LC 475 modification
The other day, I got a lot
of Macs for
After some investigation I soon decided the LC 475 was the most fun
machine I had gotten and I started looking for information. Soon I
discovered that, if I wanted any Unix-a-like on it, I needed a 'real'
68040. Well, after putting some rumour to the fact I wanted this CPU, I
eventually was able to get one. And of course, then I needed to get this
all going, of which you can see the result here ;-)
...here you can see everything that it takes to take the LC from 25 mhz
to 33 mhz...
There was a resistor of 300 Ohms on R25 and a
resistor of 4.7k Ohms on R21. I changed it, so now the 300 Ohms resistor
is on R22 and the 4.7k Ohms is on R24... That's all!
...here you can see both CPU's, the sluggish 25 MHz 68LC040 and the
speedier 33 MHz 'real' 68040...
...heatsinks meant for the Pentium I do fit quite well on a 68040...
...MacOS is still there for testing purposes...
...after the first testrun I decided to put a fan on the heatsink as well
as it is running quite hot, and I didn't even overclock this baby!...
On this picture you can also see it in it's final form, with the
ethernet-card, I only need a bigger SIMM in there(this is a 16mb stick).
By the way, I also turned the main fan around, cooling is much better if
air is sucked out of the case instead of blown in...
...this must be the first machine I own *without* Duct Tape on the
...sometimes machines have identity-crises, but my LC is starting to
is a Workgroup Server 95... :-)
Well, because everything is going so well with this project, I've gotten
...a few days later...
It did *attempt* to load the A/UX-CD... Really! I swear! Uhm, just once...
I keep continuing...
...and again a few days later...
...I decided to put NetBSD on the Mac first and this seems to work!
(c) 2003 Mark