Thanks Mike, I did find one datasheet that said "don't care" but others that specify 5V. Good advice, thanks-
On Thu, Mar 10, 2022 at 3:32 PM Mike Stein <[email protected]> wrote: > Don't know about the 27C256 but experience with 2732s was that with some > manufacturers you could get away with leaving it to float whereas on others > you had to explicitly pull it high (which would be my recommendation). > > m > > On Thu, Mar 10, 2022 at 2:20 PM Stephen Adolph <[email protected]> > wrote: > >> Quick one for the crowd. >> On a 27C256, I have always thought you could ignore Vpp for normal use, >> and only use it for programming. >> >> So, you could plug a 27C256 where the main rom lives in a T102 or T200, >> or UK M100, or KC-85, or M10. whew. >> >> However, when I look at datasheets for 27C256, they all say normal >> condition on pin 1 is VCC!!! >> >> What gives? >> Is it ok to float pin 1, or really should we be connecting pin 1 to plus >> 5V? >> >> thanks >> Steve >> >
