nd100uc - ND-100/110/120 Microcode Toolchain

A complete toolchain for working with microcode from the Norsk Data ND-100, ND-110, and ND-120 minicomputers. Web-based disassembler/viewer, ROM combiners, and build pipeline.

The TypeScript library and YAML definitions live in the shared nd-microcode-meta submodule. The VSCode extension lives in a separate repo.

Live web viewer: hackercorplabs.github.io/nd100uc

Status

Component	Status	Notes
YAML canonical definitions	done	299 ND-100, 357 ND-110, 358 ND-120 tokens, all field positions
TypeScript disassembler	done	3-line assembly format for all three models
TypeScript assembler	done	100% bit-exact roundtrip on all tested ROMs
Round-trip (disasm -> reasm)	done	100% bit-exact on all five ROM images (see Validation)
ND-100 PROM combiner	done	16-chip 82S185 interleave + decode-PLA (Python)
ND-110/120 ROM combiner + CLI	done	2-chip EPROM interleave with auto-detect (TypeScript)
Web disassembler	done	3-line layout, opcode badges, clickable labels, all models
GitHub Pages auto-deploy	done	Pushes to main auto-deploy the web viewer
VSCode extension	done	vs-extension-nd110-uc

Repository layout

Path	Description
external/meta/	Submodule: nd-microcode-meta
external/meta/defs/	YAML token/field definitions (source of truth)
external/meta/lib/ts/	TypeScript library (@nd100uc/microcode)
external/meta/reference/roms/	PROM/EPROM dumps for all three models
external/meta/tools/nd100-combine.py	ND-100 multi-PROM combiner (Python)
src/index.html	Web app source
tools/web-build/build-web.mjs	Web build: combine ROMs, generate symbols, bundle JS
tools/web-build/generate-nd100-symbols.mjs	Generate ND-100 labels from decode-PLA
tools/rom-combiner/	nd100uc-rom CLI for ND-110/120 EPROM combine/split
microcode/	ND-110 RASK assembled source + binary
.github/workflows/deploy-web.yml	GitHub Pages auto-deploy on push to main

Supported models

Model	Word size	Chips	XOR on load
ND-100	64-bit	16 x 82S185 PROMs per bank	0x0F800000 (bits 23-27)
ND-110	64-bit	2 x 27256 EPROMs	0x0FC00000 (bits 22-27)
ND-120	64-bit	2 x 27C256 EPROMs	None (canonical form)

All three models use 64-bit microinstruction words.

Hardware

ND-100	ND-110	ND-120

Building the web app

git clone --recurse-submodules https://github.com/HackerCorpLabs/nd100uc.git
cd nd100uc

# Build the TS library (in the submodule)
cd external/meta/lib/ts && npm ci && npm run build && cd ../../../..

# Build the web app
node tools/web-build/build-web.mjs

# Serve locally
cd web && python3 -m http.server 8765

The web app is also auto-deployed to GitHub Pages on every push to main.

Web viewer features

• 3-line assembly layout (Line 1: registers+ALU, Line 2: IDB+COMM+sequencing, Line 3: branch/condition)
• All three models: ND-100, ND-110, ND-120
• Syntax-highlighted tokens with hover tooltips from YAML descriptions
• Clickable branch targets and labels for navigation
• Opcode badges showing which macro-instructions dispatch to each microaddress (ND-100)
• Alternating row backgrounds to visually separate instructions

Available ROM images

Entry	Model	Records	Source
ND-110 RASK (K)	ND-110	4865	Assembled from user-maintained source
ND-110 3095-L factory	ND-110	6879	Combined from 37948L + 37949L EPROMs
ND-120 3202D 4MB	ND-120	8192	Combined from 45132L + 45133L EPROMs
ND-120 3202D 6MB	ND-120	8192	Combined from Frode's 6MB variant EPROMs
ND-100 3033S	ND-100	2048	Combined from 16 82S185 PROMs
ND-100 3033E-CX base	ND-100	2008	Combined from 16 82S185 PROMs
ND-100 3033E-CX ext	ND-100	1529	Combined from 16 82S185 PROMs (uaddr 0o4000+)

Validation

ROM	Model	Records	Roundtrip
ND-110 RASK (assembled)	ND-110	4865	100% bit-exact
ND-110 3095-L (factory)	ND-110	6879	100% bit-exact
ND-120 3202D 4MB (factory)	ND-120	8192	100% bit-exact
ND-100 3033S (factory)	ND-100	2048	100% bit-exact
ND-100 3033E-CX (factory)	ND-100	2008	100% bit-exact

Related repos

Repo	Description
nd-microcode-meta	Shared submodule: YAML definitions, TS library, reference ROMs
vs-extension-nd110-uc	VSCode extension for .uc files

License

MIT - see LICENSE.