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RetroBIOS

Handy

Handy emulates Atari Lynx. It reads 2 files, none of them required: it starts games without them.

About this profile
Detail Value
Type libretro
Classification Community fork
Source https://github.com/libretro/libretro-handy
Upstream https://handy.sourceforge.net/
Version 0.97, stated in libretro/handy.h
Revision libretro/libretro-handy@bc55d462f0b2
Profiled 2026-03-23
Profile YAML, JSON
Cores handy
Systems Atari Lynx
Install this emulator's files

The installer finds your setup and its BIOS folder, then downloads only the files this emulator reads there and checks each one.

Open the Start menu. Type PowerShell and open it. Paste the line. Press Enter.

PowerShell
&([scriptblock]::Create((irm https://abdess.github.io/retrobios/i.ps1))) --emulator handy
Technical notes

Handy is an Atari Lynx emulator by K. Wilkins (Handy 0.95, 2007). The core loads lynxboot.img from the system directory and validates it by CRC32 (0x0D973C9D). If the file is missing or the CRC does not match, the core falls back to an internal HLE BIOS that replicates the boot sequence in software (ram clear, cart loader decrypt, jump to $0200).

The HLE path intercepts CPU calls to ROM addresses FE00, FE19, FE4A and FF80 via a Mikie register write trap (address 0xFD97). When useEmu is true (no valid BIOS loaded), CRom initialises mRomData with a default fill byte (0x88) plus reset vectors pointing to the HLE entry points.

Upstream Handy 0.95 requires the BIOS (throws CLynxException) and validates by checking the first 16 bytes against a hardcoded signature. The libretro port added the HLE fallback and switched to full CRC32 validation.

For headerless cartridges (no LNX/BS93 header), the core loads howard.o from the system directory. This is the Epyx development kit bootloader used to bootstrap raw/headerless ROMs into memory. Upstream requires howard.o for headerless carts (throws exception); the libretro port makes it optional (logs error, continues).

Files

Section titled “Files”

2 files: 0 required, 2 optional. 1 has an HLE fallback.

In this collection: 2 in repo and 0 missing.

Optional

Section titled “Optional”

lynxboot.img optional in repo HLE fallback

Atari Lynx boot ROM (Mikie internal 512B ROM)

  • System: Atari Lynx
  • Validated by CRC32 at load time. If invalid or missing, core uses HLE fallback (system.cpp:303-361 HLE_BIOS_* functions, system.cpp:406-428 trap writes).
Hashes, validation and source

howard.o optional in repo

Epyx Howard bootloader for headerless cartridges

  • System: Atari Lynx
  • Loaded only for headerless carts (no LNX/BS93 header). Resolved relative to the BIOS file path (system directory). Passed to CRam for execution. Most commercial games have headers and skip this entirely.
Source

Next steps

Section titled “Next steps”
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Maintained by Abdess on GitHub. Report a problem.

Packs from release v2026.10.10, .

MIT for the tooling and metadata. BIOS and firmware files are third-party system software, preserved for personal backup, archival and interoperability.