Thanks so much for the reply!

Disabling Fast Boot seems to have solved the problem! Awesome!

I've tried to find a thread here addressing this and didn't see one. I haven't exhaustively searched BYOAC, so please forgive my ignorance if it's already posted there.

My setup:

XFX - AMD Radeon R5 220 2GB DDR3 PCI Express 2.1 Graphics Card (identifies as a Radeon HD 6450 in Device Manager)
Gigabyte B150M-DS3H motherboard
Core i3 3.8Ghz. 
CRT Emu driver 2.0 beta 8


Since the ATOM-15 flash:

On a cold boot, the Windows desktop screen comes up with a vertically shrunken picture. I suspect is related to the following note, since it appears some horizontal lines aren't being drawn due to an interlace issue.

[26/01/2016][CRT Emudriver 2.0][CRT Tools 2.0][beta 7]

  - [Emudriver]  Forced reset of interleave flag upon device power-up. Fixes problem with ATOM-15 flashed cards that caused a shrinked picture with progressive modes and double picture with interlaced modes.

The vertically shrunken picture affects all resolutions in Windows. If I simply reboot the PC, the Windows desktop come up looking  fine. I'm probably oversimplifying, but is it possible to disable the "forced reset" of the interleave flag upon device power up? I'm curious if that might fix it.

Thanks for the excellent software, Calamity! And thank you to everyone else for taking the time to read this as well!

Confirmed working:

XFX - AMD Radeon R5 220 2GB DDR3 PCI Express 2.1 Graphics Card

This card is listed as a "Best Buy" exclusive and can be had for $49.99 as of late August 2016. It's passively cooled and, as you might expect, isn't a very strong 3D performer. This card also exists in a 1GB version for about half the price. While I can't confirm the 1GB model will work, I strongly suspect it will.

The card shows up as a Radeon HD 6450 in Device Manager, so I'm thinking AMD rebranded this model.

ATOM-15 worked great on this card's BIOS. My UEFI POST screen is now visible on my WG D9400 Trimode monitor. (prior to flashing the modded BIOS, I was getting "Over Range" until Windows booted) I am using Windows 10 x64 on a Gigabyte B150M-DS3H motherboard with a Core i3 3.8Ghz. 

This setup works great for MAME and Sega Naomi emulation. I also am able to run Street Fighter 4 for the PC at 60fps as long as I don't have all the gfx settings cranked. I do have most of them set fairly high though.

One minor bug I've noticed since the ATOM-15 flash...

On a cold boot, the Windows desktop screen comes up with a vertically shrunken picture. I suspect is related to the following note, since it appears some horizontal lines aren't being drawn due to an interlace issue.

[26/01/2016][CRT Emudriver 2.0][CRT Tools 2.0][beta 7]

  - [Emudriver]  Forced reset of interleave flag upon device power-up. Fixes problem with ATOM-15 flashed cards that caused a shrinked picture with progressive modes and double picture with interlaced modes.

This shrunken picture affects all resolutions in Windows. If I simply reboot the PC, the Windows desktop looks fine. I'm hoping there's a simple fix or option I can change for this. I'm going to post this in the other section of this site for reference. (I am running beta 8, btw)

In closing, thank you Calamity for making this possible!