An assembler IDE for 8-bit home computers (currently KC85/3, KC85/4, C64 and Amstrad CPC) with integrated assembler and debugger.

Screenshots

Quickstart

• clone https://github.com/floooh/kcide-sample
• open VSCode in one of the following subdirectories:
  • kc854/: for the KC85/4 sample
  • c64/: for the C64 sample
  • cpc/: for the Amstrad CPC sample
• the extension should detect the kcide.project.json file and activate itself (a new tab should open with the embedded emulator)
• open the src/main.asm file, and hit F7, you should see a message Output written to ..., and a new subdirectory build/ should have been created with the files out.hex, out.lst and out.map, and a system-specific binary file (out.kcc, out.prg or out.bin)
• with the src/main file loaded and active, press F5 to start a debug session
• explore additional features by opening the VSCode command palette and typing kcide

Feature Overview

• build the project into a KCC or PRG file by pressing F7
• build and debug the project by pressing F5
• explore additional commands in the command palette by typing kcide
• the assembler is a slightly extended ASMX compiled to WASI, the changes are tracked here
• the emulators are taken from the chips project compiled to WASM+WebGL, running in a VSCode tab
• original syntax highlighting https://github.com/mborik/z80-macroasm-vscode/blob/main/syntaxes/z80-macroasm.tmLanguage.json, extended for 6502 assembler syntax and special ASMX keywords
• during a debug session, you can change into the 'raw' disassembly view at any time by running the palette command Open Disassembly View, this also happens automatically when stepping into code that's not part of the project (such as operating system code)
• you can inspect memory by hovering over a CPU register in the VSCode Variables panel and clicking the 'binary' icon with the tooltip View Binary Data, however note that the emulator's integrated debugging UI has a much more powerful memory viewer and editor than what VSCode can provide through the Debug Adapter Protocol

Starting a new KC85 project

• create a new project directory and cd into it

• create a file project.kcide.json looking like this, tweak the attributes as needed (the extension provides a JSON schema to VSCode to provide completion and validation):

  {
    "emulator": {
        "system": "KC85/4"
    },
    "assembler": {
        "srcDir": "src",
        "mainSourceFile": "main.asm",
        "cpu": "Z80",
        "outDir": "build",
        "outBaseFilename": "hello",
        "outFiletype": "KCC"
    }
  }

• ...also put the outDir value into your .gitignore

• create a directory src/ and in it a file main.asm execution will start at the label _start:

      org 200h
  _start:
      ld a,5
      ld b,6
      add a,b
      ret

• test building by pressing F7 or running the palette command KCIDE: Build

• test debugging by pressing F5 or running the palette command KCIDE: Debug

Starting a new C64 project

• create a new project directory and cd into it

• create a file project.kcide.json looking like this, tweak the attributes as needed (the extension provides a JSON schema to VSCode to provide completion and validation):

  {
      "emulator": {
          "system": "C64"
      },
      "assembler": {
          "cpu": "6502",
          "srcDir": "src",
          "mainSourceFile": "main.asm",
          "outDir": "build",
          "outBaseFilename": "out",
          "outFiletype": "PRG"
      }
  }

• ...also put the outDir value into your .gitignore

• create a directory src/ and in it a file main.asm execution will start at the label _start

        org $801
  _start:
        lda #5
        clc
        adc #6
        rts

• test building by pressing F7 or running the palette command KCIDE: Build

• test debugging by pressing F5 or running the palette command KCIDE: Debug

• for a more 'idiomatic' C64 PRG sample, check the example project here: https://github.com/floooh/kcide-sample/tree/main/c64

Starting a new Amstrad CPC project

• create a new project directory and cd into it

• create a file project.kcide.json looking like this, tweak the attributes as needed (the extension provides a JSON schema to VSCode to provide completion and validation):

  {
      "emulator": {
          "system": "CPC6128"
      },
      "assembler": {
          "cpu": "Z80",
          "srcDir": "src",
          "mainSourceFile": "main.asm",
          "outDir": "build",
          "outBaseFilename": "out",
          "outFiletype": "AMSDOS_BIN"
      }
  }

• ...also put the outDir value into your .gitignore

• create a directory src/ and in it a file main.asm execution will start at the label _start

      org 4000h
  _start:
      ld a,5
      ld b,6
      add a,b
      ret

• test building by pressing F7 or running the palette command KCIDE: Build

• test debugging by pressing F5 or running the palette command KCIDE: Debug

• for a more 'idiomatic' C64 PRG sample, check the example project here: https://github.com/floooh/kcide-sample/tree/main/c64

The integrated debugging UI

The emulator comes with an integrated debugging UI implemented with Dear ImGui which is much more powerful than what the VSCode debug adapter protocol can provide:

• the integrated CPU debugger allows to step in single clock cycles instead of full instructions and displays the actual cycle count of executed instructions
• more powerful breakpoints:
  • break on memory access
  • break on IO access
  • break on interrupts
  • break on specific raster scanlines (C64 only)
• a much more powerful memory view/edit window
• an execution history window
• status windows for the CPU and system chips
• ...and more

Running in VSCode for Web

The extension has 'best effort' support for running in the VSCode browser version with the following known issues:

• currently only the Insider version is supported (https://insiders.vscode.dev/)
• currently only working on local repositories is supported, directly opening Github respositories doesn't work
• starting a debug session for the first time seems to take considerably longer than on the desktop VSCode version