AbelVincze Posted December 28, 2013 Report Share Posted December 28, 2013 Me again, i can now confirm, that applying this OC will prevent MacsBug to load at boot time. I liked a lot the additional speed, but as i want to use these machines for development, the OC is not an option for me. Tested OS, 7.5.3, 7.5.5, 7.6, 7.6.1 Quote Link to post Share on other sites
uniserver Posted December 28, 2013 Author Report Share Posted December 28, 2013 What is MACSBUG? Also the re-clock we'll call it, makes it a LC-III+ witch is a legitimate model. are you sure you are not doing something odd? Quote Link to post Share on other sites
AbelVincze Posted December 28, 2013 Report Share Posted December 28, 2013 What is MACSBUG? Also the re-clock we'll call it, makes it a LC-III+ witch is a legitimate model. are you sure you are not doing something odd? MacsBug is a debug console on the Mac, invoked by NMI (command-power btn) http://en.wikipedia.org/wiki/MacsBug R14 soldered out, and soldered on the empty place R74... I tested the solderings, and as everything was ok finally (except macsbug, and model type recognition) i think the OC was done correctly. Quote Link to post Share on other sites
LCGuy Posted December 29, 2013 Report Share Posted December 29, 2013 If you have a flat PRAM battery, or no PRAM battery and you're running 7.6, the double-boot is normal - the first boot puts the Mac into 32 bit mode (required for 7.6 or later), and reboots it. Quote Link to post Share on other sites
unity Posted December 29, 2013 Report Share Posted December 29, 2013 If its a 000 ohm resistor, would that not mean in fact its not really one at all? Basically a wire link. I know other Macs where instead of moving small resistors one could just create a solder bridge instead. The "resistor" was used simply because it was an easy part to drop in on the board when different combinations of connections applied to different speeds. Quote Link to post Share on other sites
AbelVincze Posted December 29, 2013 Report Share Posted December 29, 2013 I'm wondering is it possible to make an internal switch, so it would be possible any time to switch OC on/off... Quote Link to post Share on other sites
unity Posted December 29, 2013 Report Share Posted December 29, 2013 I'm wondering is it possible to make an internal switch, so it would be possible any time to switch OC on/off... Yes, if its a 0 ohm resistor you could add a switch. They makes switches with multiple contacts that would effetely break one connection and make another in one flick. Quote Link to post Share on other sites
uniserver Posted December 29, 2013 Author Report Share Posted December 29, 2013 double throw, double pull will do it. http://www.mouser.com/ProductDetail/TE-Connectivity-Alcoswitch/A103SYCQ04/?qs=sGAEpiMZZMvudeGI7i40XE%2fMmrHHHc8pUQGytYsMK0I%3d flip 25mhz flip 33mhz as they are saying, 000 ohms is the same as a solder bridge, just its machine loadable when they are populating boards. just use some wire wrap to connect the pads to the switch. Quote Link to post Share on other sites
techknight Posted December 30, 2013 Report Share Posted December 30, 2013 Eww... keep those wire leads short if you use a big switch like that, otherwise youll end up with clock skewing and other weirdness. Quote Link to post Share on other sites
uniserver Posted December 30, 2013 Author Report Share Posted December 30, 2013 your right… i was being cheap and going by price… this switch is going to work out much better http://www.mouser.com/ProductDetail/Mountain-Switch/10TC415/?qs=sGAEpiMZZMvudeGI7i40XFvpMq5YRs7w6zlonyB%252bgAs%3d Quote Link to post Share on other sites
techknight Posted December 30, 2013 Report Share Posted December 30, 2013 it doesnt specify the maximum frequency at which you can apply through that switch before leakage becomes a concern. Quote Link to post Share on other sites
mac512 Posted April 25, 2020 Report Share Posted April 25, 2020 I'm sorry to resurrect such a long dead thread. I'm thinking of performing this upgrade. However, I'm concerned about the stress on the 25MHz CPU (mine is not a down-clocked LC III+ motherboard but the original with the 25MHz CPU). Would it be too much for the 25MHz CPU in the long run? Thanks! Quote Link to post Share on other sites
MrFahrenheit Posted November 30, 2020 Report Share Posted November 30, 2020 On 4/25/2020 at 12:14 PM, mac512 said: I'm sorry to resurrect such a long dead thread. I'm thinking of performing this upgrade. However, I'm concerned about the stress on the 25MHz CPU (mine is not a down-clocked LC III+ motherboard but the original with the 25MHz CPU). Would it be too much for the 25MHz CPU in the long run? Thanks! And again, sorry for ancient resurrection as well (this one only 7 months later): I think if you attach some good heat sinks it would help with a hot CPU. I wouldn’t want to run this mod with full cpu usage 24/7. I plan to do this mod myself later this month and I’ll definitely be attaching some heat sinks. Quote Link to post Share on other sites
johnklos Posted November 30, 2020 Report Share Posted November 30, 2020 On 4/25/2020 at 1:14 PM, mac512 said: Would it be too much for the 25MHz CPU in the long run? No. The CPUs marked 33 MHz are made exactly the same as the ones marked 25 MHz. Also, they generate so little heat that you'll never have issues. Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.