ID UV erasable PROMS used on an IBM PC board?

[D. Resor via cctalk]

I cannot find a datasheet by any of the numbers silkscreened on these ICs.
 
Could these be proprietary IBM P/N numbers?
 
https://www.dropbox.com/s/f6rvemx9ldbbv5x/EPROMS1.jpg?dl=0
 
No need for a Dropbox account, close the login pop up and you can view the
image.
 
Thanks
 
Don Resor