info-mac@uw-beaver (12/08/84)
From: John <Roach@RUTGERS.ARPA> Is it better to hit the programmer's switch to reboot the system, or should one turn the machine off and back on? Some local dealer suggested that using the programmer's switch could damage the machine, ie., repeated use would 'fry the electronics' and all sorts of bad things. They said that this switch should only be used to recover from a application that had hung, etc. Does anybody know which is safer as far as the hardware is concerned? John. -------
info-mac@uw-beaver (12/10/84)
From: olson@harvard.ARPA (Eric Olson) Never listen to dealers. They know almost nothing except whether they have a certain product in stock. Of course it's safer to use the programmer's switch than to power-cycle the Mac. I've been using it for a year, and I have NEVER had a problem (not even with trashing disks due to indescretion). I sometimes use it to clear the desktop and change startup disks, since it is more thorough than launching a new finder. Anyone who says that something will "fry the electronics" doesn't have much knowledge to back up their remark. Consider it an old wives' tale. Eric.
info-mac@uw-beaver (12/13/84)
From: Nick <NNicoll.ES@XEROX.ARPA> Re: Programmer's switch Anybody give me some tips on insalling that sucker. I can't get the tabs to fit thru the cooling vent. Re: Never listen to dealers. They know almost nothing except whether they have a certain product in stock. I second that emotion. Don't even listen to dealers if they say they do/don't have something in stock. I'm fairly happy with my local Computique store and (probably because I paid cash for the first 512K Mac he sold) the manager will go out of his way to be helpful to me BUT; I can't trust the other people who work there to give me straight information on stock, they seem to try to figure out the answer I would like to hear and then give that and at two local software houses I was told on the phone they did not have the item I was requesting but, when I stopped to buy some disks on my way home from work it was sitting on their shelves (I drove over to the second store just to see). I asked each store if they had had a delivery today and got "No, are you looking for something special?". <<plaintive tone>> when will (especially automotive and computers but all stores, really) dealers give remote access to their open stock situation? \\ Nick
info-mac@uw-beaver (12/13/84)
From: olson@harvard.ARPA (Eric Olson) General Computer Company has informed me that they will be gearing up dealers to take Hyperdrive orders beginning January 2nd. We'll see. I want one. -Eric.
info-mac@uw-beaver (12/21/84)
From: Hess@MIT-MULTICS.ARPA I believe that there is some good reason to use power rather than programmer's switch in some cases. We have been having continuing troubles with our external drive trashing the developer's disks, and powering off rather than switch-rebooting seems to ameliorate the situation. Do any of the people who are having problems with external drives NOT have the programmer's switch installed? For that matter, I wonder how many people on this list do NOT have it in... Brian Hess.Unicorn @ MIT-Multics
info-mac@uw-beaver (12/22/84)
From: olson@harvard.ARPA (Eric Olson) I read a good theory in INFO-MAC a while ago about why external drives sometimes start trashing disks. The programmer's switch/power off issue may seem to help, but I think it helps by side-effect only. To summarize: The external drive sits in some random position outside the Mac. When the mac reboots (via power cycle or programmer's switch) it resets the video controller (possibly) causing a massive collapse of flux in the flyback transformer (or some other transformer). If the read/write head in the external drive is in the path of this field, its head could become semi-permanently magnetized. It will then trash disks inserted because it writes all over them with a (semi-permanent) magnet. To cure this problem, the suggestion was made to take a disk and keep inserting it in the drive and formatting it. This will put the write-bias current through the head a lot, and hopefully demagnetize the head. Putting a plane of conductive metal (like a cookie sheet) between the Mac and the drive cured the problem [I wish I could take the time to attribute the creator of this wisdom, but I can't look through the archives for that-- leave it at: this isn't original thought]. Considering that the power cycle is probably much more fluxxy than the programmer switch reset, I wouldn't recommend using the power cycle to get the machine to behave better. It's just possible that power-cycle works both ways: sometimes magnetizing, sometimes demagnetizing. Whatever. -Eric [For those of us without cookie sheets, would it be wise to always position the external drive on the RIGHT side of the Mac, farthest away from the fly back transformer(?) --bc]