palega — EGA Palette Swapper TSR for DOS

palega is a small DOS TSR (Terminate and Stay Resident) that intercepts EGA palette BIOS calls
(INT 10h, AH=10h, AL=02h) and replaces the game’s palette with a custom one.

This allows you to recolor classic EGA games in real time — without modifying the game files — simply by loading a TSR before launching the game.

palega works on:

• DOSBox-X (tested)
• 86Box (tested)
• FreeDOS (tested)
• Real MS-DOS hardware
• Any emulator that performs true BIOS INT 10h palette calls

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Features

• Hooks INT 10h EGA palette writes
• Replaces the game’s palette with a custom .pal file
• Works with many real‑mode EGA games
• TSR stays resident and applies palette changes automatically
• Very small memory footprint
• Compatible with DOSBox‑X, 86Box, FreeDOS, and real MS‑DOS

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Screenshots

Commander Keen 1 — Original vs Palega

Original	Palega

Palette used: keen.pal

Might & Magic II — Original vs Palega

Original	Palega

Palette used: mm2.pal

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How It Works

EGA games typically set their palette using BIOS interrupt:

INT 10h
AH=10h (palette functions)
AL=02h (set all palette registers)

palega hooks this interrupt and substitutes your custom palette whenever a game attempts to load its own. Note: Not all EGA games do this, see game_list.txt for a compability list of games confirmed to work with palega.

Palette File Format (.pal)

palega uses a simple binary palette format designed for EGA hardware.
Each .pal file is exactly 17 bytes:

• Bytes 0–15 — EGA palette registers (16 colors)
• Byte 16 — Border (overscan) color

There is no header or metadata — just raw palette values.

Byte Layout

Offset  Size  Description

0x00    1     Palette color 0
0x01    1     Palette color 1
...
0x0F    1     Palette color 15
0x10    1     Border color

Value Range

Each byte is a 6‑bit EGA color value in the range:

00h–3Fh  (0–63 decimal)

Bit layout:

• Bits 0–1 → Red (0–3)
• Bits 2–3 → Green (0–3)
• Bits 4–5 → Blue (0–3)

Example .pal File (Hex Dump)

00 02 05 07 08 0A 0C 0F
10 12 15 17 18 1A 1C 1F
00

This represents:

• 16 palette entries
• Border color = 00h
• Total size = 17 bytes

Using Custom Palettes

You can test palega easily using Commander Keen 1 Shareware, which is freely available and legal to redistribute.

Example:

C:\GAMES\KEEN> PALEGA.EXE KEEN.PAL
C:\GAMES\KEEN> KEEN1.EXE

Palette File Location

If you provide a filename without a path, palega searches:

1. Current working directory
2. pal/ subdirectory (relative to the working directory)
3. Will automatically append .pal filename.