Hi Phil,"phil" <pjwylie@gmail.com> wrote in message be09de50-2593-40da-8db0-7d0927b85a43@w37g2000prc.googlegroups.com">news:be09de50-2593-40da-8db0-7d0927b85a43@w37g2000prc.googlegroups.com...
Hello, I have a //c that gives a screen full of characters when turned on. Mostly 2 rows of @ symbols and 2 rows of square characters. There is no beep. the drive doesn't try to read, and the self test with the closed apple key pressed doesn't run at all (no idea why), Is this because of bad RAM? If so, does anyone know where to buy the MT4264-20 chips in Australia? Or something compatible? Thanks esp. to datajerk for help last time, I'll get there eventually with the ftp to apple transferrring. Phillip.
What leads you to think the RAMS may be faulty? Do you have a logic probe? I'd begin by checking for activity at the clock input on the 65C02. If it is the case that the RAMS *are* faulty... Stock standard 4164 rams will do the job. Futurlec keep them here in Oz, $2 each: http://www.futurlec.com.au/Components.jsp Look under Integrated Circuits -> Memory -> Rams Cheers, Red