27C256 are pretty common as far as I know.
MC68705P5S it’s also OK from buyICnow
MB7116E aren’t so easy to find. I can see 6306-1N on other boards. Which one ? And how can they be burned ?
I can consider buying programmer to play with that can be helpful later.
with a very old programmer.
i can do a lot of them, a number of other people here can too.
*but* the blanks are hard to get and you cant erase them - so buying of ebay is risky incase they are already programmed.
there is a polish supplier on ebay that may have them - i'll have to check the company name and get back with it.