Commodore PET
Gallery
Commodore PET 2001 front view with keyboard
The original PET 2001 with its iconic all-in-one design and built-in monitor.
Commodore PET 2001 side profile
Side view showing the distinctive metal case design.
Commodore PET 2001 vintage advertisement
1977 marketing material for the revolutionary PET computer.
Commodore PET 2001
“The PET was the computer that started it all for Commodore. It wasn’t just a computer—it was a complete system that you could take out of the box, plug in, and start using. That was revolutionary in 1977.” - Chuck Peddle, Lead Designer of the PET and 6502 Processor
The Commodore PET (Personal Electronic Transactor) was Commodore’s first full-featured personal computer, introduced in 1977. As one of the first all-in-one personal computers, the PET combined a MOS 6502 microprocessor, display, keyboard, and tape drive in a single metal case. It was one of three pioneering personal computers introduced in 1977—alongside the Apple II and TRS-80—that would come to define the personal computing revolution.
The Birth of an Icon
The PET was developed against all odds in just six months by a small team led by Chuck Peddle. The name “PET” was originally an acronym for “Personal Electronic Transactor,” though Commodore later marketed it as the “Pet Computer.” The PET’s all-in-one design set it apart from other computers of the era, which typically required separate components for the computer, display, and storage.
Why the PET Mattered
- Complete System: All-in-one design with built-in display and storage
- Business Focus: First computer to be widely adopted by businesses
- Educational Impact: Revolutionized computer education in schools
- Technical Firsts: First computer with a built-in tape drive
Technical Specifications
Technical Specifications
- CPU
- MOS 6502 @ 1 MHz
- Memory
- 4 KB RAM (expandable to 32 KB) + 14 KB ROM
- Graphics
- Built-in 9" monochrome monitor, 40×25 text, 64×50 graphics
- Sound
- Built-in speaker (beep only)
- Storage
- Built-in Datasette (tape drive), optional 8" floppy drive
- Ports
- Parallel IEEE-488 (for printers/disks), cassette, ROM cartridge
- Operating System
- Commodore BASIC 1.0 in ROM
The PET Family
PET 2001 (1977)
- Original model with 4KB RAM
- Built-in Datasette
- Chiclet keyboard
- 9” monochrome display
PET 2001-N-8 (1978)
- 8KB RAM
- Full-travel keyboard
- Improved keyboard layout
PET 2001-8/B (1979)
- Business keyboard
- 16KB or 32KB RAM options
- Updated ROMs
PET 4000 Series (1980)
- 40-column or 80-column displays
- Updated keyboard design
- Up to 96KB RAM
SuperPET 9000 (1982)
- Dual 6502 and 6809 processors
- 96KB RAM
- Multi-language support
- Academic focus
The PET Experience
For Business Users
- Word Processing: Early business applications
- Accounting: Financial software
- Database: Business record keeping
- Reliability: Industrial-strength construction
For Educators
- Classroom Ready: Built for school environments
- Educational Software: Early CAI programs
- Computer Literacy: Introduced programming to a generation
For Programmers
- BASIC 1.0/2.0/4.0: Evolving programming environment
- Machine Language: Full hardware access
- PEEK/POKE: Direct memory manipulation
Technical Deep Dive
CPU and Memory
- MOS 6502: 1 MHz processor
- Memory Map:
- 0x0000-0x8FFF: RAM (up to 32KB)
- 0x9000-0x9FFF: I/O
- 0xA000-0xBFFF: Optional ROM
- 0xC000-0xFFFF: ROM (BASIC, KERNAL)
Video System
- Display: 9” monochrome monitor
- Text Modes: 40×25 or 80×25 characters
- Character Set: Upper-case only (original models)
- Graphics: Block-based, 64×50 resolution
Storage
- Datasette: 300 baud tape storage
- Floppy Drives: 2040, 2040, 8050 (100KB-1MB)
- Hard Drives: Rare 8” Winchester drives
The PET Legacy
Commercial Success
- Sales: Over 1 million units sold
- Markets: Strong in education and business
- Longevity: In production until 1982
Technical Influence
- All-in-One Design: Inspired future computers
- BASIC Language: Set standards for future implementations
- I/O System: IEEE-488 became an industry standard
Collector’s Item
- Rarity: Early models highly sought after
- Value: $500-$5,000 depending on model and condition
- Restoration: Active community of restorers
Notable Software
Business
- SuperWriter: Word processor
- SuperCalc: Spreadsheet
- Data Manager: Database
Education
- Classroom Manager
- Typing Tutor
- Computer-Assisted Instruction
Games
- Space Invaders
- Pac-Man
- Lunar Lander
- Star Trek
Technical Notes for Enthusiasts
Hardware Revisions
- Original PET (2001): 4KB, chiclet keyboard
- 2001-N-8: 8KB, full keyboard
- 4000 Series: 40/80 columns, updated design
- SuperPET: Dual CPU, academic focus
Common Issues
- Keyboard: Chiclet keys can fail
- RAM Chips: 2102 RAM failures common
- Power Supply: Can fail and damage computer
- CRT: High voltage components
Modern Upgrades
- RAM Expansions: Up to 256KB
- Storage: SD card interfaces
- Video: Composite/RGB output
- Networking: Ethernet interfaces
The PET Today
Emulation
- VICE: Full PET emulation
- MAME: Arcade emulation with PET support
- FPGA: Hardware-accurate recreations
Community
- User Groups: Active worldwide
- Forums: Online communities
- Events: Vintage computer festivals
Development
- New Software: Still being created
- Hardware: Modern peripherals
- Documentation: Extensive online resources
Did You Know?
- The PET was originally going to be called the PET 2001 to evoke the movie “2001: A Space Odyssey”
- Early PETs had a “deadly poke” (POKE 59458,62) that could damage the CRT
- The PET was used by the US Army for artillery calculations
- The PET’s case was designed to meet California earthquake standards
- The original PET’s keyboard was so bad that some users attached external keyboards
The PET in Popular Culture
- Featured in the movie “Real Genius” (1985)
- Appeared in the TV show “WKRP in Cincinnati”
- Used by Stephen King to write several novels in the 1980s
- Displayed in the Smithsonian’s National Museum of American History