; while sources, objects, lists, and user executables were kept on the second. **Jacques Trepanier** remembers:\ My father bought one in june of 1976 and we were members of the HUG (Heathkit User Group) in Montreal, Canada in 1977.\ We ran Benton Harbor basic (from heathkit) and I programmed the 8080 directly using the 16 key keypad. We had an audio tape cassette and a H9 monitor converted to display 24 X 80 caracters (originally it was 12 X 80.\ The computer built in language was not hexadecimal, it was split octal.\ Also, the computer came with 256 bytes of RAM. You had to buy memory boards, either 4k or 8k. The 4k board was a half populated 8k board. In 76-77 a 8k RAM board was worth $1000 canadian in Montreal.\ The H8 had a built-in speaker and it biped when you turned it on. Some people developped music programs in machine language and you had to modify the speager circuitery to play music. It was an RC (Resistor Capacitor) filter if I remember correctly . Our computer play New York new York and The Sting among other popular songs. We copied that music from US magazines.