Canon X-710 Plotter

I've always sort of wanted to own a plotter, but never went for full pro equipment. Guess I knew I'd just want to play with one. Plotters at home never caught on that much, as the other printing techniques were eventually able to produce similar results on the A4-size. Still, there's something elegant about that paper-traversing pen.

Well, here's one tiny toilet paper holder plotter for Canon X-07. It came together with yet one more Canon X-07 computer. One of the neat ideas was that grey binder that covers the machine. Now, here the very same design has been simply extended to cover both the computer and the plotter, and it looks simply ridiculous. For comparison, Canon X-07 and a Canon X-07+plotter side by side:

It will probably fetch $1000 from eBay at 2025.
Incidentally, don't think the X-07 is worth more than 40-50$, please.

The plotter is simply packed together with the computer, and it has to be connected to the X-07 with an external parallel cable. The connector is an 8-line wide bus, activated with a strobe signal. The plotter prints straightforwardly any text you throw at it, except in the drawing mode text commands are used to move the pen around.

PSU-modded. I suppose the mechanism is identical between CBM, Sharp etc. models.

First, I had to do the power supply mod to make the plotter work without the battery. Canon apparently aimed to create a fully portable system so the power supply included is really a "battery charger".

The pens that came with the plotter had dried a long time ago, and attempts at rejuvenating them with water have failed despite coughing up some ink. So, I ordered some plotter pens from eBay. These are old too, but supposedly never opened. (They cost more than the plotter. Some things never change). They are not perfect, but still, I'm surprised they work at all.

Cleverly, the pens are contained in the paper roll axle. (centimetre grid)

The graphic mode has to be activated with LPRINT CHR$(18). Subsequently, commands such as LPRINT "M0,0" will move the pen to coordinates 0,0 with the pen up. LPRINT "D100,100" will bring the pen to coordinates 100,100 with the pen down, drawing a line in the process. Pressing Reset on the plotter will reset the pen and takes the plotter back to the text mode. The new 0,0 coordinate will be at the new pen position.

At the moment, it seems my plotter has some difficulties changing the pen colour reliably. It may be because I somehow wrecked the delicate parts of the pen revolver when replacing the pens. Oh well.

Note that here the black pen had some trouble when moving right.
The bottom left corner is "bolder" from multiple passes.

From what little I have seen this tiny plotter is able to keep the coordinates very well. The printer uses a mechanism to perforate the paper slightly from the edges. These tiny holes are at the same time used for holding the paper in position (much like matrix printers use the ready-made holes to align the paper).

It appears that most of these small plotters of the era used the same ALPS mechanism with pens of same size, so Sharp, VIC, Casio and Canon plotters might have interchangeable parts.

But who was the intended user for the plotter, or for that matter, the strange Canon X-07+plotter combo? Imagine in 1983, a businessman pulling it out of the bag during a meeting, throwing together some lines of BASIC that plot out the latest sales curve projection...

It's a big world out there, son, and you've got to compete. No time chasing balls of string.
With the Canon pltoter, you can have that crucial edge...

Canon X-07

A little beauty, this one. The computer is book-sized and fits into a VHS-case sized plastic binder. It offers pretty much what a home micro would have around 1983, except in a very small portable size. The language is Microsoft BASIC, which was state of the art at the time. Well, the memory is not that impressive, only 8K of which roughly 6 are available to BASIC.

Despite the looks the X-07 is not really a scientific calculator. For example, the math symbols are not directly available but behind SHIFT-combinations as on an ordinary micro. It's of course possible to write some calculator software! The BASIC offers very direct access to screen features such as text and bitmap graphics with commands like PSET, LINE, CIRCLE and FONT$ which can be used for the 5x8 user character definition. I suppose for graphing purposes these are fine and to me this is more flexible than the clunky TI-BASIC found in Texas Instruments calculators, even the newer ones.

On the negative side, the connectors are a bit non-standard. For a tinkerer it's nothing, but of course an ordinary RS232 port would have been nice (It's not even that much smaller). Sadly the resolution is very small, 120x32 pixels, and the display is not backlit. Apparently there's a display adapter which would give an 8-colour display on a television. This would make X-07 even more interesting, although then it would no longer be portable.

The Z80-compatible chip is likely to be on the slow side to conserve power, my hunch is 1mhz. (Edit: Nope, it seems the NSC800N variant is 2.5mhz) Printing and graphics commands are quite slow via BASIC. I don't know how long the battery life is, but I'd assume that the display is not that greedy.

What I like about this machine is that the "booting" time is non-existing. The RAM "disk" is permanent as long as the batteries last. The user chooses a suitable portion of the memory for the RAM files, and code snippets can be stored and retrieved via SAVE and LOAD commands. DIR brings up the file list. It's also possible to RUN "filename" to execute a file without loading it into the text memory.

The RAM is battery-backed and it's also possible to put the display to SLEEP and continue later from where you left. There are some interesting possibilities for using this computer to "upload" tiny pieces of data via the RS232, and I might be tempted to try this later. An "autobooting" command can also be created, for running the program in memory, for example. This makes me think the computer is meant to be customized into a variety of one-purpose devices, possibly a controller for industrial machines.

The eight bits between the nybbles. We've seen this before.

Tape options are of course available and using Audacity on my MiniMac I could store and reload a BASIC program. The format seems straightforward enough and if there's nothing about it on the internet I might examine it a bit further. (Edit: Actually, it's all in the manual. Silly me. Also, there's a webpage about the tape formats.)

I feel positive about this tiny computer. The build quality is high and the Canon competence in calculators also shows here. Everything there is, is pretty well made and thought out.


The memory upgrade:

A Toshiba TC5565PL-15 memory chip adds 8K memory, to a total of 16K. The whole system may need resetting before the memory becomes active. The RAMdisk use becomes a bit more reasonable with this expansion.

How to build an RS-232 cable between Canon X-07 and a PC:

Edit: I'd recommend NOT connecting this serial port directly to a Mac/PC! They have a different voltage level.

It is quite fortunate that a piece like the one below can be stuck into the existing port, by ever so slightly twisting the pins. However, the pin order is not standard so a special cable or an adapter needs to be built.

The diagram below shows how to connect between two port types. A cable between two Canons would of course be symmetrical. Note that the numbering in Canon port follows the order in the manual. (1=LTxD, FG, N.C., TxD, RxD, CTS, RTS, SG, VBB) 

The manual also tells the signal level is not standard, but this did not seem to cause problems when connecting between Canon and a Mac. I just went away and tried, although they should not be compatible. I'd be careful. What I see the RS232 in Canon is likely to be TTL level ("5v") whereas serial ports can be 12v. I suspect modern computers and USB/serial adapters may be accommodating, but I'd be wary of connecting different kinds of computers.

The serial port, seen from the outside.

On the Canon end, you do this to set the port:

INIT #1,"COM:",2400,"B"

4800 is the highest speed. The "B" combines the various parity and bit length parameters into a single letter. B seems to work ok with 8 bits, no parity.

After initializing the channel you can:

PRINT #1,"HELLO" to send a string of characters.

...or OUT #1,65 to send characters out.

...or LIST #1 to output the BASIC listing in ASCII.


Some good resources:

The Canon is quite well documented on the net. There seems to be a whole scene focusing on collecting and enthusing about hand-helds, calculators and even digital wrist watch computers.

Here's a page that tells everything you need to know about various peripherals and extension cards:

http://gtello.pagesperso-orange.fr/cx07_e.htm

Programs for creating tape files:

http://www.mvcsys.de/doc/casioutil.html