BBC Micro Performance Wiki

The New Advanced User Guide (NAUG)

4 min read

The New Advanced User Guide

Comprehensive technical reference for the BBC Master, Master Compact, Model B, B+, and Electron. Successor / expansion of the original Acorn Advanced User Guide. Covers the full hardware stack (6502/65C12, memory map, video, VIAs, 1MHz bus, Tube, ADC, sound) and the Machine Operating System (MOS) — including the complete OSBYTE and OSWORD call tables.

This is the foundational reference for the wiki. Most hardware-detail and MOS-call claims elsewhere should cite a specific chapter and page here.

Citation convention

Cite as [[sources/naug]] §<chapter>.<section> p<page> — e.g. [[sources/naug]] §13.3.5 p199 for “Vertical Timing”.

When a chapter is fully ingested, this page links to the per-chapter source stub (e.g. naug-ch13-video), and detailed claims should cite the chapter stub directly.

Chapter index

Status legend: [ ] not yet ingested · [~] partial · [x] ingested

  • [ ] Ch1 New to machine code — p10
  • [x] Ch2 BASIC Assembler — p13 (OPT, P%, labels, EQU, BRK, CALL/USR, macros, user zero page) → naug-ch02-basic-assembler
  • [x] Ch3 Machine Code Arithmetic — p22 (2’s complement, BCD, 65C12 BCD) → naug-ch03-04-arithmetic-addressing
  • [x] Ch4 Addressing Modes — p26 (all NMOS modes + 65C12 additions) → naug-ch03-04-arithmetic-addressing
  • [x] Ch5 6502 Instruction Set — p35 (full mnemonic reference, ~70 pages) → naug-ch05-6502-isa
  • [x] Ch6 OS Introduction — p107 (OSWRCH, OSRDCH, OSBYTE, OSWORD, OSCLI, OS memory page 0, page 2) → naug-ch06-os-introduction
  • [x] Ch7 Events — p126 (EVNTV, enable/disable, OSEVEN) → naug-ch07-events
  • [x] Ch8 Interrupts — p131 (NMI, IRQ, OS handler, System/User VIA, Electron ULA, BRK) → naug-ch08-interrupts
  • [x] Ch9 Buffers — p143 (INSV, REMV, CNPV, buffer operations) → naug-ch09-buffers
  • [x] Ch10 Escape — p154 → naug-ch10-escape
  • [x] Ch11 Hardware — p157 → naug-ch11-hardware
  • [x] Ch12 Memory — p162 (overview, paged ROM/RAM, shadow RAM, Master access control) → naug-ch12-memory
  • [x] Ch13 Video/Graphics — p172 (VDU, 6845 CRTC, horizontal/vertical timing, scrolling, fast animation, Video ULA, palette, screen memory maps) → naug-ch13-video
  • [x] Ch14 Keyboard — p225 → naug-ch14-keyboard
  • [x] Ch15 Serial I/O — p240 (RS232C, Acorn RS423, 6850, Serial ULA, CFS) → naug-ch15-serial
  • [x] Ch16 Filing Systems — p257 (OSFILE/OSARGS/OSBGET/OSBPUT/OSGBPB/OSFIND, FSCV, CFS, RFS, DFS, ADFS, NFS, 1770 FDC) → naug-ch16-filing
  • [x] Ch17 Paged ROMs — p290 (ROM header, service calls, installation per machine, language ROMs, *ROM, OS routines, 100Hz polling) → naug-ch17-paged-roms
  • [x] Ch18 2nd Processor / Tube — p334 (32-bit addressing, Tube ULA, 6502/Z80/32016 second processors) → naug-ch18-tube
  • [x] Ch19 Clocks, Timers, CMOS — p359 (system clock, timers, CMOS RTC, CMOS RAM) → naug-ch19-clocks-cmos
  • [x] Ch20 ADC system — p372 → naug-ch20-adc
  • [x] Ch21 Sound / Speech — p379 (76489 sound chip, speech chip) → naug-ch21-sound
  • [x] Ch22 VIAs — p387 (User/Printer VIA, System VIA, ports, handshaking, timers T1/T2, shift register, interrupts) → naug-ch22-vias
  • [x] Ch23 1MHz Bus & Cartridges — p409 (FRED &FC, JIM &FD, bus signals, timing, 128K EPROM cartridges) → naug-ch23-1mhz-bus
  • [x] Ch24 Miscellaneous — p426 (BREAK/reset, printer, *CODE/*LINE, NETV, KEYV) → naug-ch24-misc
  • [ ] Glossary — p439
  • [ ] Bibliography — p442
  • [x] Appendix A — OSBYTE Calls — p443 → osbyte (directory; detail backfilled per-chapter)
  • [x] Appendix B — OSWORD Calls — p448 → osword (directory; detail backfilled per-chapter)
  • [ ] Index — p449

Ingest plan

Chapter-by-chapter, on demand. When you say “ingest naug ch13”, the workflow is:

  1. Read the chapter in full.
  2. Create wiki/sources/naug-ch<N>-<slug>.md with section-level summary and key extracts.
  3. Create/update the affected entity, concept, and technique pages across the wiki, with [[sources/naug-ch-]] citations.
  4. Update the checkbox above, update wiki/index.md, append to wiki/log.md.

Appendices A and B will be done as full-table extractions into wiki/os/osbyte.md and wiki/os/osword.md.

Notes on machine coverage

NAUG covers five machines that differ in important ways. When extracting claims, always note which machine(s) a claim applies to. Common variants:

  • NMOS 6502 (Model B, B+, Electron) vs 65C12 / 65SC12 (Master, Master Compact) — additional addressing modes and instructions (see Ch3.3, Ch4.12).
  • Memory map differs across B / B+ / Master (shadow RAM, sideways RAM, ANDY/HAZEL regions on Master) — see Ch12.
  • Video ULA (Model B / B+ / Master) vs Electron ULA (combined video + sound + cassette + keyboard).
  • Sound: 76489 on BBC models; Electron uses its own ULA.
  • Tube: not present on Electron.

When a wiki page describes a feature, prefer to state machine applicability up front.

This wiki is curated by Claude following the LLM-Wiki methodology — a human curates source documents, the LLM compiles structured cross-linked markdown. Content may contain errors, omissions, or stale claims. For authoritative information refer to the original source documents in the bbc-documents GitHub archive.

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