ROMX (Apple II/II+)

ROMX is available for order from ReActiveMicro!

ROMX%20-%20Top ROMX%20-%20Bottom 2316B

(Images shown above are ROMX and the 2316B SPCL text ROM for Apple II/II+ which is preloaded with 16 fonts).

Key Features

  • Replaces existing D0-F8 ROM chips and optionally the text ROM also
  • No slots used - socket safe headers
  • Low profile, small footprint
  • 15 user ROM images + firmware
  • No switches - select a ROM from the menu
  • User programmable - in-system!
  • Firmware upgradeable - in system!
  • Upload a custom ROM in seconds
  • Supports DOS images for instant boot
  • ROM-Link to optional ROMX text ROM
    • Adds lower case character sets (1)
    • Select font from the menu
    • Link a font with a ROM image
  • Supports Apple II Rev 0 - 7
    • ROMX 2513 text ROM available for pre-Rev 7
    • ROMX 2316B text ROM available for Rev 7
  • Works in many clones

Note 1. ROMX Video ROM contains many different fonts that include lower case characters. To enter lower case text however will require you to install the Shift Key Mod

ROMX is an in-system programmable device that replaces the system ROM chips in your Apple II/II+ computer. It will store up to 15 ROM images, and present them for selection via an on-screen menu that is displayed at power up. In addition, the menu system itself (the ROMX firmware) is updateable in-system.

Being in-system programmable means that you can re-program ROMX with your own ROM images without removing the device from your computer, and without need for an external programmer. Uploading of new ROM images is done through either the ROMX menu, or by running the ROMX.DISK utility from the ROMX floppy disk image. The firmware image is also upgradeable using the same process.

ROMX features a ROM-Link interface that connects the ROMX board to an optional ROMX text ROM module. The text ROM contains 16 different fonts, with the ROM-Link interface allowing you to swtich text/video ROMs from the ROMX menu or to associate a font with a specific ROM image. Note that the text/ ROM module is not in-system programmable, however we can share the programming adapter PCB design such that you can reprogram it in an EPROM programmer if you would like to customise the font selection. See the blog post here for the list of available fonts.

ROMX firmware v0.963 onwards supports linking of a ROM image with a DOS image loaded into a ROM slot. When a ROM image is linked to a DOS image, DOS will be loaded the instant the ROM is selected! This can be a real time saver.

ROMX is preloaded with a number of ROM images including basic diagnostics - the as-shipped selection is shown below:

Note that the JTAG header is for production programming of the CPLD only - it's not used to upload ROM images. ROM's are uploaded directly from the computer - BLOAD a 12KB ROM image, run up the menu, and U)PLOAD it to flash memory, where it will now be stored until you decide to overwrite it with another!

In the Media

Joe Strosnider's Video Review

Joe Strosnider's Updated Video Review

ROMX was reviewed in the June 2021 issue of Juiced.GS magazine!

Please note hardware requirements below.

Hardware Requirements : ROMX will work in any Apple II but its functionality may be limited by the amount of RAM in the machine. Currently, with pre-release software you get full functionality in machines that have at least 32K of RAM. With less RAM, you can install a pre-configured board into a machine with as little as 4K but you will only get a simplified menu that lets you switch banks. The board can be pre-configured (images loaded, defaults set ,etc.) in another Apple II with 32K or more. Firmware upgrades are easily done with a file download from and the Upload Image command in ROMX.

The Text ROM is currently designed to replace the 2316B SPCL ROM used in the rev 7 motherboards onward. Rev 7 motherboards are quickly recognised by the lack of the RAM jumper blocks. If you have RAM jumper blocks then you will need the 2513 version of the text ROM.