TL866 Won't Erase or Program W49F002U

[Quarlo Klobrigney]

I'm trying to flash the BIOS of an old ECS computer because I need XP to work with some old software.
The computer booted up with an AMD 1400 just fine.
After I swapped the CPU for a 2000, it rebooted again just fine.
After accessing the BIOS to set the CPU multiplier clock, I got as far as entering the BIOS screen.
It then locked up. Yes the CPU is supported, and rebooting resulted in nothing.
Swapping the CPU back, the computer beeps, and results in no video on the monitor.
 
Resetting the BIOS did nothing.
Looking at the manual it will default to a PCI video card. Out with the AGP, in with the PCI card.
The monitor says wrong resolution for any PCI card I use.
 
Now to the bigger issue. The flash chip is a DIP 32 so direct plugin to the TL866 ver. 6.85.
The original file was 2 years older and I wanted to update it.
I read and saved the original first of course.
I have 2 BIOS ROM files, which I attempted to update and flash it, but the TL866 was having none of it.

I checked for a blank IC it said no.
No matter what I do the original file is still on the chip.

Does anybody have an idea why I can erase the IC but can't program it?
I don't see why, it's not OTP.

Here's a datasheet.
https://datasheetspdf.com/pdf-file/1233812/Winbond/W49F002U/1

[Quarlo Klobrigney]

It fails in the programming process at address 0x00D336.


I can repeatedly erase successfully and an empty check shows it's not empty at address 0x00C080.


Here are some photos.