The Coleco ADAM Dual BIOS Mod Kit by Arcade Collecting is a hardware enhancement engineered to upgrade the startup behavior of the Coleco ADAM memory console. It allows users to toggle between multiple system boot behaviors to bypass some of the machine's most repetitive factory delays.
The Purpose of a Dual BIOS:
When a standard, unmodified Coleco ADAM home computer is switched on, its factory Elementary Operating System (EOS) forces the console into a strict, predefined initialization path:
- The SmartWriter Lockout: Upon boot-up, the system automatically redirects the user straight into the native SmartWriter Word Processor environment. If the user wants to play a game cartridge or run a software program from a third-party disk or tape drive instead, they are forced to wait out an automatic delay loop and manually trigger a reset to break out of the typing mode.
- The 12-Second Title Screen: When playing classic ColecoVision cartridges on the ADAM architecture, the stock BIOS enforces an unskippable 12-second title copyright splash screen before loading the game select menu.
The Arcade Collecting Modification
The Arcade Collecting kit resolves this bottleneck by substituting the factory 24-pin ROM chip with an integrated circuit containing multiple system behaviors:
- The EPROM Upgrade: Because original Coleco PROMs cannot be rewritten, the kit supplies a high-capacity 28-pin EPROM chip (such as a 27128 or 27C256). The bottom half of the chip storage is flashed with the standard, authentic stock ADAM/ColecoVision BIOS for perfect software compatibility. The upper storage layer is flashed with a modified "Intro-Skip" or "No-Title-Delay" BIOS image.
- Instant Cartridge Booting: The customized secondary BIOS circumvents the SmartWriter startup block. If a game cartridge is detected in the slot, it immediately loads the software menu without forcing the user to witness the mandatory copyright pause screens or typewriter environment.
- The Logic Hack: Because the original motherboard routing is hardwired for 24-pin chips, installing the 28-pin alternative requires fine soldering. Installers have to carefully sever two traces on the underside of the PCB and solder two jumper wire configurations to route address line inputs safely to the new pin layout
