Re: Apple II Minus Question

["Vince Briel" <vbrielnospamme@comcast.net>]

You can perform a manual reset without the keyboard simply by applying a
ground to pin 40 of the CPU. This is exactly more or less what the reset key
does.

--
Replica I
The Apple I clone

http://www.applefritter.com/apple1/members/replica1/index.htm
"Bryan Parkoff" <bryan.nospam.parkoff@nospam.com> wrote in message
news:aq30c.16730$OH4.2906@fe2.texas.rr.com...
> Bill,
> > So, therefore, if Bryan is starting up and
> > no monitor prompt comes up on RESET, then
> > the CPU is probably at fault, but since it
> > works in another board, then the fault is
> > a trace on the 5v line somewhere. This is
> > provided the RESET key is working at all.
> > I wonder now if he has tested the keyboard
> > on another motherboard.
>     Yes, I have tested three keyboards to another working Apple II
> motherboard.  They are functioning fine.
>
>     I give you an example.  GR and HGR are not working on second
motherboard
> while Old Monitor Routine is not powered up on first motherboard.  I tried
> to swap ALL 74xxxx and DRAM chips from working motherboard to both
defective
> motherboards.  The status is still the same.  There is no solution for Old
> Monitor Routine Start-Up and GR & HGR working.
>
>     I must admit that it is necessary for me to purchase electronic
> diagnostic equipment to test three defective motherboards.  I still have
> voltimeter.  Is it worth to obtain several different diagnostic tools?
>
> --
> Bryan Parkoff
>
>