FlashROM99 is a modern solid-state cartridge for the Texas Instruments TI-99/4A computer that lets you load and run multiple ROM-based programs from a single device. It uses removable storage (typically an SD card) to hold cartridge images and presents them through a simple menu. This allows users to switch between games, utilities, and homebrew software instantly without swapping physical cartridges. It’s widely used in the TI-99 community for development, testing, and convenient access to large software libraries.

Technical Features

• Uses a microcontroller-based design with bank-switched ROM support up to 32 KB.
• Loads cartridge images from a FAT-formatted SD card.
• Presents files through a simple on-screen menu on the TI-99/4A.
• Very fast loading; no GROM emulation (which keeps the design simple and inexpensive).
• Compatible with both NTSC and PAL TI-99/4A systems.
• Supports multiple image files on the card; filenames determine menu entries.

Supported ROM types

• 8 KB ROM cartridges
• 16 KB ROM cartridges
• Up to 32 KB bank-switched ROM cartridges (ROM-only, no GROM)

Not supported

• GROM-based cartridges (any software requiring TI GROMs must use a FinalGROM99 instead)
• Cartridges larger than 32 KB or requiring custom hardware logic

Available as option an SD card filled with 159 Ti99/4A ready-to-run ROMs.