Project Update

Video Bios

The attached vpatch.c does not include the flashing routines, it requires more testing. This simply updates the bios in memory which is useful for testing the XR values to get it tuned in exactly where we want and verify functionality. Unfortunately I do not believe you can enter easy setup from a warm reboot.

When the program is run it checks to make sure the bios in memory is what it expects, and then changes the required values. A reboot (ctrl-alt-del) is required for the video bios to re-run its initialization routine. I do this as I am simulating if the flash had been updated. To make this a functional temporary patch it would be possible to set the XR values in the CT65535 registers on the spot as well, or potentially re-call the initialization routine.

The changes will stay in memory until the power is reset or a hard reboot / jump to FFFF:0000 occurs.


I am using my V3 PCB for testing. I have not modified the 3D printed bezel yet so it cannot fit flat as there is not quite enough space so I have just glued it standing up for testing and cut the window as needed.

I want to be sure the DC-DC I have selected is suitable before spending more time on the mechanical aspect of fitting it. I had one fail, the output capacitor failed to a short. This burned out the 630mA fuse on the PC110 inverter board.

On the next revision of the board I will be including a fuse below 630mA to try and prevent any faults in the TFT retrofit blowing the PC110’s inverter fuse as it requires the entire unit to be taken apart to properly replace it.

I currently have the onboard PIC10 set to control a fixed 5% backlight brightness while I investigate the DC-DC’s and what an acceptable max brightness is.

Trial Run Modified Bios

Here is a test run with a bios modified and programmed outside of the PC110 to demonstrate the end goal. The screen is not properly aligned as there are still a couple registers I need to properly update.

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