AZM Book 2 — Programming the TEC-1G

This book is being written now. The chapter pages are publishable stubs: they show the intended path through the TEC-1G, MON-3, Debug80, and the hardware features that make the machine worth programming.

Book 1 taught the Z80 without tying you to one machine. Book 2 makes the machine concrete. It starts with the TEC-1G as a modern rebirth of a 1980s learning-computer idea, then uses MON-3 services and Debug80 before moving down to direct ports and timing-sensitive display work.

The 8x8 RGB matrix is an add-on rather than the core machine, but this book uses it as the main visual target once the basics are in place. It forces useful lessons: scanning, persistence of vision, bit-plane colour, framebuffers, and cooperative timing. Tetro and Pacmo become larger case studies after those ideas are earned.

Learning arc

  1. The TEC-1G reborn — the 1980s learning-computer idea, rebuilt around a Z80 with modern tooling and richer peripherals.
  2. Running under MON-3 — the monitor as the first programming environment: API calls, $4000, keypad, LCD, seven-segment helpers, sound, serial, and GLCD support.
  3. Debug80 workflow — project files, profiles, targets, bundled monitor ROMs, source mapping, breakpoints, registers, memory, and listings.
  4. First program at $4000 — user RAM, entry point, running from MON-3, and proving execution in Debug80.
  5. Keypad input — MON-3 key scanning, raw key codes, new press vs held key, and simple input state.
  6. Text on the LCD — write useful messages through MON-3 first, then understand the HD44780 command/data ports.
  7. Numbers on the six-digit display — segment glyphs, MON-3 conversion helpers, and the idea of scanned numeric output.
  8. Scanning and persistence of vision — why multiplexed displays work and why your program must keep refreshing them.
  9. Direct seven-segment scanning — digit masks, segment bytes, PortDigits, PortSegs, and timing mistakes.
  10. One-bit sound — MON-3 sound helpers, then direct speaker-bit toggling as timed output.
  11. The 8x8 RGB add-on — row scanning, red/green/blue bit planes, row select, and colour.
  12. Framebuffers and colour — compose pixels in RAM, then scan rows out without corrupting the display.
  13. A cooperative runtime — keep keypad, LCD, seven-segment scan, sound, matrix scan, and program logic moving without interrupts.
  14. Shared game architecture — the common Tetro/Pacmo hardware layer: scan tick, framebuffer helpers, LCD, HUD, sound, and include boundaries.
  15. Tetro case study — falling coloured tiles on an 8x8 matrix, with scoring, LCD state, sound cues, and pause/restart flow.
  16. Pacmo case study — a scrolling multicolour maze on an 8x8 viewport, with monsters, consumable paths, score, LCD, and sound.
  17. Beyond the core — GLCD, matrix keyboard, RTC, storage, serial workflows, and expansion topics for later chapters or a future book.

Chapter table

Ch File Status What it covers
— Introduction Stub Why the TEC-1G book sits between fundamentals and algorithms
1 The TEC-1G Reborn Stub History, learning-computer purpose, Z80, MON-3, Debug80
2 Running Under MON-3 Stub Monitor services, RST 10H, API call convention, $4000
3 Debug80 Workflow Stub debug80.json, profiles, targets, bundled ROMs, listings
4 First Program at $4000 Stub User RAM, entry point, visible proof of execution
5 Keypad Input Stub MON-3 API scanning, key constants, edge vs held input
6 Text on the LCD Stub MON-3 LCD calls, HD44780 commands, strings
7 Numbers on the Six-Digit Display Stub Segment glyphs, conversion helpers, scanned output
8 Scanning and Persistence of Vision Stub Multiplexing, timing, display refresh as program work
9 Direct Seven-Segment Scanning Stub PortDigits, PortSegs, masks, scan loops
10 One-Bit Sound Stub MON-3 sound calls, direct speaker-bit toggling
11 The 8x8 RGB Add-On Stub Row scan, colour planes, matrix ports
12 Framebuffers and Colour Stub Back buffers, row layout, drawing cells and rows
13 A Cooperative Runtime Stub Scan tick, logic slices, hardware maintenance
14 Shared Game Architecture Stub Common Tetro/Pacmo hardware layer and boundaries
15 Tetro Case Study Stub Falling-block program structure on the TEC-1G
16 Pacmo Case Study Stub Scrolling maze program structure on the TEC-1G
17 Beyond the Core Stub GLCD, matrix keyboard, RTC, storage, serial, expansion

Sources for this book

The monitor-first chapters will use MON-3 API documentation and Debug80’s TEC-1G platform support. The display and game chapters will use the Tetro repository as source material for real keypad, LCD, seven-segment, sound, framebuffer, and cooperative-loop patterns.

← AZM Books Introduction →

Table of contents