RetroCode v1.4.0 — Assembly, BASIC & 25 Languages with AI

Features

Three Modes, One IDE

Assembly, BASIC, and Code — switch between them with a click. Each mode has its own file tabs, editor, reference panels, and terminal.

Code Editor

Syntax highlighting for 26 languages. Multiple file tabs, find/replace, autocomplete, bracket matching, go-to-line, comment toggle, and word wrap. Run, debug, and build from the embedded terminal.

Assembly Mode

A simple 8-bit CPU with 36 instructions. Two registers (A, B), 256 bytes of memory, zero and carry flags, stack, and a 64x48 pixel graphics display. Step-through debugger included.

BASIC Mode

A TRS-80-style BASIC interpreter with 40+ commands. Line numbers, green-screen terminal, INKEY$ for real-time games, and bitmap graphics with PLOT, DRAW, CIRCLE.

AI Dashboard

Connect to Claude (via MCP), Ollama (local AI), or GitHub Copilot through MorselHub. AI can write code, run programs, manage files, and control the editor via 23 MCP tools.

Multiple Terminals

Up to 4 concurrent terminal sessions with tab switching. Built-in xterm.js with shell selection, available in all three modes.

51 Lessons & 50+ Samples

26 assembly lessons and 25 BASIC lessons. Start from "What is a CPU?" and build up to games and graphics. Over 50 runnable sample programs included.

Per-Mode File Tabs

Up to 5 file tabs in each mode. Independent content, session recovery across crashes and reboots, and full keyboard shortcuts.

6 Themes

Default (green terminal), Standard, Dark, Light, RPG, and High Contrast. Choose your aesthetic or match your accessibility needs.

Screenshots

See It in Action

A visual tour of RetroCode's three modes, AI integration, and retro-inspired interface.

Welcome

Assembly Mode

Assembly graphics output on 64x48 display

64x48 Graphics Output

Built-In Reference

Assembly program running with register view

Running Assembly Code

26 Assembly Lessons

BASIC Mode

RetroCode BASIC terminal with green screen

BASIC Graphics

BASIC Reference

BASIC Editor

35 BASIC Samples

Code Editor

26 Languages

Embedded Terminal

File Tabs

File Browser

AI & MCP Integration

MCP Tools Panel

AI-Assisted Coding

BASIC graphics drawn by AI via MorselHub

BASIC Frog via iMessage

AI + Assembly

Themes & Settings

Default (Green Terminal)

Dark

Light

RPG

High Contrast

Settings

Language Support

26 Languages

Run, debug, and build in 26 languages. Each has syntax highlighting, file detection, and integrated terminal execution.

R Run

D Debug

B Build

Assembly (8-bit)RD

BASIC V2.0R

PythonRD

JavaScriptR

TypeScriptR

CRDB

C++RDB

JavaRB

RustRB

GoRB

SwiftRB

KotlinRB

RubyR

PHPR

PerlR

LuaR

RR

Shell (Bash)R

PowerShellR

HTMLR

CSS

SQL

JSON

YAML

Markdown

Plain Text

AI Integration

AI via MorselHub Experimental

MorselHub is your universal AI broker. Connect to Claude, Ollama, or GitHub Copilot. AI can write code, run programs, and control RetroCode through 23 auto-discovered MCP tools.

Claude (via MCP)

Uses your Claude Max/Pro subscription through Claude Code CLI.

In RetroCode: Code → MCP tab → Install
claude mcp add retrocode node ~/mcp-server.js
Type /retrocode in Claude Code

Ollama (Local AI)

Run AI locally — no internet, no API keys, no token charges.

Install from ollama.com
ollama pull qwen3-vl:4b
Select Ollama in MorselHub AI settings

GitHub Copilot

Use your existing GitHub Copilot subscription for AI assistance.

Authenticate with GitHub in MorselHub
Select Copilot as the AI provider
Chat from RetroCode or MorselHub dashboard

Quick Actions

Chat

Talk through the RetroCode chat panel. AI responds in real time.

Write Code

AI writes directly in your editor with syntax highlighting.

Run Scripts

Execute programs in the terminal. Run assembly, BASIC, or any language.

Save & Read Files

Create, save, and manage project files via chat.

Read Your Code

AI reads what you've written and suggests improvements.

Switch Modes

Move between Assembly, BASIC, and Code. Manage tabs and files.

23 MCP Tools

Category	Tools
Editor	get_editor, set_editor, append_editor
Files	save_file, read_file
Tabs	list_tabs, switch_tab, new_tab
Terminal	open_terminal, close_terminal, terminal, terminal_output
Chat	chat, get_chat, heartbeat
Control	run, stop, switch_mode, get_mode
Reference	asm_reference, basic_reference
System	health, list_languages

Works with MorselHub

Connect RetroCode to MorselHub and chat with Claude from iMessage, webhooks, and more. Your coding sessions flow through MorselHub to your preferred AI provider.

Download MorselHub Learn More

Reference

Assembly Instruction Set

The CPU has 36 instructions organized into 7 categories. All values are 8-bit (0x00 to 0xFF). Two registers (A, B), 256 bytes of memory, zero and carry flags.

Hex	Mnemonic	Description
Data Movement
00	NOP	No operation
01	LDA addr	Load A from memory address
02	LDI val	Load immediate value into A
03	STA addr	Store A to memory address
04	LDB addr	Load B from memory address
05	LBI val	Load immediate value into B
06	STB addr	Store B to memory address
07	MOV	Copy A to B
Arithmetic & Stack
10	ADD	A = A + B
11	SUB	A = A - B
12	INC	A = A + 1
13	DEC	A = A - 1
14	ADI val	A = A + immediate
15	MUL	A = A * B
16	DIV	A = A / B
17	MOD	A = A % B
18	PUSH	Push A onto stack
19	POP	Pop stack into A
Logic
20	AND	A = A AND B
21	OR	A = A OR B
22	XOR	A = A XOR B
23	NOT	A = NOT A
24	SHL	Shift A left
25	SHR	Shift A right
26	CPI val	Compare A with immediate
Compare & Branch
30	CMP	Compare A with B
31	JMP addr	Jump to address
32	JZ addr	Jump if zero flag set
33	JNZ addr	Jump if zero flag clear
34	JC addr	Jump if carry flag set
I/O & Graphics
40	OUT	Output A to display
41	INP	Input to A
50	PLT	Plot pixel at (A, B)
51	UPL	Unplot pixel at (A, B)
52	CLG	Clear graphics
FF	HLT	Halt

BASIC V2.0 Reference

A complete BASIC interpreter with 40+ commands, math and string functions, graphics, game input, and a virtual file system.

PRINT "HELLO WORLD"
LET A = 5
FOR I = 1 TO 10
PRINT I; " x "; A; " = "; I * A
NEXT I
PRINT ""
PRINT "DONE!"
END

Commands

PRINT, INPUT, LET, GOTO, IF/THEN, FOR/NEXT/STEP, GOSUB/RETURN, REM, END, CLS, DIM, DATA/READ/RESTORE, ON GOTO/GOSUB, STOP/CONT, POKE/PEEK

Math Functions

INT, RND, ABS, SQR, SGN, SIN, COS, TAN, LOG, EXP

String Functions

LEN, LEFT$, RIGHT$, MID$, CHR$, ASC, TAB, VAL, STR$

Game Input

INKEY$ — non-blocking key detection for real-time games. Supports arrow keys, WASD, SPACE, ENTER, ESC, and all printable characters. Game loops run at ~60fps.

Graphics (64x48 bitmap)

PLOT, UNPLOT, DRAW, CIRCLE, BOX, FILL, GCLS, COLOR, LOCATE

Virtual Files

SAVE$, LOAD$, DIR, DEL — persistent storage in the browser

Download

Get RetroCode v1.4.0

Free to download and use. No account required. No internet required after download.

macOS

macOS 12+ · Apple Silicon (arm64)

Download .dmg

Windows

Windows 11+ · x64

Download .zip

Also Available

MorselHub for macOS — AI broker for Claude, Ollama, and Copilot. Adds iMessage and webhook integration.

Reference

Keyboard Shortcuts

Shortcuts for macOS. On Windows, replace Cmd with Ctrl.

Editor

Run codeCmd + R

Stop executionCmd + .

Save fileCmd + S

Open fileCmd + O

New fileCmd + N

Find / ReplaceCmd + F

Go to lineCmd + G

Toggle commentCmd + /

IndentTab

OutdentShift + Tab

Application

Toggle terminalCmd + T

Toggle chatCmd + Shift + C

Toggle referenceCmd + Shift + R

Toggle file browserCmd + Shift + F

SettingsCmd + ,

Zoom inCmd + =

Zoom outCmd + -

Reset zoomCmd + 0

Tabs

Tab 1-5Cmd + 1 ... Cmd + 5

Next tabCtrl + Tab

Previous tabCtrl + Shift + Tab

Close tabCmd + W

Assembly Mode

StepCmd + Shift + S

Reset CPUCmd + Shift + X

AssembleCmd + B

Documentation

Learn More

Full documentation is available in the app (Learn tab + Reference panels) and online.