A Commodore PET is not a machine to buy on a vague description and one dark photograph. Its all-in-one cabinet makes it an instantly recognisable centrepiece, but the same design hides a CRT, mains supply, keyboard, logic board and often decades of hurried repairs. For collectors, the attraction is obvious: this is the machine that put Commodore firmly into the late-1970s personal computer market. The buying decision, however, should start with model identification and condition, not nostalgia.
Know which PET you are looking at
The PET family is broad enough that a listing simply described as a “Commodore PET computer” tells you very little. Early 2001-series machines are historically significant, particularly examples with the distinctive chiclet keyboard, integrated cassette deck and small 9-inch display. They are also among the least practical PETs to put into regular use, and complete unmodified examples command attention for good reason.
The later 3000 and 4000 series are often a more sensible entry point. They generally offer the full-travel keyboard collectors expect, while 4000-series machines with the larger 12-inch screen are particularly usable. A 4016 or 4032 is a familiar target for UK and European collectors, although regional variants, keyboard layouts and mains arrangements must be checked rather than assumed.
At the higher end, 8000-series machines such as the 8032 and 8096 offer 80-column capability and are well suited to anyone interested in business software, CP/M-era peripheral setups or serious PET programming. The 8296 is a notable later model, but it is not automatically the best purchase just because the number is higher. Availability, condition, local mains compatibility and the software or peripherals you intend to use all matter.
A useful rule is to buy the PET that fits your collecting aim. If you want an early Commodore landmark, originality may outweigh usability. If you want a machine for regular BASIC sessions and disk loading, a clean 4032 or 8032 with known-working storage is usually the more rewarding proposition.
Commodore PET collecting guide: condition before rarity
Rarity can inflate asking prices, but a rare PET with a damaged CRT or incomplete logic board can become a long and expensive parts search. Ask for clear images of the front badge, keyboard, rear label, internal boards and all connectors. The serial label often helps establish the precise model and market version, while the internals reveal whether the machine is complete and plausibly original.
The display deserves close attention. A PET that powers up with a bright, stable screen is reassuring, but a photograph of a BASIC prompt does not prove the machine will remain stable when warm. Screen burn, a dim raster, excessive flicker, a collapsed image or a persistent bright line all require investigation. CRT work involves high voltages, so collectors without experience should budget for specialist help rather than treating it as a casual repair.
Keyboard condition is equally significant. Missing keycaps, cracked stems and non-working keys reduce value, especially on early units where correct replacements are difficult to obtain. Test every key where possible, including cursor controls, Shift, Run/Stop and the keypad on applicable models. A keyboard that looks clean but produces intermittent characters may need more than a simple clean.
The internal cassette deck is another point where originality and practicality diverge. A complete early PET with its original Datassette mechanism is more collectible than one with an empty aperture. Yet an old deck may need belts, cleaning and alignment before it will reliably load tapes. If your aim is regular use, a modern storage solution can be sensible, but keep any original parts with the machine and avoid irreversible cabinet alterations.
Watch for hidden repair history
Period repairs are part of vintage computing, not automatically a reason to walk away. Socketed replacement RAM, dated service labels, tidy capacitor replacements and professionally fitted ICs can be signs of a machine that has been kept alive responsibly. The concern is untidy modification: loose wiring, scorched PCB areas, bodged power connections, cut traces without documentation or a board populated with random donor parts.
Ask whether the PET has been powered recently, how long it was run, and what was tested. “Lights up” is not the same as a tested working computer. Ideally, the seller can show a cold start, a short BASIC program, keyboard response and a successful load from the included storage device. For disk-equipped systems, request evidence that the drive reads a disk, not merely that its motor spins.
Originality, completeness and sensible upgrades
A PET with its matching monitor, correct keyboard, original power configuration and intact case is generally easier to value and resell. Original manuals, software, dust covers, printer cables and Commodore-branded peripherals can add meaningful appeal, particularly when they relate directly to the machine’s period use.
Do not dismiss a machine because it has a carefully documented modern modification. Replacement ROM adapters, RAM upgrades and storage interfaces can make a PET far more usable, and reversible upgrades are widely accepted within the hobby. The key question is whether the original hardware is retained and whether the modification has been installed cleanly.
Collectors should distinguish between an upgraded user machine and a museum-grade example. Paying a premium for untouched condition makes sense when the PET is genuinely early, complete and well documented. Paying the same premium for a common model with an untested board and a missing cassette assembly does not. A sympathetically restored machine can be a better buy than a supposedly original one that has been stored badly for forty years.
Check compatibility before buying peripherals
PET collecting often grows from one machine into a desk full of drives, printers, software and cables. This is where expensive mistakes happen. Commodore PET peripherals are not a single universal category: disk drives, IEEE-488 cables, printer interfaces, ROM revisions and software versions need checking against the specific PET model.
An IEEE-488 disk drive may be desirable, but it adds weight, shipping risk and another set of ageing electronics. A 2031, 4040 or 8050 can be an attractive companion depending on the system and collecting period, yet each should be tested independently. Dual-drive units are impressive, but a non-working second mechanism is not a minor cosmetic fault.
Software also needs careful reading. PET tapes and disks can be region-specific, business-oriented or intended for a particular screen width. Boxed titles are collectible, but inspect the actual media, inserts and manuals. A pristine box with missing disks is not a complete software item. For archivists and users, evidence that media has been read or imaged is worth more than an unverified claim that it is “probably fine”.
Value a PET as a complete proposition
There is no fixed PET price guide that remains accurate for long. Values move with supply, model desirability, cosmetic condition, working status and whether a buyer can collect locally. A fully working machine with a sharp display and documented service history can be worth substantially more than an identical-looking PET sold as untested.
Shipping deserves its own calculation. These are bulky CRT machines with fragile necks, heavy transformers and plastic cases that can crack under poor packing. Collection in person is often the safest option. If posting is unavoidable, insist on the monitor and any separate drives being packed with proper internal support, double boxing and suitable insurance. A low purchase price is quickly erased by transit damage.
When comparing listings, account for everything included: manuals, leads, disk drives, software, spare ICs and known faults. A cheaper bare PET may still be the right choice if you already own compatible equipment. For a first-time buyer, a complete tested setup often costs less overall than sourcing every missing part separately.
Buying and selling with useful documentation
For sellers, a precise listing attracts the right enquiries and reduces disputes. State the model number, serial number range if appropriate, keyboard type, screen size, mains voltage, included peripherals and faults. Photograph the startup screen, case corners, rear ports, internal boards where safe to do so, and any damage. Avoid calling a machine “mint” when it has yellowing, cracks or untested functions. Collectors respect accurate condition notes more than optimistic wording.
For buyers, save photographs and written details before collecting or arranging courier transport. They provide a useful record of condition and help identify components later. Specialist marketplaces such as SellMyRetro are particularly useful when you need a PET, an IEEE-488 lead, a serviceable disk drive or period software described by someone who understands the difference.
The best PET is rarely the first one that appears. Wait for an example whose model, condition and completeness match the collection you are actually building, then give it the careful testing and documentation that will keep it valuable long after the first green phosphor glow.