On 04/16/2018 06:11 PM, CuriousMarc via cctalk wrote:
  And lifting the sticker reveals the BIOS chip is just
a W29C020P-12, a
 regular 256k x 8 Flash memory, 5V chip. Duh. Mystery solved. Of course way
 newer and with many more address lines than my DataIO 29B can read and
 program. Time has come to buy a small, modern, cheap, infinitely capable
 Chinesium EEPROM programmer. Read: the kind of practical, affordable,
 sensical and useful equipment I usually steer away from. Ebay here I come.
 Or make a programmer with an Arduino, since it's 5V. 
Hmmm, you don't happen to be a subscriber to AvE's Youtube channel, perhaps?
--Chuck