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Overview

DevCPC supports C compilation using SDCC (Small Device C Compiler), allowing you to write game logic in C while leveraging the 8BP library or direct firmware calls.

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Requirements

1

Install SDCC

Install SDCC for your platform:
brew install sdcc
Verify installation:
sdcc --version
2

Configure C settings

Add C configuration to devcpc.conf:
# C code compilation
C_PATH="C"
C_SOURCE="main.c"
C_CODE_LOC=20000
C code must load below address 23999 to avoid overwriting the 8BP library.

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Configuration Options

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C_PATH
string
Directory containing C source files
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C_SOURCE
string
Main C source file to compile (e.g., main.c)
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C_CODE_LOC
number
Memory address where compiled code will be loaded (must be < 23999)

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Memory Limits

The compiled C code must not exceed address 23999 (0x5DBF) to avoid destroying the 8BP library: 
# Safe configuration
C_CODE_LOC=20000  # Loads at 20000
MEMORY 23599      # In BASIC

# For more space, load C code lower
C_CODE_LOC=19000
MEMORY 18999      # In BASIC

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Using 8BP from C

DevCPC includes an 8BP wrapper header for calling 8BP functions from C:
C/main.c
#include "8BP_wrapper/8BP.h"

void main(void) {
    // Clear screen
    _CLS();
    
    // Set ink colors
    _INK(0, 0);   // Background black
    _INK(1, 24);  // Foreground yellow
    
    // Draw text
    _LOCATE(10, 10);
    _PRINT("Hello from C!");
    
    // Wait for key
    while(!_INKEY()) {}
}

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Compilation Process

When you run devcpc build, the C compilation process:
  1. Compiles C source with SDCC targeting Z80
  2. Generates Intel HEX file (.ihx)
  3. Converts HEX to binary with hex2bin
  4. Places binary in obj/ directory
  5. Adds binary to DSK with correct load address
  6. Verifies memory limits (< 23999)

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Loading from BASIC

Load and execute your C code from BASIC: 
10 REM Load 8BP with graphics
20 MEMORY 23599
30 LOAD"8BP0.bin"
40 CALL &6B78
50 REM Load C program
60 LOAD"main.BIN",20000
70 CALL 20000
The CALL address matches your C_CODE_LOC setting.

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Project Structure

my-game/
├── C/
│   ├── main.c              # Your C code
│   ├── 8BP_wrapper/
│   │   └── 8BP.h          # 8BP function declarations
│   └── mini_BASIC/
│       └── minibasic.h    # BASIC-like functions
├── ASM/
│   └── make_all_mygame.asm  # 8BP library
└── devcpc.conf

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Example Project

See C Project Example for a complete working example with C and 8BP integration.

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Troubleshooting

Your compiled code is too large. Solutions:
  • Use a lower C_CODE_LOC value
  • Reduce BASIC MEMORY accordingly
  • Optimize C code (remove unused functions)
  • Compile with -Wl-r flag for position-independent code
Install SDCC:
# macOS
brew install sdcc

# Linux  
sudo apt-get install sdcc
Ensure:
  • 8BP library is loaded first in BASIC
  • CALL &6B78 executed before loading C code
  • Memory limits respected (< 23999)

C Project Example

Complete C project with SDCC and 8BP

8BP Library

Learn about the 8BP game library

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