From: Doug Ewell (dewell@adelphia.net)
Date: Fri Apr 02 2004 - 11:33:32 EST
Arcane Jill wrote:
> 0x80 if I remember correctly.
I know you've already corrected yourself, realizing that you were
thinking of the extended-ASCII character set used by the ZX Spectrum (TS
2068, IIRC), but just to finish this thought:
> There were sixteen block-graphics characters, remember? They each were
> subdivided into four quadrants, each of which could be either black or
> white, according to the low order four bits of the codepoint. The
> all-white block-graphics character was visually indistinguishable from
> space, but was NOT space.
I remember them well (and have a reference beside me anyway :). The
block-graphics characters could be inverted by adding 0x80, which means
that 0x80 was actually a solid *black* box. This had an especially
weird effect when juxtaposing the "gray boxes" 0x08 and 0x88, which were
both U+2592 but of opposite polarities, so they didn't line up properly.
This was used to advantage in some games to create a rough-looking
texture.
> Of course ZX80 characters did not, in general, have properties, but
> line breaking algorithms looked for character 0x00, not character
> 0x80, and so graphic-space behaved like a non-space, not like a space.
I'm sure they existed, but I can't remember anything sophisticated
enough to be called a "line breaking algorithm" in the ZX8* environment.
-Doug Ewell
Fullerton, California
http://users.adelphia.net/~dewell/
This archive was generated by hypermail 2.1.5 : Fri Apr 02 2004 - 14:14:38 EST