LC 475 Project - Upgrades - Mods

killvore

Well-known member
This is very inspiring! I'm considering the 33MHz upgrade, but need to build up some confidence in my soldering skills first 😅

I use System 7.1 on my LC 475 with a couple of extensions to get 7.5ish levels of compatibility with some of the software I use (DragThing, Transmit, etc.) - plus the appropriate System Enabler ofc. I find it to be fast, stable, and uses little RAM (<2MB iirc - I've set the cache to be pretty beefy so can't check exact size now). Also, I have an irrational hate of the 7.5.x "Apple Guide" menubar icon 😄

Extensions
Macintosh Drag and Drop, Dragging Enabler, Thread Manager 2.1, all the Open Transport stuff, the Finder Scripting Extension, and Apple Event Manager (but can't remember if these came with the system or not). You could also add the Appearance Manager!

Control Panels
SetDate, MacTCP, PC Exchange, Power Windows (to show off your extra processor cycles), and SuperClock
 

Kamshaft

Active member
This is very inspiring! I'm considering the 33MHz upgrade, but need to build up some confidence in my soldering skills first 😅

My soldering skills are not "professional", but I get by. If I were to recommend two things... Good tweezers and buying a hot air rework station (350 degrees Celsius) would have helped me with removing and resoldering those tiny resistors (size of a grain of sand!). :ROFLMAO: You don't want one of those flying away...


Otherwise, add lots of flux, and fresh solder, and then remove the solder with copper desoldering braid.
 
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Powerbase

Well-known member
This is very inspiring! I'm considering the 33MHz upgrade, but need to build up some confidence in my soldering skills first 😅

I use System 7.1 on my LC 475 with a couple of extensions to get 7.5ish levels of compatibility with some of the software I use (DragThing, Transmit, etc.) - plus the appropriate System Enabler ofc. I find it to be fast, stable, and uses little RAM (<2MB iirc - I've set the cache to be pretty beefy so can't check exact size now). Also, I have an irrational hate of the 7.5.x "Apple Guide" menubar icon 😄

Extensions
Macintosh Drag and Drop, Dragging Enabler, Thread Manager 2.1, all the Open Transport stuff, the Finder Scripting Extension, and Apple Event Manager (but can't remember if these came with the system or not). You could also add the Appearance Manager!

Control Panels
SetDate, MacTCP, PC Exchange, Power Windows (to show off your extra processor cycles), and SuperClock

My soldering skills are beginner-level and I managed, even with a bobo battery-powered soldering iron. They are tiny though. I was a bit more bold. Just take your time.

Completely forgot about Powerwindows, I even used to use it back in the day.
 

lmartu

Well-known member
@Kamshaft you will never get the lid closed. Get a small radial fan and place it bedside the heatsink somewhere on the MB. so that it blows air on the fins from the output duct.
You can keep it still with four little blobs of Blu Tack. That's what I did
 

Daniël

Well-known member
How about RAM Chips?
Is there a voltage regulator on the back side of the Module?

Keystron knowingly runs RAM chips out of spec, with their reasoning being that "they've never seen any issues from doing so". What's worse, is that on their 30 pin SIMMs, they put the specification sticker across the memory ICs, covering the parts number. What makes it particularly damning, is that the sticker is marked as "warranty void if removed", which next to breaking Magnuson-Moss, means you couldn't check if the chips are running out of spec without breaking said warranty.
 

finkmac

NORTHERN TELECOM
huh, wouldn't that restrict airflow to the rest of the board? I guess the other components don't exactly have a directed fan so it would be the same amount of air going through the case...
 

zigzagjoe

Well-known member
With the duct, It's probably "fine" for system cooling but it's likely louder than the stock fan already is due to airflow obstruction/interference.

I personally changed my Q605 system fan out for this extremely quiet fan Sunon I'd salvaged out of a set-top box some time ago: HA60251V4-000U-999

1732130817093.jpeg
The fan tabs are broken on mine so I didn't particularly mind that it is thicker than the original 15mm thick fan. Actually, due to that it ends up moving more air through the system despite being a low noise fan. You could likely do the same using a Noctua fan as long as it's 25mm thick - don't like-for-like replace vintage fans with Noctua.

In conjunction with the sunon fan I found this heatsink provided sufficient cooling at 40mhz.
43.1 X 43.1 X 16mm: https://www.digikey.com/en/products/detail/same-sky-formerly-cui-devices/HSB27-434316/16562708

You might also consider using a HSF (heatsink-fan) instead on the CPU. Here are some low profile options I've looked at. Any of these are fine for a 68040.

35x35x10mm: FIT0504 5V https://www.ebay.com/itm/154634399662
40x40x8mm: AP0405MX 5V https://www.ebay.com/itm/284895799440
41x41x12mm: VC-AL4009 12V https://www.ebay.com/itm/144558738482
45x45x10mm: AP4505MX 5V https://www.ebay.com/itm/134203475332
45x45x10mm: AP4512MX 12V

12V ones will generally run slow and quiet on 5V. Alternatively, a resistor can be used to slow the speed of the 5V rated fans. The larger system fan will hide the noise of these easily. Even with the Sunon fan (above) I don't find the noise of the FIT0504 at full speed noticable or objectionable and still far quieter than the original fan.

FIT0504 installed on a QFP 68040.
1732130309507.jpeg

AP4505MX on a PGA 68040, 45mhz with a speed reducing resistor (don't recall the value).
1732130479665.png
 

eharmon

Well-known member
I should grab a picture, but my 040 has a standard early Quadra-style heat sink (vertical fins, not a crown), with a Noctua NF-A4x10 FLX on top. Those 40x40 fans happen to align their holes such that you can basically screw right into the heat sink...they fit between two rows of fins and it hangs on nicely. Fins bend a tiny bit and get threading scoring, but it's a nice solution.
 

register

Well-known member
I don't remember seeing that option, except on a few macs here and there. I've always heard that you couldn't disable it, due to it being embedded in the rom (hench the upgraded ROM being able to disable it).
I used to have an LC 475 with 132MB of RAM. This was the solution to get rid of the annoying boot delay. It also works in a beige PowerMac G3 that hits the RAM ceiling.
 
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