The First Hobby and Home Computers: Apple I, Apple II, Commodore PET, and TRS-80

“The first Apple was just a culmination of my whole life.” – Steve Wozniak, Co-Founder Apple Computers Following the introduction of the Altair, a boom in personal computers occurred, and luckily for the consumer, the next round of home computers were considered useful and a joy to use.

In 1975, Steve Wozniak was working for Hewlett Packard (calculator manufacturers) by day and playing computer hobbyist by night, tinkering with the early computer kits like the Altair. “All the little computer kits that were being touted to hobbyists in 1975 were square or rectangular boxes with non understandable switches on them…” claimed Wozniak. Wozniak realized that the prices of some computer parts (e.g. microprocessors and memory chips) had gotten so low that he could buy them with maybe a month’s salary. Wozniak decided that, with some help from fellow hobbyist Steve Jobs, they could build their own computer.

On April Fool’s Day, 1976, Steve Wozniak and Steve Jobs released the Apple I computer and started Apple Computers. The Apple I was the first single circuit board computer. It came with a video interface, 8k of RAM and a keyboard. The system incorporated some economical components, including the 6502 processor (only $25 dollars – designed by Rockwell and produced by MOS Technologies) and dynamic RAM.

The pair showed the prototype Apple I, mounted on plywood with all the components visible, at a meeting of a local computer hobbyist group called “The Homebrew Computer Club” (based in Palo Alto, California). A local computer dealer (The Byte Shop) saw it and ordered 100 units, providing that Wozniak and Jobs agreed to assemble the kits for the customers. About two hundred Apple Is were built and sold over a ten month period, for the superstitious price of $666.66.

In 1977, Apple Computers was incorporated and the Apple II computer model was released. The first West Coast Computer Faire was held in San Francisco the same year, and attendees saw the public debut of the Apple II (available for $1298). The Apple II was also based on the 6502 processor, but it had color graphics (a first for a personal computer), and used an audio cassette drive for storage. Its original configuration came with 4 kb of RAM, but a year later this was increased to 48 kb of RAM and the cassette drive was replaced by a floppy disk drive.

The Commodore PET

The Commodore PET (Personal Electronic Transactor or maybe rumored to be named after the “pet rock” fad) was designed by Chuck Peddle. It was first presented at the January, 1977, Winter Consumer Electronics Show and later at the West Coast Computer Faire. The Pet Computer also ran on the 6502 chip, but it cost only $795, half the price of the Apple II. It included 4 kb of RAM, monochrome graphics and an audio cassette drive for data storage. Included was a version of BASIC in 14k of ROM. Microsoft developed its first 6502-based BASIC for the PET and then sold the source code to Apple for AppleBASIC. The keyboard, cassette drive and small monochrome display all fit within the same self contained unit.
Note: Steve Jobs and Steve Wozniak at one point in time showed the Apple I prototype to Commodore, who agreed to buy Apple. Steve Jobs then decided not to sell to Commodore, who bought MOS Technology instead and then designed the PET. The Commodore PET was seen at the time to be a chief rival of the Apple.

In 1977, Radio Shack introduced its TRS-80 microcomputer, also nicknamed the “Trash-80”. It was based on the Zilog Z80 processor (an 8-bit microprocessor whose instruction set is a superset of the Intel 8080) and came with 4 kb of RAM and 4 kb of ROM with BASIC. An optional expansion box enabled memory expansion, and audio cassettes were used for data storage, similar to the PET and the first Apples. Over 10,000 TRS-80s were sold during the first month of production. The later TRS-80 Model II came complete with a disk drive for program and data storage. At that time, only Apple and Radio Shack had machines with disk drives. With the introduction of the disk drive, applications for the personal computer proliferated as distribution of software became easier.

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