jon@csd4.milw.wisc.edu (Jon George Seidl) (03/05/88)
Hi,
I'm looking for a way to reset my C64 to power-up state without turning it
off and on. It should be a hardware reset (a little red button or something).
Is there "gentle" way to do this (like temporarily opening a low-current
connection someplace that won't fry chips after a few uses)? If so, are there
schematics out there for doing this? I've seen something like this on cartridge
expansion port modules.
Jon
---------------
\_/ \/\/ - /\/\ilwaukee "Oh these? umm...
no, nothing kinky like
Internet: jon@csd4.milw.wisc.edu that, they're just...
bitnet: jon%csd4.milw.wisc.edu@wiscmac3.bitnet ummm...souvenirs."
Uucp: uwvax!uwmcsd1!uwmcsd4!joncs161aan@sdcc18.ucsd.EDU ({Darkavich}) (03/05/88)
there are two ways to hook up a reset to your c-64
The best, is to wire pin 2 and pin 6 of the disk drive port on the
serial I/O If you are looking at the back of the c-64
5 / _ \ 1
6
4 | | 2
|
3
hook an always open switch to those two pins.
if you do not wish to solder a switch some stores carry a small box
that plugs into the drive port and the drive cord into it.
It has a push button switch to reset. (this does exactly the same
thing.) For about 10 bucks as apossed to $.18 for the switch at
Radio-Shack
Another way and i do not recomend this is to put a reset switch on
the power supply-- This can be dangerous if not done proporly, so I
will not mention it.
the advantage to the first way is if you are working on assembly
code and you lock up the computer, you can reset and the code is
still in memory, just basic is wiped out.
This is great for listening to "30120 music"
Good luck,
Steven Misrack
cs161aan@sdcc18.ucsd.EDUGeoffrey_Welsh@watmath.waterloo.edu (03/05/88)
> From: jon@csd4.milw.wisc.edu (Jon George Seidl) > Message-ID: <5061@uwmcsd1.UUCP> > Date: 4 Mar 88 21:32:53 GMT Jon: There was a huge debate in the FidoNet "CBM" conference on the pros and cons of shorting RESET to GROUND. The schematics (or at least the ones I have!) show that the RESET line is fed through an open-collector driver, meaning that you can hold RESET low as long as you like and not harm any chips. Some claimed that their C64s did not use OC drivers on the RESET line; I doubt the accuracy of those claims. Bottom line: short the RESET line to GND for as short a period as possible. If you feel like a genuine hacker, try shorting pin 8 of U20 (a 556) to GND - that's the trigger pin of the timer. It might (should?) reset the machine and it's driven through a 1 meg resistor to +5v and a 0.1 uF cap to GND, so shorting it should be completely harmless but generate the required RESET signal. Geoff ( watmath!fido!221.171!izot ) --- ConfMail V3.31 * Origin: The Waterloo Window: WOC's out there? (1:221/171)
elg@killer.UUCP (Eric Green) (03/07/88)
in article <907@sdcc18.ucsd.EDU>, cs161aan@sdcc18.ucsd.EDU ({Darkavich}) says: > there are two ways to hook up a reset to your c-64 > The best, is to wire pin 2 and pin 6 of the disk drive port on the > serial I/O If you are looking at the back of the c-64 Note that some 64s, at least, have the disk drive reset isolated from the computer reset by virtue of a spare 7407 that was hanging around. Fiddling with disk drive reset on such computers is futile (unless it's your drives that need re-setting!). Me, what I did was take one of those 19c pushbutton switches, solder a couple of wires to it with microclips on the end, and then whenever I'm forced to use someone else's computer, I take my reset with me! Since some schematics are in the back of the Programmer's Reference (and are generally accurate, except for the video output section which has been very much changed), it's fairly easy to find a ground and a reset line. Note that it really would be best to put a couple of clamping diodes near your switch, to avoid inductive kick. But I doubt that those little Rat Shack switches have enuf metal in them to function as an inductor :-). At least, I've never had a problem. -- Eric Lee Green elg@usl.CSNET Snail Mail P.O. Box 92191 {cbosgd,ihnp4}!killer!elg Lafayette, LA 70509 "Human evolution ended when civilization began".
jon@csd4.milw.wisc.edu (Jon George Seidl) (03/08/88)
In article <17327@watmath.waterloo.edu> 221.162.fido!Geoffrey_Welsh@watmath.waterloo.edu writes: > > There was a huge debate in the FidoNet "CBM" conference on the pros >and cons of shorting RESET to GROUND. <...stuff deleted...sorry...>. > Taking a step back to shorting pins (what was it? 2 and 6) of the serial I/O port to reset the C64, I finally got in touch with our local Electronics guru. He told me that hooking a normally-open push-button to those pins WILL give me the reset I want. However, he also told me that sending a static electricity spark through that button will quite possibly fry the CPU. He suggested using a opto-isolator with the reset. So, that will probably be the path I take. Rather safe than sorry. By the way, THANKS TO EVERYONE WHO ANSWERED MY QUESTION! Jon --------------- \_/ \/\/ - /\/\ilwaukee "The only difference I noticed is that while Hackers had floppy disks, Internet: jon@csd4.milw.wisc.edu Computer Scientists had hard disks." bitnet: jon%csd4.milw.wisc.edu@wiscmac3.bitnet -Amy G. Uucp: uwvax!uwmcsd1!uwmcsd4!jon
lishka@uwslh.UUCP (Christopher Lishka) (03/10/88)
I have an old C64, and shorting reset to ground is exactly how I
constructed my reset button. I don't remember the details because it
has been years since I performed the operation, but I do know that my
C64 has worked fine throughout all those years, although I did make
sure to keep the button pressed for only short periods of time (i.e. I
wouldn't hold it down for several seconds). The circuit consisted of
only a momentary switch from Radio Shack; i.e. there was no fancy
electronic timing involved.
-Chris--
Chris Lishka /lishka@uwslh.uucp
Wisconsin State Lab of Hygiene <-lishka%uwslh.uucp@rsch.wisc.edu
"What, me, serious? Get real!" \{seismo, harvard,topaz,...}!uwvax!uwslh!lishka