All of the machines and systems shown here are preserved in the depths of the "Computer Garage" and most are in operational condition! (many are used on a regular basis)
All images and video clips herein are Copyright ©
1996,1997,1998,1999 James Willing
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inclusion of the above copyright notice. Any other use is prohibited without
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Baker Diagnostics ROM/RAM Board
This one turns out to be a good reminder, NOT to plug something in just because it appears to be like something you are familiar with!
I took another look at this board recently while working on some machines, and found some things that indicated that this board IS NOT an S-100 board, even though it has the proper connector and form factor!
So... does anyone out there ever recall running across this board, and if so just what does it go into???
California Computer Systems S-100 Terminator board
(details to follow...)
CompuServe 'Node' board
The amazing things you will find from time to time... This card is actually branded with the "CompuServe" logo, and was described to me as a 'node' card. It has what appear to be eight UART chips on it, so I suspect it was part of a communications controller.
CompuServe used DEC equipment for their host systems for a number of years, and this card looks somewhat like a Q-Bus form factor card, but is longer than the norm.
Computalker CT-1 Speech Synthesizer
One of the first (if not the first) serious speech synthesis boards for the S-100 bus. Supplied with extensive documentation, and a modified BASIC language interpreter providing control fucntions for the card, some extremely good (for its time) speech could be produced by this board.
When you considered that the only available alternative at the time was the early (and very expensive) Votrax units, this card was a bargain.
Computalker 'PhoneTalker' Board
I found three of these boards in a system that recently came into the collection. The overall configuration suggests that the system was an interactive voice response system. Sadly, no manuals or software. Does anyone out there have any docs on these boards?
Cromemco Bytesaver
The first of Bytesaver series of EPROM burners. This unit programs the 2708 (1k x 8) EPROM, and could hold up to 8 of them for a total of 8kb of non-volatile storage.
Cromemco Dazzler
(pictures to follow...)
"Affordable color graphics for S-100 computers!" proclaimed the magazine. Following in the tradition of the Altair 8800, the 'Dazzler' two board graphics unit first appeared as a magazine construction article.
The one thing that did surprise some people, was that the unit had no on-board memory. (one of the ways that they kept the price down) Using a new (to microcomputers of the time) technique called 'DMA' (Direct Memory Access) the 'Dazzler' depended on a (relatively) fast 8kb memory board to be in the system that the unit would use for video memory.
The 'Dazzler' quickly became quite popular with hobbiests and was well supported with software and graphics driver utilities from Cromemco, and perhaps just as important a series of games made available on paper tape. (the prevalent medium of the time)
Many a customer was drawn into the local computer store by an Altair or IMSAI sitting in the front window running 'Kaliedoscope' on a 'Dazzler' with a color TV for a display.
Cromemco D+7A I/O board
(pictures details to follow...)
Cromemco Zpu
One of the most popular Z-80 CPU boards for the S-100 bus. This board offered a 2-4mHz switchable CPU clock so as not to disturb timing dependent software/hardware, and functioned equally well in Altair or IMSAI chassis. (before Cromemco came out with a line of their own, originally in an OEM'd IMSAI chassis)
Digital Equipment Corporation 4k Magnetic Core Memory for the PDP-8/i
Details to follow...
Digital Equipment Corporation 8k Magnetic Core Memory for the PDP-8/e/f/m
The three boards shown here make up an 8k by 12 bit magnetic core memory module for the PDP-8/e/f/m computer.
The first board (DEC G233) is the X-Y driver board for the core array. The second (DEC G646) is the actual magnetic core array. The third (DEC G111) is the 'Sense Inhibit' board.
The three boards all connect to the computer through the 'OMNIbus', which is the backplane interconnect bus for the later model PDP-8 series machines. The boards also connect directly to each other through connector across the top of the boards which allow them to finction as a single module.
Although 'core' memory is rarely seen in use today, (at least in contemporary machines) new memory technologies that have similar properties are are in common use. Unlike the DRAM (Dynamic Random Access Memory) chips found in most computers today, magnetic core memory was 'non-volatile'. That is to say that core memory does not 'forget' what is stored in it when the computer power is turned off. The component in common use today that functions most similar to core memory is known as 'FLASH' memory.
Digital Equipment Corporation M837 board
Details to follow...
Digital Equipment Corporation M8330 PDP-8/e/f/mTiming Generator board
This board is the third board that comprises the CPU set in the DEC PDP-8/e/f/m computer. This board provides system timing and syncronization functions.
Digital Equipment Corporation M8655 board
Single port asyncronous terminal interface board
Digital Equipment Corporation M???? OMNIbus board
Details to follow...
Digital Equipment Corporation M???? OMNIbus board
Diode based ROM boot board.
Digital Equipment Corporation M???? OMNIbus board
'Simple' DECtape interface.
Digital Equipment Corporation M???? OMNIbus board
High-speed paper tape reader/punch interface board.
Digital Equipment Corporation M???? OMNIbus board
Details to follow...
Digital Equipment Corporation M???? OMNIbus board
Card reader interface board
Digital Equipment Corporation M???? OMNIbus board
RX8E floppy drive interface board.
Digital Equipment Corporation M???? OMNIbus board
Dual port, 12 bit digital output board.
Digital Equipment Corporation M???? OMNIbus board
Single port, 12 bit digital input board.
Digital Equipment Corporation M???? OMNIbus board
RL01/02 Controller for the PDP-8/a minicomputer.
Digital Equipment Corporation R202 'Flip-Chip' module
The module shown above is an example of how many computers in the 1960s were made. The early DEC PDP-8 line of minicomputers and its peripherals were made up of literally hundreds of modules similar to this.
Known at the time originally as system 'building blocks', each module made up one circuit in the computer. The sheet of paper that the module is shown on is the data sheet for the module, and also shows a schematic if the circuit made up by this module.
DEC DLV-11j 4 port Serial I/O Board
Four serial I/O ports for DEC Q-bus based computers.
DEC TK-50 Cartridge Tape Controller Board
(details to follow...)
DEC TU-58 DECtape II Controller Board
(details to follow...)
DEC VAX 11/750 CPU Board Set
The heart of the mighty '750! (details to follow...)
DEC MicroVAX III CPU and Memory Board Set
The heart of the MicroVAX III! (details to follow...)
Extensys 64k S-100 RAM Board
(details to follow...)
Generic homebrew parallel keyboard
Parallel keyboard for a home computer made from a mainframe data entry terminal keyboard mounted in a homebrew case.
Heatkkit S-100 Floppy Disk Controller Board
(details to follow...)
Heuristics Inc. Speechlab
(pictures details to follow...)
Hewlett Packard 1000F Minicomputer boards
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 |
| 64k HSM (memory) board -- 12747H | F.E.M. (rom) board -- 12791 |
 |
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| Time Base Gen board -- 12539A | Intf board -- 13037 |
 |
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| Grd True In/Out board -- 12566 | Microcircuit board -- 12566 |
 |
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| BACI board -- 12966A | Line Printer board -- 26099A |
 |
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| 7970 MagTape 1 -- 13183 | 7970 MagTape 2 -- 13183 |
 |
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| Standard Memories 256kw board | 256kw memory -- 12749H |
 |
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| I/O Buffer -- 12979 | 8 Channel Multiplexer -- 12792 |
 |
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| ??? -- 91750 | Jumper -- ??? |
 |
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| Disc Int'f 1 -- 13210 | Disc Int'f 2 -- 13210 |
 |
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| Datum HP I/O -- (3rd party) | Disc Inft -- 13183 |
(details to follow...)
IBM PCjr BASIC Language Cartridge
ROM cartridge accessory for the IBM PCjr.
IMSAI 8080 CPU board
The original 2MHz 8080 based CPU board for the IMSAI 8800 microcomputer. Introduced only a matter of months after the premier of the Altair 8080, the board included improvements to the circuitry which made for more stable operation in many cases, most notably the CPU clock circuitry.
IMSAI CR-1 Cassette Interface board
(details to follow...)
IMSAI SIO Dual Channel Serial I/O board
(details to follow...)
IMSAI RAM-4A Memory board
(details to follow...)
IMSAI VIO Video Display board
(details to follow...)
Industrial Micro Systems S-100 8k Static RAM Board
(details to follow...)
Industrial Micro Systems S-100 16k Static RAM board
(details to follow...)
MITS Altair 8080 CPU board
The original 2MHz 8080 based CPU board for the Altair 8800
MITS 88-2SIO serial I/O board
MITS two port asynchronous serial I/O board based on Mororola UART chips. This example has components for one of the two available ports installed.
MITS 88-4PIO parallel I/O board
MITS fairly capable four port parallel I/O board based on Mororola PIC (Peripheral Interface Controller) chips. This example has components for two of the four available ports installed.
MITS 88-ACR Audio Cassette Record Interface board
(pictures to follow...)
A valient (anthough frustrating to a number of early users) attempt to salvage the investment in a earlier modem product (which reportedly failed).
MITS coupled a modem on a board with their original 88-SIO serial card and offered it as a cassette storage interface. The down side of this was that if it did not work as a modem, it probably would not work that much better as a tape interface. (and it didn't)
Later modifications to the unit did finally provide marginally acceptable performance, but by that time competition in the form of the Tarbell Cassette Interface board had arrived and quickly captured the market through mush more reliable operation and widespread software support.
MITS 8800-PMC Eprom Memory Board
(details to follow...)
MITS 88-ROM Memory Board
Also known to some as 'BASIC on a Board'.
Holding 16k of ROM, the only use of this particular board that I am aware of was with a special verions of MITS Extended BASIC which was ROM resident and allowed for (near) instant boot of a diskless machine.
The unit shown has the original BASIC ROMs, and was loaned to Microsoft (along with the Altair 8800 from the collection) for the presentation that Bill Gates did for the Smithsonian Museum for their audio-visual history of the Computer Age. (which I hope to actually see someday)
MITS Altair 256 byte memory board
(pictures to follow...)
The original memory board offered with the Altair 8800. A whole 256 bytes (not k-bytes, just bytes!) of static memory, expandable to 1kb of memory.
MITS Altair 4k byte 'Synchronous' (dynamic) memory board
I guess everyone has at least one product that they wish would just go away... This was one such case. Dynamic memory was still somewhat of a 'black art' at the time, and this board was never really reliable, and was quickly followed up by the 4k static memory board which was much more reliable.
MITS Altair 4k byte static memory board
The much more successful (and stable) follow-up to the 4k synchronous memory board.
MITS Altair Floppy Disk Controller boards
(details to follow...)
Micro Works DS-68 Video Digitizer board
(details to follow...)
Mullen TB-2 S-100 Extender board with Logic Probe
(details to follow...)
NorthStar A4 Floppy Disk Controller Board
(details to follow...)
NorthStar AD3 Floppy Disk Controller Board
(details to follow...)
NorthStar Z-80 Processor Board
(pictures / details to follow...)
Polymorphic Systems Video Interface Module
(pictures details to follow...)
Processor Technology 3P+S I/O board
(details to follow...)
Processor Technology 4KRA memory board
(details to follow...)
Processor Technology 16KRA Memory board
(details to follow...)
Processor Technology 64KRA memory board
(details to follow...)
Processor Technology 'Cuter' cassette I/O board
(pictures details to follow...)
Processor Technology Helios Disk Controller boards
The controller card set for the 'HELIOS' dual disk sub-system.
Processor Technology 'Music System' board
An uncomplicated little board (note the huge parts count), that indirectly caused one of the biggest stinks in the early days of file/program sharing.
The Processor Technology 'Music System' was one of the many programs for the P.T. SOL series of micro-computer that was distributed on cassette tape. (the standard storage medium for the SOL) Through the use of the board shown here, the software could play music in '4 part harmonies' into any standard tape recorder or amplifier. This was done by rapidly toggling the 'interrupt enable' line of the 8080/Z-80 processors, smoothing the output somewhat, and sending it off to the tape deck/amplifier. A bit 'buzzy' perhaps, although the software did attempt to add some variety to the output waveforms. It was for its time a major innovation in the field of computer music synthesis on small computers.
It did provide a reasonably straight forward format for music entry (for its time), which was greatly appreciated by all those who had been toiling with previous programs...
The software had no capability for storing song files onto any other medium as it depended on the on-board I/O handlers of the SOL for access to the cassette drive. With the increasing use of the CP/M Disk Operating System at the time, someone had a 'better idea'.
A revised version of the core software was created which added the capability to load/save songs on floppy disk through the CP/M O.S. This revised program and a number of new song files appeared in the CP/M User's Group Software Library as volume 39. Until that is until someone at P.T. got wind of it! Even in those early days, the software 'piracy' paraonia ran rampant! A few phone calls and threatening letters from legal departments later, and CP/MUG volume 39 simply ceased to exist. It vanished from the catalogs (with little/no real explanation) and the library continued with volume 40.
Now, far be it from me judge these events one way or another... Especially when you consider that the CP/MUG librarys were freely available... But it is rumoured that some copies of the infamous 'volume 39' still exist! (and the songs are pretty good too!) <grin/>
Processor Technology SOL-20 Main Logic board
(details to follow...)
Processor Technology SOL 'Personality Modules'
(details to follow...)
Processor Technology VDM-1 video display board
(details to follow...)
Radio Shack ASCII Keyboard
(details to follow...)
Seals Electronics 8k Memory board
(details to follow...)
Seals Electronics S-100 Prototype board
(details to follow...)
SemiDisk Systems Solid State Disk Emulator boards
A solid-state disk emulator board for S-100 (Altair) bus systems
Much more advanced than many similar boards of the time in that this board, rather than just being a somewhat reworked memory board actually looked (from a programming standpoint) like a disk drive.
The board had track and sector registers which you wrote to, and the hardware on the board mapped the data into the memory array. Actually very elegant, even to the point that the byte count in the sectors was automatically incremented each time your wrote to it.
Additionally, if you needed more capacity you could just add more cards and your 'drive' just gained more sectors!
The difference between the SemiDisk board on the left, and the SemiDisk II board on the right above is capacity. The SemiDisk provided 512k bytes of storage per board, while the SemiDisk II provided 2MB per card.
Battery backup was also available, and in fact was used quite reliably for many years on CBBS/NW.
Solid State Music S-100 Active Terminator board
(details to follow...)
SWTPC 6800 SS50 bus CPU Board
(details to follow...)
SWTPC SS50 bus Memory Board
(pictures details to follow...)
Tarbell Floppy Disk Controller board
Just about the most popular floppy disk controller made for the S-100 (Altair), largely due to the amount of documentation available, and the fact that the board could be configured to work with nearly any floppy disk drive made!
The controller also sported an on-board boot rom which greatly simplified getting a system up and running the first time.
Tarbell Double Density Floppy Disk Controller board
The Double Density version of the popular floppy disk controller board from Don Tarbell.
Thinker Toys 'Disk Jockey 1' Floppy Drive Controller Board
(details to follow...)
Technical Design Labs ZPU board
From TDL, this board provided connectors for installing in either early Altair or IMSAI chassis
TDL released a complete line of S-100 boards based around the Zilog CPU chip and supporting chips, plus software including an assembler, debugger, and monitor. Unfortunately, TDL fell into the mindset that claimed many other companies when they decided that they could 'do it better'...
In particular, the neumonics used by the TDL assembler did not match those of the Zilog assemblers, and TDL soon fell by the wayside...
Tektronix Parallel Encoded Keyboard
Introduced: 19??
Price at Introduction: $???.00
(details to follow...)
Thinker Toys 16k Static Memory Board
(details to follow...)
Vector prototyping card for DEC PDP/LSI systems
One of a long line of prototyping cards put out by Vector. This board could be used in nearly any DEC Q-Bus or Unibus based system.
Vector Graphic Z-80 CPU board
(details to follow...)
Xebec Hard Drive controller board for Apple II
(details to follow...)
put a component here
(details to follow...)
etc... (test equipment and other
computer related items)
Circuit Cellar IC Tester
Introduced: 1987
Price at Introduction: $145.00
Another of the projects from one of the most prolific contributors to the early years of BYTE magazine. Steve (won't mangle the last name here) later went on to found his own magazine: "Circuit Cellar Inc" which is still in publication.
This microcomputer based (the CPU is hiding under the LCD display) unit performs identification and functional (out of circuit) testing of most of the 74XX series of TTL ICs. (it does not perform speed testing however) It has been a very valuable piece of test equipment in the 'Garage' over the years and is still in use.
Digital Equipment Corporation DECtape Storage Rack
Just what it says...
Dranetz Model 626 Universal Disturbance Analyzer
Introduced: 19??
Price at Introduction: $???.00
(details to follow...)
Heathkit IM-2410 Digital Frequency Counter
Introduced: 19??
Price at Introduction: $???.00
(details to follow...)
Hewlett Packard Logic Comparator and Logic Clip
Introduced: 19??
Price at Introduction: $???.00
(details to follow...)
Paratronics, Inc. Model 100A Logic Analyzer
Introduced: ??? 19??
Price at Introduction: $???.??
Standard Memory: 16, 8 bit words
To properly work on classic equipment, sometimes you just want to have some classic test equipment!
The Paratronics Model 100A Logic Analyzer is a good example of this. In the tradition of the Altair, the Model 100 (predecessor of the 100A) was introduced as a construction article in one of the hobbiest electronics magazines.
The Model 100A accepts a data word of up to 8 bits as input, and can store up to 16 events around the trigger point which are displayed as numeric information on the display of a user supplied oscilloscope. (now admit it, you were wondering how this could be inexpensive enough for a construction article, were'nt you?)
And just to prove once again that you have to look under every rock to find the gems, you will note from the first pictures in this set that this unit was received into the collection as a kit (!)
Yes, even now we are still finding equipment from the early days of the microcomputer that have never been assembled, or as in this case never even removed from their original (Saran Wrap - really!) wrapping.
As I have a (somewhat more recent) logic analyzer in the collection, I'm still debating if I should assemble this unit, but I have some rather fond memories of assembling a few of these back when they first hit the market, so I suspect that I will. As I said earlier... Classic gear, Classic test equipment!
Pro-Log Corporation M822A - 8080A System Analyzer
Introduced: 19??
Price at Introduction: $???.00
Peer deep within the mind of the processor... and with this piece of test gear you can do exactly that!
With the test connector clipped over the 8080A microprocessor, you can have complete control over the functions of the processor and observe what it is doing, while it is doing it!
(more details to follow...)
ProtoPC Inc. Disk Exerciser Unit
Introduced: 1983
Price at Introduction: $???.00
A handheld unit that provided the 'exerciser' functions required to align 8 inch and 5 1/4 inch floppy drives when used in conjunction with alignment diskettes and an oscilloscope.
(more details to follow...)
Sanders Model 101 Modem Tester
Introduced: 19??
Price at Introduction: $???.00
You have got to love any piece of test gear that uses 'Nixie' tubes for its display... BTW: This unit is Serial Number #0004! (more details to follow...)
Tektronix/Sony Model 308 Data Analyzer
Introduced: 19??
Price at Introduction: $???.00
(details to follow...)
Tektronix Data Tape
Data tape in the DC-600 form factor for the Tektronix 405x series graphics computers.
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