Teardown: VTech PreComputer 1000 is an Iconic PC in a Toy Wrapper

Back in the days before kids could be placated with a $50 Android burner phone, many a youngster was gifted a so-called “educational computer” to keep them occupied. Invariably looking like a fever dream version of the real computer their parents didn’t want to let them use, these gadgets offered monochromatic exploits that would make Zork look like Fortnite. Due equally to their inherent hardware limitations and the premise of being an educational toy, the “games” on these computers often took the form of completing mathematical equations or answering history questions.

The VTech PreComputer 1000 is a perfect specimen of this particular style of educational toy. Released in 1988, it was advertised as a way for pre-teens to become more comfortable with operating a real computer; since at that point, it had become abundantly clear that the coming decade would see a beige box on every professional’s desk. Its full-size QWERTY keyboard was specifically mentioned in the product’s accompanying literature as a way to get young hands accustomed to the ways of touch typing.

Words of wisdom from the PreComputer 1000’s manual.

By the mid-1990s these devices would have progressed far enough to include passable text-to-speech capabilities and primitive graphics, but the junior professional who found him or herself seated in front of the PreComputer 1000 was treated to a far more spartan experience. It’s perhaps just as well that this particular educational computer was listed as a training tool, because even in 1988, surely a session with this toy must have felt very much like work.

But that’s not to say the PreComputer 1000 is without its own unique charms. In an effort to help cement its role as a “trainer” for more conventional computers, VTech saw fit to equip the PreComputer with its own BASIC interpreter. They even included generous written documentation that walked young programmers through the various commands and functions. Even today, there’s something oddly appealing about a mobile device with a full keyboard that can run BASIC programs for better than 24 hours on batteries (even if they’re alkaline “C” cells).

Let’s take a look inside this more than 30 year old mobile device, and see how the designers managed to create a reasonable facsimile of actual computing on a kid-friendly budget.

Inspired by the Greats

If the layout of the PreComputer 1000 looks odd to modern eyes, it’s only because we’ve become accustomed to the now ubiquitous laptop form factor. But the iconic clamshell layout wouldn’t have meant much to a child in 1988. The Toshiba T1100, considered by some to be the first commercial “laptop” as we know it today, was only released a few years prior and wouldn’t exactly have been a common sight given its high price.

If the youngster had any first-hand experience with a computer, it would more likely have been with something along the lines of the Apple II, the Commodore 64, or the TI-99. As such, the PreComputer 1000 is clearly a nod to the popular “console” computers of the day, with perhaps more than a touch of inspiration coming from portables like the TRS-80 Model 100.

But as it turns out, the comparison to classic 8-bit computers is more than just cosmetic. Upon inspecting the PreComputer 1000’s PCB we can see that it’s powered by a Zilog Z84C0004PEC, a 4 MHz Z80 processor.

There’s also a Hyundai HY6116AP-10 providing 16K of RAM and a 1Mb VTech branded TC531000CP mask ROM that stores the computer’s firmware. Dotted around the relatively sparse PCB are various support ICs like the 74HC244AP line driver, HCF4011BE NAND gate, and the CD4508BE 4-bit latch.

Underwhelming I/O

Given the components on the PreComputer 1000’s main board, it’s safe to say that this is as much a real computer as any of the desktop machines from the late 1970s and into the early 1980s. For reference, the TRS-80 Model I that launched in 1977 only had a 1.4 MHz Z80 processor.

Unfortunately, VTech had to cut corners somewhere to get the price down to toy levels. So while it might have what would have been a desktop processor less than a decade previously, it was paired with a rather poor keyboard and display. Any potential the Z80 inside the PreComputer 1000 might have had is seriously hindered by the plodding ancillary hardware.

Waiting for text to march across the tiny 1×20 character LCD is pretty bad, but then, the displays on these computers are almost always quite poor. What’s really disappointing is the keyboard. It might have a full-size 60% layout, but unfortunately, it’s one of the most mushy and unresponsive membrane boards I’ve ever had the displeasure of using. Anyone who learned how to type on this thing must have been in for a real surprise when they got their hands on a proper keyboard.

Expanded Possibilities

Like many other educational computers, the PreComputer 1000 features an expansion slot that accepts cartridges which can augment the base capabilities of the system. In such an early example of the concept, the cartridges here simply increase the number and variety of questions that the system can ask the user, with available titles such as “Super Science” and “Bible Knowledge”.


The auction for this computer included a “Sports Trivia” cartridge, and inside we can see there’s nothing on the board but a few passives and another TC531000CP mask ROM. Interestingly, this means that each expansion cartridge has as much storage capacity as the computer itself. At least in theory, it would seem that the cartridges could have added a substantial amount of software had VTech wanted.

As we’ve seen in recent projects aimed at expanding the capabilities of similar “toy” computers, it could be that the expansion port on the PreComputer 1000 might one day see more extensive utilization should anyone in the community feel so inclined. While the LCD would remain a stumbling block, it’s hard not to be intrigued about the possibility of slapping a Collapse OS cartridge into the side of this machine.

A Piece of History

It’s easy to dismiss the VTech PreComputer 1000 as a simple child’s toy, but in its own way, it really is a legitimate piece of computing history. With its authentic Zilog Z80 processor, contemporary case design, and integrated PRE-BASIC interpreter, this device is like a microcosm of early 80s home computing.

The Constant Reader will likely know that most of the devices featured in these monthly teardowns end up as a pile of interesting or useful components destined for some as of yet unknown project. But such an unglamorous fate seems almost disrespectful this time around; as Dr. Henry Jones once said, an artifact like this belongs in a museum.

So the PreComputer 1000 will be going up on the shelf with the other interesting bits of technological bric-a-brac I’ve collected over the years. But I’ll also admit to ordering a second one on eBay that, with the help of modern contrivances and more than a little tinkering, may get a new lease on life. In the meantime, I’ll leave you with a brief video walkthrough of this interesting toy turned time capsule.