Hi,
Was advised to send a write report for this chip, so I tested all possible operations, using a W29C020-12 on a Freetech P6F91i motherboard, and everything works brilliantly. Logs attached.
By the way, even if this is a very old board, I'll just point out that if you ever want to convert a 1Mb BIOS P6F91i to a 2Mb BIOS one, you just need to place a jumper between pins 2 and 3 of JP1 to have the extra address line (being mindful that pin 1 of that jumper is 12V and must be left alone).
Regards,
/Pete