Mitchell Spector<mitch2gs@hotmail.com> wrote in
lk6k569vb7hjf7e35410crf0c48jlhdkcp@4ax.com:">news:lk6k569vb7hjf7e35410crf0c48jlhdkcp@4ax.com:
The Elfe<email@nospam.com> wrote:
Less common to find, at least in my experience, is the original IIc
motherboard with serial port timing glitch (identified by the presence
of a 72LS161 chip rather than a tin oscillator). Also less common is
a IIc with the 'ROM 4' firmware. Or better yet, 'ROM 5', which is the
IIc Plus. :) None of these are rare per say, just less common.
I'm living in Europe.
Mine has 2 problems: one is when I press CONTROL+RESET, I could nothing
type, for the cursor was moving endless
>from time to time with some strange patterns and some beeps. Well I
have
to find another motherboard, I think, aye.
Sounds like certain keys are stuck, either physically or due to
the fault of failed circuit logic, like the keyboard encoder chip.
The original ROM (255) had no built-in self test diagnostic,
however if you pressed Apple + Control + Solid-Apple you'd
get something like you describe. Could be the Solid-Apple
key is stuck, or shorted because of an attached joystick.
Could also be bad DRAM's on the motherboard, though
the only way to tell is to run a floppy disk based diagnostic.
I'd recommend the Apple II Diagnostic from Apple.
Mitchell Spector
Well, the original ROM (255) has a "almost"built-in self test
diagnostic... but neverending. I know that I can start the diagnostic,
stop the working disk drive. So it could be a bad ram or keyboard encoder
chip. is there a means to check this chip?
Thank for your help,
The Elfe