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.
I realize that 27C256 is common but which one ? Could you help me identify compatible model ?
Found in MAME Arkanoid driver :
MMI 63S241 bipolar PROMs. Compatible with MB7116, 7621, DM74S571N etc
BPROMs are silkscreened as 7621, actual BPROMs used are MMI 6306-1N
for a75-07.ic24, a75-07.ic23 and a75-07.ic22
I can find blanks MB7116E.