Introduction to Hardware

You can see the hardware by looking at the Patent, Fig 1 (on the right here). This shows a picture of the watch itself, a picture of the LCD display, and a full circuit diagram (over a couple of sub diagrams).

The core processor is an SM510, part of the SM5 Sharp 4 Bit Microcontroller series. Unfortunately, I can't find the databook for this, but I have managed to find the SM511/2 Datasheet which is similar but slightly different.

Unusually the Patent gives a long list of information about the Microcontroller itself - good thing otherwise I'd be stuffed, and between this and the SM511/2 Datasheet I've figured out the minor details.

The SM510 has an LCD Driver built in, so lighting an LCD is just a matter of setting a bit in RAM. The processor takes care of the rest.

The LCD has a slightly unusual pattern for its graphics with the 6 x 6 "split filled circle" graphics. The 3.5 digit 7 Segment Display at the top is for the watch part (or displaying the score).

There is a 32,768Hz Crystal for accurately keeping time, and a Piezo buzzer. This is slightly unusual in that when turned on it provides a 4Khz tone automatically which you then modulate. It is possible to do this quite effectively. If you have a look at the Homebrew Channel F "Pacman" game, for example, despite it only having three tones it actually has a pretty good attempt at producing "Pacman" classic sounds.

Next time a little more about the Sharp Microcontroller which does all the work.

I'm not sure .....

if it ever existed. The Watchman watch I discovered is definitely in the patents database - but whether it ever existed, in prototype or finished form I don't know.

There are a whole heap of things that are right on the border of existence - the Atari Space Invaders handheld on the right (COP 420 processor, 32 x 32 LCD apparently) probably existed in prototype form, but was certainly never released. Or it could just have been a box mockup.

It's not as if it is completely off the wall. The patent (see links box) was filed by Jay Smith III on behalf of Smith Engineering. Jay is the designer of both the Microvision and the Vectrex.

So I would guess it was either a fully worked design or prototype that was built - the whole design is certainly plausible and is given in quite impressive detail but never got built in any quantity or released, as far as I can tell.

So , anyway I plan to create it to a 'playable' level - in emulation, not a watch obviously. It has all the retrogoodies I like - it's fairly ridiculous, it's very low level technology (4 bit CPU) and it's original :)



There's all sorts of interesting things in the database. There are the original designs for the Microvision, Total Control 4, Entex Select-a-Game amongst others. There's some highly speculative designs here as well that probably were never built and some rather wild and wonderful things that were.

I was quite tempted to use the "Invisible Alien Neutraliser" patent but I couldn't think of anything to do with it. It is basically a handheld console with a phototransistor attached, it can read the ambient light level. The amazing thing about this is it actually was made ........... one wonders about the sense involved in releasing such a thing :)

Anyway, in the next post I will expand on the hardware a little.

Watchman is a ...... what ?

Well, yes, this is something really obscure and wierd again. Well, I like wierd and obscure bits of hardware.

This thing on the right is an actual "original" Watchman made by Tomy, the predecessor of the machine I'm developing for. Like most "Watches with Games" (see these guys for a ridiculously long list) these ones are single game watches - the most common one was a bowling game.

There are a lot more things like this - Game and Watches (this is a Nintendo classic). These are much better games, but not actually really useable as watches. You can't really fasten one to your wrist - it is more like "Game and Portable Small Clock".

This too has the major issue that the game itself is a one shot based on the LCD - you can't do a different game with it really.


The Watchman I am going to write some games for is more like the above watch in looks - but its display is just about flexible enough to support different games. The original appears to have had four games. There is one major problem with this whole rather mad thing though, which I'll deal with next time.