Thanks Brian. I have a test clip that will work i think I'll just use that.
On Tue, Nov 28, 2023 at 09:49:48AM -0500, Brian K. White wrote: > On 11/27/23 11:48, runrin wrote: > > Do you know if it's possible to dump the original ROM using the > > programming adapter for the FlexROM 100? > > Maybe. > > There are two things to worry about and I'll just think out loud right here. > > 1 > The programming adapter presents a pinout for a 28C256, not a 27C256 or mask > rom. Those are only a couple wires different, but then again, since it's > just for reading, and the read cycle is the same, you could just tell the > programmer that it's reading a 28C256 (force it, override chip id > detection), and that won't hurt the rom. > > 2 > Pin 23. The programming adapter routes pin 27 from the programmer (/WE if a > 28C256 were in the programmer) to pin 23 of the DIP socket, which is ALE on > the LH535618 rom, but the flexrom board connects it to the /WE pin on the > actual 28C256 on the board. > > I *think* what you want to do is take a DIP-28 socket and bend out pin 23, > connect the bent-out pin 23 to pin 27, put the modified socket into the > programming adapter and then the old rom into the modified socket. Then tell > the programmer to read a 28C256 and ignore chip id. The socket is just to > avoid bending the leg on the old chip. > > IE, feed /CE from the programmer to both /CE and ALE on the chip, and don't > connect anything to /WE at the programmer. > > But, at that point it's almost simpler to just make the entire adapter > manually with two dip sockets and wires. Especially since it's a one-off. In > that case, use a 27C256 pinout and tell the programmer to read a 27C256 > instead of 28C256. > > But if your chip has any of these part numbers, then it's already been > dumped. > https://bitchin100.com/wiki/index.php?title=Model_and_ROM_information > > -- > bkw >
