More build-in characters on the Aquarius would have been possible

[Aquaman]

Why did the designers of characters on the Aquarius character ROM make at least 40 interchangeable graphics? Did they perhaps forget about the color possibilities of the Aquarius, which makes it possible to invert graphics with the right use of color? If they had taken this into account another 20 or more unique graphical designs could have been put on the build-in character set. The only advantage I see of having these extra graphics, is when only the standard colors are being used, but as a promoted game computer this seems unlikely to be intended!

[jaybird3rd]

It didn't make much sense to me, either, until I understood why the "bloxel" characters were laid out within the character set in the way that they were. It's a pretty interesting solution: put simply, they made it easier for the programmers to turn the bloxels within a character on or off, as if they were individually addressable and programmable pixels, sacrificing a few "duplicate" characters in the process.

 

I added a detailed note about this aspect of the character set to the Astrosmash trivia entry in the Aquaricart, since that game in particular makes heavy use of bloxels. Here's part of what I wrote:

 

Fortunately, Mattel's artists had the foresight to include a collection of general-purpose block character cells. These cells were divided into two-by-three grids of "pixels" (or "bloxels", since they were larger than the actual screen pixels), and every possible combination of bloxels was included as a separate cell. By carefully combining these cells, a programmer could create the illusion of a fully programmable, low-resolution, pixel-oriented display.

 

These cells were arranged within the character set in an interesting way. Every bloxel in the 2x3 grid is given a value:

 

+----+----+
|  1 |  2 |
|----|----|
|  4 |  8 |
|----|----|
| 16 | 32 |
+----+----+

 

By determining which bloxels need to be "on" or "off" within a given cell, and by computing the total value of the bloxels which are "on", the programmer can locate the corresponding character within the character set using a simple calculation: if the total value is less than 32 (that is, if the last bloxel is "off"), it is added to the number 160. If the total value is equal to or greater than 32 (that is, if the last bloxel is "on"), it is added to 192. In both cases, the result is the corresponding character code.

 

So, when you use a PSET command in BASIC, the computer is actually determining which character cell on the screen the specified "bloxel" should appear in, checking the character code already in the cell (if any), and calculating which character to replace it with to make it appear as if the new "bloxel" is being individually turned on.

 

Of course, the "illusion" of (somewhat) higher-resolution graphics is shattered when you try to change the color of an individual bloxel: colors can only be applied at the character level, and you only get two colors per character. At least you can combine as many colors as you want on a single line, which still allows you to create some fairly colorful displays despite the limited color resolution.

[Aquaman]

It didn't make much sense to me, either, until I understood why the "bloxel" characters were laid out within the character set in the way that they were. It's a pretty interesting solution: put simply, they made it easier for the programmers to turn the bloxels within a character on or off, as if they were individually addressable and programmable pixels, sacrificing a few "duplicate" characters in the process.

 

I added a detailed note about this aspect of the character set to the Astrosmash trivia entry in the Aquaricart, since that game in particular makes heavy use of bloxels. Here's part of what I wrote:

So at the end it is all down to math! Still a couple of more characters would have been nice !

[jaybird3rd]

So at the end it is all down to math! Still a couple of more characters would have been nice !

True. Unfortunately, if they had removed the block characters that could have been created by inverting the others, replacing them with other characters, it would have made the programming much more complicated: the programmers would have had to figure out if a block character they needed was one of the "inverted" ones, and if it was, they would have had to use it completely differently from the other characters (by finding the inverted character in the set, inverting the colors, etc). They must have decided that losing a few characters was a worthwhile tradeoff, and they were probably right. The real solution is to add multiple character sets, which I will hopefully be doing with my "SuperFont" upgrade.