The TI 99/4A Flash ROM Cartridge, or FlashROM 99 for short, is a cartridge for the TI 99/4A home computer that allows for running ROM cartridge images stored on an SD card.

The FlashROM 99 supports ROM-only images of up to 32K that use the write-to->60xx bank switching scheme. It will not work with programs using GROMs or CRU-based bank switching. The cartridge does not require the Peripheral Expansion Box and runs on both PAL and NTSC consoles.

FlashROM 99 is released as Open Source Hardware under the CERN OHL license and the GNU GPL license. Both hardware design files and firmware sources are available on GitHub.

The project homepage is hosted at GitHub.

Gallery:

Download: FlashROM 99 SD Card (1207)

source: endlos99.github.io/flashrom99 ti99iuc.it

Texas Instruments TI-99/4A – Navarone’s Widget Multi Cartridges Fixed.

Works that have been made:

• Annoying short circuit under the cartridge connector on the slot 3 between the pins: 4,6,8,10

Texas Instruments TI-99/4A – Alpha Lock Joystick Fix.

This mod fix the problem of the alpha-lock key that need to be up or down when you are using joysticks.

The instructions for the Alpha-Lock Joystick Fix can be found here

Texas Instruments TI-99/4A – CPU Overclocked at 3.58mhz

This project allows you to increase the speed of your console from 3mhz to 3.58mhz. It might not sound like a big increase but this is a 20% increase in speed and it is easily noticable.

The instructions for the CPU Overclock modding can be found here

Gallery:

Texas Instruments TI-99/4A – Internal TMS5220 Speech Synthesizer.

The instructions for the internal assembly of the TMS5220 Speech Synthesizer can be found here

Gallery of the works that have been made:

It could be better!

I had severals problems with the free space inside the TI-99/4a, maybe i have put too many things … but everything works perfectly :D

Texas Instruments TI-99/4A – 32k Internal Expansion Memory + Status LED + Reset.

Works that have been made:

• 32k Internal Expansion Memory.
• Switch for disable the Expansion Memory.
• Reset Pushbutton switch.
• Bi-Color LEDs to display the status of the internal memory expansion 32k. (ON = Green / OFF = Red)
• Replaced the resistor for the LED from 2.2k to 220 ohms.

Gallery of the works that have been made:

It could be better!

I had severals problems with the free space inside the TI-99/4a, i had to remove one side of the metal part, the biggest problem is the internal 32k expansion which is not very well done, there is no a way to secure it inside … but everything works perfectly :D

Texas Instruments TI-99/4A – F18a (FPGA Based TMS9918A) Installation.

Works that have been made:

• Installation of the F18a and removal the tape connector to make a opening for the vga connector.
• The metal cover is no longer used.
• RCA 2 DIN Homebrew Adapter to use the audio output after installing the F18a on the TI-99/4a.

Gallery of the works that have been made: