Appendix J
Glossary
Terms this book uses without stopping to explain them.
The Machine#
Bitmap mode — a display mode addressing individual pixels rather than characters. Costs far more memory traffic per frame than a character mode, and buys detail no arrangement of characters can reach.
C64U — the Commodore 64 Ultimate, and the name this book uses for the whole Ultimate platform: the C64U itself, the earlier Ultimate 64 and Ultimate 64 Elite boards, and — with the exceptions noted where they matter — the Ultimate II+ cartridge. They function the same way and speak the same protocols, which is why one name covers them. u64:// is the connection scheme for all of them, named after the board the scheme was written against.
Character mode — a display mode drawing the screen from the 8×8 glyphs in the character ROM, one byte per cell. Cheap, and the only place text overlays can put text without help.
Character ROM — the Commodore's own glyph shapes. c64cast reads them off your machine on the first run so that a preview window renders in the same face the Commodore will.
DMA — direct memory access. The route c64cast writes to the Commodore's memory by, over a socket rather than the REST interface, because REST cannot carry writes at a useful rate.
REU — the RAM Expansion Unit. Additional memory the Ultimate can emulate, used here as a buffer deep enough to keep audio fed.
SID — the sound chip, and by extension a tune file written for it. Two models exist, 6581 and 8580, and they do not sound alike.
TeensyROM+ — the other supported backend, a cartridge reached over USB serial or over the network. A narrower pipe than the C64U's, and the features that depend on the wider one say so.
VIC-II — the video chip. Everything in the display pipeline exists to end as values in its registers.
The Software#
Backend — the hardware c64cast is driving, and the transport it drives it over. Selected by the scheme of a connection target.
Display mode — how a frame is turned into something the VIC-II can show. Six of them; see Appendix D for what each will accept.
Effect — a transformation applied to a frame after its source has drawn it and before the display mode quantizes it. Several may be chained.
Ensemble — several Commodores driven from one run, each with its own configuration, gathered by a master file.
Extra — an optional group of Python dependencies, named in square brackets after the package: c64cast[video]. Each one unlocks a feature that would otherwise log a line and be skipped. They do not accumulate, so installing one by name removes the others; c64cast[all] is the install that has everything.
Generator — a procedural frame source: a scene that computes its picture rather than reading one.
Live parameter — a parameter that can be moved while a show is running, from a knob, a pad, or the console. Appendix F lists them all.
Machine settings — the per-computer overlay at ~/.config/c64cast/settings.toml, holding what this machine should assume when nothing else says.
Overlay — something drawn over a scene rather than instead of it: a clock, a logo, a spectrum.
Quick playback — naming media on the command line instead of writing a configuration. Builds one in memory and runs it.
Scene — one item in a playlist: a source, a display mode, whatever overlays it carries, and how long it lasts.
Target — the string naming a live parameter in a param mapping, as effect.decay. Appendix F is the list.