In 1971 the Kenbak-1, had 256 bytes of
memory
and was advertised for $750 in Scientific american.
The Kenbak-1 personal computer (1971) was designed by John V.
Blankenbaker
using standard medium-scale and small-scale integrated
circuits.
Designed to help teach programming, it relied on switches for
input
and lights for output. In 1973, after selling only 40
machines,
the Kenbak Corporation closed its doors.
---
The Intel MCS-4-based SIM4 (1972) was the first microcomputer.
The single-board SIM4-02 is shown, plugged into an Intel
MCB4
chassis along with a PROM programmer card.
 |
In 1973 Scelbi Computer Consulting Company
offers the first computer kit in the U.S.
Using a microprocessor, the Intel 8008,
for US$565, with 1KB programmable memory. An additional
15KB is available for US$2760. More
photos of the Scelbi computer. |
---
The French MICRAL (1973) was the first Micro-computer
sold (not in KIT) it's creator was François
Gernelle. The first non-kit computer based on a microprocessor
(the Intel 8008). Built in France, the Micral is advertised in the U.S.,
but is not successful there. Truong, founder and president of the French company
R2E tried to commercialize it but selling for $1,750, the Micral never
penetrated the U.S. market. Philippe Kahn designed the software. In 1979
Truong sold Micral to Bull.
 |
Truong: "The Micral in the beginning of
1973 was very rudimentary.
It had only 2 Kbytes of RAM, and could only be programmed in binary, and
that year we sold 500 of them only in France. In 1974 we (Philippe Kahn)
wrote the first assembler, so I could demonstrate the first complete microcomputer
using an Intel 8080 at the National Computer Conference [since replaced
by Comdex] in Chicago." |
---
| In July of 1974 the Mark-8 could have been Your
Personal Minicomputer, according to Radio-Electronics. |
 |
---
In 1986, the Boston Computer Museum
held a contest to elucidate the pioneers of microcomputers. Its
examiners, including Steve Wozniak, gave the title of the first
microcomputer to the Kenbak, which was designed in
1971 with discrete logic and not with a microprocessor.
The Micral was nevertheless recognized as the first
microprocessor-based personal computer, and the first
microcomputer largely and commercially distributed.
---
What was the
first personal computer?
The Altair 8800
UNIT SOLD = 10,000
Developers Edward
Roberts, William Yates and Jim Bybee spent
1973-1974 to develop the MITS Altair 8800. The price was going to
be $375, and contained , a board set, CPU, front panel (without
switches), four slot backplane and a 1K memory board with 256
bytes of RAM chips (not 256k). There was no case, no power supply
no keyboard, no display, and no auxiliary storage device.
The Altair 8800 helped start the Microcomputer
Revolution. In december
1974, Popular Electronics publishes an article by MITS
announcing the Altair 8800 computer for US$439 in kit form. It uses the Intel
8080 processor. The Altair pictured on the cover of the magazine
is actually a mock-up, as an actual computer was not available,
Railway Express loses Ed Robert's only prototype Altair computer,
en route to New York for review and photography for publishing by
Popular Electronics. Lauren Solomon, 12 year old daughter of Les
Solomon, publisher of Popular Electronics, suggests the name
"Altair" for Ed Robert's new microcomputer. Altair was
the name of where Star Trek's Enterprise was going that night. In
april 1975, MITS delivers the first generally-available Altair
8800, sold for US$375 with 1KB memory.
At that time personal computers were called "
hobbyist", "small-business", or "micro"
computers. The "Altair bus" used a connector with 100
pins and became known as the S-100 bus as more manufacturers
adopted it.
Read an Article from AMATEUR RADIO 73
about the ALTAIR
The Altair was followed by S-100 machines like the IMSAI.,
SOL, Morrow, Godbout/Compupro, Dynabyte, Cromemco, and Vector
Graphic. The market shifted from hobbyist to small business.
Machines like the Apple, Sol, Osborne, Kaypro were smaller and
had integrated keyboards and video were used in home, school, and
business. Later the IBM PC and it's clones replaced these
machines for business and personal use. The MITS/Icom Attache was
created to compete with the SOL and Apple but was not well known.
The Attache had a built in keyboard and video board and a
ten-slot S-100 bus.
MITS once had the ad on the Back cover of Byte magazine Byte lists the MITS
Altair 8800 as one of the Top 20 Small
Systems.
The Altair featured a BASIC written by Bill Gates and
Paul Allen. MITS was Microsoft's first customer.
The Altair had a front panel that allowed 8080 instructions to
be loaded into memory.
Some early Altair users had Teletypes with a papertape reader.
There was also a PROM board with 1702 PROMS (256 bytes).
A small boot loader could be run on the Altair to load larger
programs from paper tape.
Paul Allen and Bill Gates had access to a DEC computer with an
8080 assembler and emulator.
Programs like BASIC could be developed on the DEC and loaded
onto an Altair.
It was not long before Altairs had 5.25-inch and 8-inch Pertec
diskette drives.
The 4K BASIC grew to a 16K disk BASIC.
There was also an 8K BASIC that was on ROM (8*1K).
Pertec bought MITS and Icom and formed the Microsystems
Division. MITS stands for Micro Instrumentation and
Telemetry Systems and started the Micro-Computer
Revolution in Albuquerque, New Mexico.
MITS was founded by Ed Roberts. MITS first made radio control
devices, then calculators and later the 8800 and 8800a. The
machines were often sold as kits. They were not as pretty as the
8800b and had a weaker power supply . These early mainframes had
few peripherals or daughter boards. Early Altair users sometimes
used an ASR33 Teletype for a terminal.
Companies like Icom, Tarbell, and Micropolis filled the void
with diskette subsystems. MITS made a two-board controller set
for DC powered, Pertec FD-410 hard-sectored 8-inch diskette
drives. Later MITS and Icom used Pertec FD-510 and FD-514 SSDD AC
powered drives. These drives were 2/3 Height.
Pertec bought MITS and Icom to form PCC
MicroSystems Division. This division changed names and leaders
every six months and eventually killed the Altair. Pertec moved
away from the "Hobbyist Computer" image of the 8800a
and put the 8800b in a desk with the 3202 diskette sub-system and
made the MITS 300/25 Small Business System. By adding a Pertec
DC-3000 14-inch hard disk they made the 300/55.
GET THE Altair and Imsai Emulators
