someone recognizes this eprom conversion ?

[techy]

found this inside my french ql ,

it has embedded lightning .

i would like to know what conversion system has been used to get 2 x 27c256 in place of the original roms .

AND i would like to know how to burn such adapted eproms .

in the sockets are ttl chips embedded which are connected to several pins of the eproms .

[Chr$]

That's a home made adapter with a 27C512 EPROM ( I think) and the chip buried underneath is probably a 74LS00 (or equivalent). It's a bit fiddly, but not that hard to make something like that. You can also change the jumpers on most boards to accept an EPROM and some even have a socket for the required 74LS00 logic chip.

[techy]

Thanks for your answer !!

it is 2 x 27c256 eproms .

Is this modification described somewere ??

[Pr0f]

I think the confusion is whether there are 2 physical modules like this or 1 - as you never show a picture with both in

[techy]

ah , sorry , they are next to each other so occupy both original rom positions .

there are no wires outside the socket connected to the board .