
Load games instantly with FinalGrom99
The cartridge FinalGrom99 is an open source development by Ralph Benzinger (endlos99), who after the great reception of his previous development FlashRom99 in 2016 decided to give it a twist and make a more complete version, adding:
- GROM image support
- Support for images up to 1 MB, via ROM write paging
- Providing RAM and GRAM programmes through advanced modes
- Execute another program located on the SD card from another program or dump its state to the SD.
- SD and SDHC card support

FinalGrom99 for Computer Texas Instruments TI-99/4A
FinalGrom99 at a glance
The use of the cartridge is simple: just copy the desired image files to the SD card (you can copy them to the root or organise them in different folders) and once copied, insert the SD card into the cartridge. Making sure that the TI-99/4A is switched off, place the FinalGrom99 in the "Solid State Software" slot and switch on the TI-99/4A.
The activity indicator of the FinalGrom99 cartridge will start flashing once it is switched on. Wait until it stops flashing and you can either press a key to display the main menu, or press the FG reset button on the FinalGrom99 to force it to initialise.

Once the TI-99/4A is booted with FinalGrom99 and an SD containing an image, the main menu will show the familiar "Press 1 For TI Basic" and a new option: "2 For FinalGrom 99".
When this menu is displayed, just press "2" and the FinalGrom99 menu will be initialised and the contents of the SD card will be displayed:

FinalGrom99 with firmware version 1.3 showing 1 of the 2 pages of files contained in SD
As you can see in this video, the operation is really simple: with just two keystrokes and after a few seconds we can be enjoying any TI-99/4A game we want:
FinalGrom99 cartridge box
The FinalGrom99 board fits perfectly into the original TI-99/4A standard cartridge case. Only the necessary holes for the SD slot and the FG Reset and TI Reset buttons need to be drilled.
Another possibility is to 3D print a cartridge sleeve such as the designed by Remo_WilliamsHowever, if you don't have a 3D printer or you prefer to receive the cartridge with its own box, we can provide you with the box together with the FinalGrom99 board.
In order to avoid having to make supports for the inside of the cartridge, we have divided the upper part of the cartridge into two separate parts which are then assembled together. This shortens the printing time and reduces material costs.
FinalGrom99 PCB

The archives gerber and the BOM can be found in the Ralph Bezinger's GitHubas well as future firmware updates.
Firmware update
The update of FinalGrom99 can be done via an SD card. There are several update files, which must be copied to the root of the card. Depending on which component you want to update, these are the specific files:
- Atmega 328P microcontroller - Update via UPDATE.AVR file
- Xilinx CPLD XC95144XL-10TQ100 - Updated by UPDATE.PLD file
Need a FinalGrom99? complete the form and we will get back to you as soon as possible.