CATS Library Tape 9

Date: 1987
Type: Cassette
Platform(s): TS 2068

Volume 9 of the Capital Area Timex Sinclair Users Group (CATS) 2068 software library, devoted to 3D graphics and plotting. Most of it is the work of James Jones: 3D surface plots of mathematical functions drawn with perspective and hidden-line removal, and animations that store several finished screens in memory and page them back with machine code. It also has Andy Centek’s trigonometry program, Everett Pence’s Moving Waves and Jack Dohany’s QRL screen compressor.

Several of the surface plots are slow: they can take a long time to draw before anything moves. The download has a TAP of each program, text listings and screenshots for some of them, and a WAV recording of the tape.

Programs on the Tape

  • COMPLEX7: a 3D surface combining cosine waves and Gaussian bumps, with hidden-line removal (James Jones) (also #64598 Complex 7)
  • Loader: loads three finished screens (complex1 to complex3, 6,912 bytes each) of the Complex 7 surface, so the pictures can be seen without waiting for them to be drawn
  • DROP: plots the ripple surface z=COS (0.1*(x*x+y*y)) as a wire-frame mesh in perspective (James Jones) (also #64603 Drop)
  • droppages: draws several rotated views of the surface into memory with machine code, then plays them back as an animation; a 30,000-byte code block holds the stored views (James Jones) (also #64600 Droppages)
  • exp: plots Gaussian bell-shaped surfaces in perspective and stores several frames for playback with machine code (also #64605 EXP)
  • FLASH and 1 (Triggraph): two copies of Andy Centek’s “2068 graphics and trig”, which draws labelled quadrant diagrams, curves and Lissajous figures from the SIN and COS multipliers you enter (Andy Centek) (also #55580 2068 Graphics and Trig)
  • movingwave: an animated wave plot driven by SIN, with an ON ERR trap to keep it running (Everett Pence) (also #55587 Moving Waves)
  • PYRAMID: a 3D pyramid rotating through 36 pre-computed frames, with hidden lines removed; adapted from the book Microcomputer Graphics (James Jones) (also #55594 Rotating Pyramid)
  • rle: QRL, a run-length compressor for screens with machine code to encode, decode, invert and wipe them, followed on the tape by two sample picture blocks (space and spacefile) (Jack Dohany) (also #53844 QRL)
  • saddle cos: a 3D saddle-shaped surface stored as four screen pages and animated with machine-code block copies (James Jones) (also #64606 Saddle Cosine)
  • Saddle COS 1: a second version of the saddle surface, paging display-file copies in and out of RAM with LDIR (James Jones) (also #64607 Saddle Cosine 1)

Content

2068 Graphics and Trig

Program

An interactive trigonometry explorer draws labeled quadrant diagrams, parametric curves, and Lissajous figures using user-supplied SIN and COS multipliers with custom UDG graphics.

Complex 7

Program

A 3D surface plot combining cosine waves and Gaussian exponential bumps uses hidden-line removal arrays to render a dramatic mathematical landscape — but be prepared to wait.

Drop

Program

A ripple-surface 3D plotter uses perspective projection and trigonometric rotation to render z=cos(0.1·(x²+y²)) as a connected wireframe mesh.

Droppages

Program

A 3-D surface plotter stores multiple rotated views using hand-coded Z80 machine routines, then plays them back as a smooth animation loop.

EXP

Program

A fascinating 3D surface plotter that renders Gaussian bell curves with perspective projection and saves multiple rendered frames using hand-POKEd Z80 machine code.

Moving Waves

Program

A hypnotic animated wave plot uses sine-driven coordinates and an error-trap handler to keep running until something inevitably goes wrong.

QRL

Program

A compact RLE graphics manager with machine code encode, decode, invert, and wipe routines lets you store, load, and manipulate compressed screen images from cassette.

Rotating Pyramid

Program

A 36-frame rotating 3D pyramid with hidden-line removal, perspective projection, and pre-computed animation frames played back from a single large array.

Saddle Cosine

Program

Watch a 3D saddle-shaped surface animate across four stored screen pages, driven by Z80 machine code block-copy routines and perspective projection math.

Saddle Cosine 1

Program

A morphing 3D saddle-cosine surface rendered with perspective projection, using Z80 LDIR machine code to page display-file snapshots in and out of RAM.

Sprite 2

Program

A BASIC loader installs a self-verifying machine code sprite engine that hooks the interrupt vector, animating graphics automatically while humorous fake copyright strings scroll by.

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Catalog of contents of CATS library tapes. Volume 8 Volume 9

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Note: Type-in program listings on this website use ZMAKEBAS notation for graphics characters.

Tags

Capital Area Timex Sinclair Users Group Downloadable TS 2068 Collection