Mad Teddy's Humpty Dumpty book

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The Humpty Dumpty Book

If you've arrived here via my Mathematically-based computer graphics page, presumably you'll have read my misty-eyed ramblings about the "good old days" when the Commodore 64 ruled, OK.

In the early 1980's, the "IBM PC" was in its infancy. Its operating system was an early version of DOS. It was a monochrome device (green on black, usually). For a sound system, there was a tinny little speaker built into the case which didn't do much more than "beep" - unless you knew some machine code and could program it to do something more exciting.

Worst of all, the PC was - for most practical purposes - merely a text-based machine. It had very little provision for graphics, which were seen at the time as a somewhat frivolous extravagance.

Click here to read a very presentable history of the PC, which goes into these matters in considerable depth.

The Commodore 64 was the very antithesis of the PC. Even though its screen's resolution was much less than that of the PC, every single pixel it did have was available to the programmer - with a choice of sixteen possible colours.

That's not to say it was necessarily easy to do graphics on the C64. There were a few different things you could do, which all involved PEEK's and POKE's (or their machine code equivalents) to some extent - but if you were determined and persistent enough, you could manage it. There was no shortage of literature around (books and magazine articles) from which to learn the basics.

Just as exciting was the C64's sound system! Built into the machine was a SID chip (an acronym for Sound Interface Device). This little piece of magic was a fully functional three-voice synthesizer with which it was possible to produce some quite extraordinary effects, including ring modulation and synchronization. As with graphics, there were tricks to learn; but the rewards were there if one made the effort - and, again, there were plenty of articles to read and examples to type in.

The C64 was a fun machine from which the serious hobbyist could learn a lot about both programming and hardware. If you were already an electronics buff (as I was), and thus could understand basically how the machine was put together, playing around with it was sheer heaven. Quite unlike the dreary old PC, this was a godsend for the "tinkerer".

To produce artwork with high-resolution graphics, there were several software packages one could purchase. Probably the best known was "Doodle"; there was also one with the very silly name "Blazing Paddles". As a dedicated Baked Bean fan, I was most amused by the obvious allusion to the brilliant Mel Brooks film "Blazing Saddles". (If you haven't seen the film, make an effort to do so - then the significance of the last sentence will become clear. Update, 15th October 2010: Alternatively, you could just type "blazing saddles campfire scene" into Google, and thus have access to some YouTube video clips of the relevant sequence... )

I bought a rather good graphics package called "The Advanced OCP Art Studio", with which one could produce pictures in either high-resolution or multicolour mode (which allowed for up to four colours within an 88 pixel block but with double-width pixels). With that, I produced the following hi-res graphic, which is the main inspiration for this page:

Now, if you're paying attention, the next question which should spring to mind is: "How do you get C64 graphics into a PC?"

In fact, there are ways to do it via software. There are websites which are dedicated to making the modern multimedia PC into a C64 emulator - right down to the slow old 1541 disc drive!

This is something I'd like to do at some stage; but for the moment, I've used a more "low-tech" approach to produce the graphics on this page.

You may have noticed that the Humpty Dumpty picture above looks a bit scrappy. This is because it has had to go through a number of steps to get here, each one of which introduces imperfections.

In 1988, about three years after I bought the C64, I purchased an MCS810 printer for it. Advertisements for this printer had appeared in various Commodore-specific magazines under its original name of Okimate 20. It claimed to be able to print both text and graphics in vibrant colour, and I was intrigued with the idea.

Click here to see a picture of this little machine. (To get any sense out of the three links to other photos at the bottom of the page, you'll need to have Javascript switched on. )

A strange beast, it used a special ribbon which came in what looked a bit like an audio cassette only about twice as big. You could get both black and colour versions.

The ribbon was a transparent thin plastic strip with a wax coating on one side. The printer's head ran along the non-waxed side from left to right, its pixel-sized heating elements melting the wax onto the paper according to the image transmitted to it from the C64. Then the head would return to the left, and the ribbon would be shuttled along to a fresh bit ready for the next operation.

When printing monochrome with a black ribbon, the paper would be rolled up a line at the end of each operation. However, when printing in colour, the machine seemed to take on a life of its own - a very odd thing to see!

For colour printing, three passes were required for each line. The ribbon contained short strips of wax in each of the three primary pigment colours yellow, magenta, and cyan (in that order, as I recall). For each line, the printer would move the first colour strip into place and print the line. Then the head would move to the left and the ribbon would be jiggled along to the next colour strip, and the line would be reprinted. This process would be repeated for the third colour. Finally, the paper would roll up ready to start the next line, the head would return to the left, and the ribbon would clatter along to the next waxed segment of the first colour.

The first time I printed a colour graphic, I thought the gadget was going to shake itself to pieces!

As you may imagine, there were many things that could go wrong: several moving parts which needed to act exactly in step; the electronics which controlled the movement; and the heating elements in the head.

When it worked as it was supposed to, it produced very attractive printouts (as this page testifies). However, when it misbehaved, the results could be a bit of a disaster.

Eventually, the head burned out. With great difficulty, I managed to obtain a replacement, which worked well enough for a while - but eventually, other things started to go wrong, and the day came when I just had to write the printer off.

I think it was a clever idea, but perhaps ahead of its time. Ink-jet printers (a related technology, in some ways) were just being developed around then, and were nowhere near as ubiquitous as they are now - and they also had their fair share of problems. (It's always seemed to me that printers, with their myriad moving parts, are the weak link in any integrated computer system, and probably always will be.)

However, looking on the bright side, I did get some impressive results with the old thing before it died, and I had the presence of mind to keep them. Each being about the size of a standard photo print (13.4cm 10.3cm), they found their way into a good-quality photograph album.


My tribute to Ringo Starr's famous kid's song, "Octopus's Garden"

The pictures you see in this page were scanned from my printouts, resized using DISPLAY to make them a suitable size for posting here, and finally tidied up a bit around the edges by cropping, also with DISPLAY.

As you can see, they're not perfect. It's not too hard to see where the individual lines are. Also, you may notice that sometimes there's a slight "checkerboard" look about some of the colors (for example, the octopus, seawater, and sand in the above picture, and the sky and banner background in the Humpty Dumpty picture). This occurs because the printer used a very simple form of dithering for some lighter colours, whereby one-quarter of the pixels were left white. (Actually, when it works well, it's rather attractive.)

I produced quite a few pictures with the Advanced OCP Art Studio. These were fun to do, and enabled me to learn valuable skills for later use with software such as Neopaint. However, my main interest with regard to graphics was to generate mathematically-based images like surfaces, biomorphs, and zooms of the Mandelbrot Set.

Eventually I did, and some of the results follow. The photograph album began to fill up. One of my kids, not much more than a toddler at the time, took a great interest in the pictures; for a while, a regular activity we shared was to browse through the album - which thus came to be known as the Humpty Dumpty Book.

This picture - a kind of hybrid of graphics and artwork - strikes a chord in me. To my mind, it has a mystical quality. I produced it using Simons' Basic, and named it "Evening in Kalos". Something in me yearns to visit this place, somehow...

Here's a monochrome radiolarian. (If you've visited my Fractals #2: Biomorphs page, you'll have seen a PC BASIC version of this pattern.)

Notice that it's somewhat stretched in the vertical direction. There may be several factors contributing to this, including the fact that the aspect ratio of the C64 screen (320/200, i.e. 1.6) is different from that of PC BASIC's SCREEN 12 graphics mode (640/480, i.e. 1.3333); and there may be some distortion generated by the MCS810 printer itself. I used DISPLAY to attempt to correct this; shrinking the vertical dimension down to 80% gives a quite good result:

I haven't bothered to do anything similar with any other pictures on this page, preferring simply to present them essentially as they emerged from the printer.

Here's an attempt to show ripples on a pond, caused by dropping in a small object such as a pebble:

Success with this graphic led, years later, to my production on the PC of an animated gif of ripples moving outward. This is featured in my Animated surfaces page.

The next surface, of the form z = f(x,y), was generated in a similar way to the mountainous island near the bottom of my Animated surfaces page. I can't remember the details of the actual function; if I ever come across the equation, I'll post it here:

This is the first example in this page of a medium resolution, or "multicolour", picture. Because three colours are used, and in some instances all three are required within a particular 88 pixel block, it was necessary to use multicolour mode. This made all pixels double-width, so that each of the thousand (4025) 88 pixel blocks on the screen effectively became 48 blocks instead. Depending on a particular graphic, good results were sometimes thus obtainable; this is one which works rather well.

If you're an old C64 hand, this will all be second nature to you; if not, you may find it quite confusing. Surely hi-res pictures like Humpty Dumpty and Octopus's Garden (above) have more than two colours...? Indeed they do - but there are only two colours within each of the thousand 88 blocks! A good C64 artist learned to work within this limitation, which thus became invisible to the casual viewer.

Interestingly, a similar effect did manifest itself with the PC when I was doing some deep zooms into the Mandelbrot set, years later. If you go to too many decimal places, you go beyond the computer's capability to distinguish between numbers, and the result is a compromised graphic. You can see an example, with commentary, by clicking here. (Scroll about halfway down the page.)

Of course, a lot has happened since the early 1980's. A decade later, the multimedia PC arrived on the scene, with excellent graphics capabilities - exceeding those of earlier computers, including the C64 - inviting programmers to take advantage of these new features.

Following are twelve small pictures each showing a C64-generated image from the Mandelbrot set. You can click on each of these to reach a page featuring a larger version (similar in size to those above) and some information about it. Each such page contains a link to yet another page featuring graphics generated on my PC of the same area (or, in the case of the ninth example, at least a very similar area).

Note that almost all of the pictures in these pages were generated in multicolour mode on the C64. Just one - in the sixth page - was produced using hi-res mode. More detail about matters arising are given in that page.


hd-m01.jpg                               hd-m02.jpg                               hd-m03.jpg                               hd-m04.jpg


hd-m05.jpg                               hd-m06.jpg                               hd-m07.jpg                               hd-m08.jpg


hd-m09.jpg                               hd-m10.jpg                               hd-m11.jpg                               hd-m12.jpg

To close this page in as incongruous a way as possible, here's yet another hi-res masterpiece I drew using The Advanced OCP Art Studio. One Christmas, as I recall, some of our friends received cards featuring this picture. It's a nativity scene, featuring the Three Kings of Orientar , the baby Jesus, Mary, a few lambs, and a somewhat exasperated-looking Joseph!


"We three kings of Orientar,
One in a taxi, one in a car,
One on a scooter, tooting his tooter,
Going to Zanzibar..."

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