I forgot to mention the most "exciting" part of this hack. My (UV) EPROM programmer was an ISA-based peripheral and the 386 was my only PC (with an ISA bus), s

I forgot to mention the most "exciting" part of this hack. My (UV) EPROM programmer was an ISA-based peripheral and the 386 was my only PC (with an ISA bus), so I booted it up and then removed the EPROM from the socket on the motherboard, put it into the programmer to get an image (because I did not have confidence that the copy in RAM hadn't been altered), then reversed the image and burned a new EPROM. (If I hadn't used a new EPROM, I would have rendered my computer useless with no way to revert.) Fortunately I had a UV eraser so I could give it another go when the first iteration didn't work.