Succesful LC III upgrade!!

4 posts / 0 new
Last post
iamdigitalman's picture
Offline
Last seen: 1 year 8 months ago
Joined: Mar 1 2004 - 22:18
Posts: 629
Succesful LC III upgrade!!

It's offical, I just speed bumped my LC III from 25mhz to a blazing 33mhz. I did so by switching resistor R14 into the blank R74 on the undercarrage. I re hooked up, booted, bong, load, and then I ran Apple Personal Diagnostics (want it? PM me.) although, it now is called a Performa 406 in APD rather than the Mac LC III like before. I wish I could bump it to an 040 processor. is there a way? I think I saw one at the end of the service manual (googled for it). also, the mobo is a Revision D, but it says (c) 1992. why? oh, almost forgot teh specs:

Macintosh LC III
Motorola 68030 '68LC30' @ 33mhz
36mb ram
standard VRAM (I want more!! )
250gb conner HD 50 Pin SCSI inside
original 80mb Quantim 50 Pin SCSI outside (I have it in a hand build LEGO chassis) (the next compubrick accesory?)
Daynaport 10T ethernet PDS card
System 7.5.5 Revision 2

btw, I will post pics as soon as I can afford a digi cam.

P.S. the ethernet connection is odd. I can use PCMAC LAN to transfer files to it, but cannot connect to internet via same connection and iCab. why? I use a wireless hub, and have SBC Yahoo DSL with a 2Wire brand DSL modem. lemmie know about this one.

-digital Wink

tmtomh's picture
Offline
Last seen: 1 year 7 months ago
Joined: Dec 20 2003 - 10:38
Posts: 568
Nice!

Nice OC job.

The easy -- and only -- way to bump it to an '040 is to swap in an LC475 (or Performa 475/476, or Quadra 605) motherboard, which will fit perfectly and give you a 25MHz 040 CPU.

Then you have to OC that motherboard to get back to 33MHz.

Matt

Offline
Last seen: 17 years 6 months ago
Joined: Dec 26 2003 - 16:21
Posts: 584
hmm

But then, wouldn't the 25MHz '040 kick the living snot out of a 33MHz '030? I may be wrong... but I think if he did that overclocking it would have no real point...

tmtomh's picture
Offline
Last seen: 1 year 7 months ago
Joined: Dec 20 2003 - 10:38
Posts: 568
Yes and Not Necessarily

A 25MHz '040 would indeed leave a 33MHz '030 snotless Wink -- but one might still want to overclock the '040 motherboard. Going from 25MHz to 33MHz gives about a 30 percent increase in raw CPU speed, which might be worthwhile for some folks. Also, some folks just want to have an OC'd board, esp. here on 'fritter.

Matt

Log in or register to post comments