"reset" C64?

Zane H. Healy healyzh at aracnet.com
Thu Sep 7 19:56:18 CDT 2006

> On 9/7/06, Josef Chessor <josefcub at gmail.com> wrote:
> > On 9/7/06, Zane H. Healy <healyzh at aracnet.com> wrote:
> > > Is there an equivalent to CTRL-ALT-Delete on the C64 so you don't
> > > have to turn it on and off every time you want to run a new program?
> >
> > RUN/STOP-Restore is what you're looking for, but with many programs it
> > doesn't work due to their hijacking of the metal from the ROM.
> Other people have pointed out the /RESET line on the User Port; I thought
> I'd just point out that the RESTORE key goes right to the /NMI line.  The
> normal trap handler checks the keyboard for RUN/STOP and resets BASIC
> (if it can).  That's why it's important to press RUN/STOP, _then_ tap
> RESTORE.  If you try to hit both at once, you might get the timing off
> just enough that you initiate the interrupt barely before you've pressed
> RUN/STOP, in which case, the NMI routine will do nothing.
> In any case, commercial software routinely routed the NMI vector to
> a do-nothing routine to prevent you from trapping out to BASIC.  Rig
> up a /RESET switch off of the User Port (look up the User Port pinout
> in your C= Programmer's Reference Manual to get the correct pin).
> -ethan

Apparently this hack allows you to do a cold reset by pressing the RESTORE
key.  http://commodore-gg.hobby.nl/forum/viewtopic.php?t=454  

The idea of taking a soldering iron to one of my C64's appeals to me, I
still have the soldering Iron that was purchased to work on my VIC-20 :^)
Though I'd use a better one that I now have.  Hanging the switch off the
User Port is likely to be the easiest, as I might have everything I need to
do it at home.

At the same time, I see that the "Retro Replay" cart can apparently do a
reset, and I've been threatening to get one anyway.  With the optional
ethernet it looks most tempting :^) Though the "Retro Replay" cart and
RR-Net aren't cheap :^( On a related net, I managed to boot the Contiki OS
last night, and would love to be able to try the telnet client that comes
with it  :^)


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