Where to get a full 040 CPU for PowerBook Duo?

. . . check out his old posts over at the old 68kMLA archive. IIRC, he added a full 040 to the processor card in his 5XX to run some version of 'NIX/Linux.

jt

I have a PB 540 that I want to add a full 040 to. The main problem is finding the little buggers. Arrow electronics had them but wanted $200 a piece. I found one place that would sell them for $5 but had a minimum 100 piece line order.

Here is my tread at the old 68kmla about it.
http://www.literatureclassics.com/68kmla/topic.asp?TOPIC_ID=4405

We are having database problems with the archives so all you can access is my original post. But it does get you the part number MC68040FE25A

Good luck and be sure to let us know if you ever find any of the chips.

Hi redrouteone-
We spoke about this on 68kMLA a year ago. I'd like to read about Alien's exploits, but the archives at literatureclassics aren't working for me.

Now that I am working again, I'd be down for starting a pool for a MC68040FE25A purchase! Don't know how easy it'll be to scare up more buyers though. I will easily commit to 10 pieces. Uneasily... a tentative 20 pieces, but no more, until I get rich. Attention all 68k hackers!

Wow, I see how much interest there is here! (rolls eyes)

Lackof replies is not always a lack of interest, could be just a lack of further input to the situation. I'd sure like a full '040 for one of my 280s, but it's fairly low on the to-hack list ATM.

I have three working chips salvaged from otherwise dead Quadra/Centris machines. One is the full 68040 and two are the 68040LC chip.

If someone here wants any of them for their legacy machines, contact me.

Humm I don't use the PB540 much any more but I would love to try it just to say that I have done it.

See what price you can get them for and let us know. I did just send off a couple of requests for quotes so we can see what happens.

Humm I don't use the PB540 much any more but I would love to try it just to say that I have done it.

See what price you can get them for and let us know. I did just send off a couple of requests for quotes so we can see what happens.

The cost of shipping will be the dominant cost element.

On edit... I am assuming that whoever is looking for this CPU chip intends to use it on a machine with a socketed chip, where one can just pull the 68LC040 out of the socket and drop in the 68040 chip.

If you are talking about a chip that is soldered directly to the motherboard, I can't see a hobbyist doing this with a soldering pencil and expecting to pull it off.

I've swapped these chips on my Quadra/Centris motherboards with ease, but that's because they are socketed and there is plenty of breathing room to dissipate the heat, either way.

On the other hand, the 68040 runs at 25 MHz, but the 68LC040 runs at 20 MHz, so the clock on the motherboard governs the actual speed of operation. If the motherboard has a 20 MHz clock, the CPU will operate at that speed, even if it could reliably run faster.

So the main advantage is the builtin FPU on the 68040.

First of all, Why? I understand obsession, so I'll let that one go for now ... the main reason none of the PowerBooks have a full 68040 is heat. They are all designed around the 680lc40 to keep 'em cool. Assuming you could figure out how to do this (and that is a big if as you need to be MORE than proficient with a soldering iron to swap a machine soldered CPU on a semi-modern Mac), you'll need to address the heat issue or you'll fry all your hard work. I'm not even sure the chip's pins would line up with the existing leads on the logic board, much less if the ROM would know what to do with it. Now we're back to the "why" -- what's actually missing from a full blown 68040? The FPU is the main thing and that can be easily provided for by "Software FPU". It's what I had to use with my Duo 280c because for some reason, even though the Duo Dock had an FPU on board, it could only be used with the 68020 & 30 (That's Apple for ya!). If you manage to do it, my hat's off to you! But it will certainly be one hell-of-a-hack! If you are planning all this work anyway, why not just buy an old Centris or Quadra and strip its chip to squeeze in the box?

First of all, Why? I understand obsession, so I'll let that one go for now ... the main reason none of the PowerBooks have a full 68040 is heat. They are all designed around the 680lc40 to keep 'em cool. Assuming you could figure out how to do this (and that is a big if as you need to be MORE than proficient with a soldering iron to swap a machine soldered CPU on a semi-modern Mac), you'll need to address the heat issue or you'll fry all your hard work. I'm not even sure the chip's pins would line up with the existing leads on the logic board, much less if the ROM would know what to do with it. Now we're back to the "why" -- what's actually missing from a full blown 68040? The FPU is the main thing and that can be easily provided for by "Software FPU". It's what I had to use with my Duo 280c because for some reason, even though the Duo Dock had an FPU on board, it could only be used with the 68020 & 30 (That's Apple for ya!). If you manage to do it, my hat's off to you! But it will certainly be one hell-of-a-hack! If you are planning all this work anyway, why not just buy an old Centris or Quadra and strip its chip to squeeze in the box?

The chip is not socketed it is a surface mount. The CPU module is removable from the system so it makes it easier to work with.

I have been experimenting with a paint stripper to do hot air reflow. I have had luck with removing components and having them still work. I need to practice with re-soldering some more but it should work.

Both versions are pin compatible.

As far as heat I am not very concerned about it. If it does become a problem nothing that a 20 mm fan won't fix.

As far as why. I want to run some version of Unix on mine.

There are releases of NetBSD/mac68k that are compiled to support FPU-less machines. The most current release is linked here.

This needs to be a surface-mount version, there is no socket on the PowerBook CPU cards, and probably no room for one. Also, I think there might be different voltages, but I'd need to look it up to be sure. Often, the SMT versions of CPUs will runn off of 3.3 volts for portable applications, whereas the socketed ones have traditionally been 5v. I don't mind spending an afternoon getting the mounting right, I can do tight soldering.

Heat certainly can be an issue, but it can be addressed. Make a better heatsink. Install a fan in an expansion bay. There are many ways to cool a laptop.

Why a full 040? I need a FPU. Not just to fool an OS into letting me install it, but to crunch floating point numbers. I do want to try 68k UNIX versions on there, but my main use is for running older audio and MIDI software. The audio software often does things like fourier analysis and basic DSP, so needs a FPU. The MIDI apps are very real-time, so getting any floating-point tasks running in hardware rather than emulation will improve performance.

What amazes me is that there were SO MANY cards and machines out there which used this vintage of 68k CPU, but I can't even find ONE of them. This is a very common chip. I prefer to recycle old technology rather than buy new, especially when the price difference is this great. Too bad there is not a table of what 68k devices used these chips versus other 040 formats. I look on eBay but people never mention the specifics, and just do mile-high aerial shots of their peripheral cards so I can't see what's on there. Somewhere out there is an old Amiga accelerator or router or something with the CPU I need, I just need to find it!
M

The problem with some old Amiga chips and many embedded apps is that they might be using the 68EC040. That is the one with no MMU. No MMU is worse than having no FPU. The MMU is what lets you use Virtual Memory and makes multitasking much better. Don't get suckered into a cheap 68EC040 without looking it up first.

Hi all,

I also want to buy a full 68040. Even though the oscillator on my Quadra 605 is makes this machine run at 20 MHz, I would sincerely want to commit on buying an 1 piece running at 40 MHz.

Please let me know if you have any news on that!

TIA

You need a different part than what we are looking for. Your 605 uses a socketed chip as opposed to the surface mount chip that we need.

Socket 68040s are very easy to find. A search on ebay for 68040 usually turns up a bunch.

Hi guys,

I my search for a full '040 to replace my LC chip I came across this board that might be of interest:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4598&item=5203523638&rd=1&ssPageName=WDVW

Its is supposed to be an accelerator for the Amigas A2000 or A500. By the look on the picture, I don't see the processor and it's not soldered to the board or not. But it's worth to ask the seller, right?

Cheers!

Nope, sorry, the SUPRA 28 is a 28MHz 68000 card. You are gonna have a hard time finding a good 68040 card for an Amiga for a good price, if the Amiga upgrade market still has any steam. Again, be wary of 68EC040 CPUs. Ask myself or Dr. Bob (both of us are admitted Amigans of back in the day) if you are unsure if a card had a certain CPU. One of us should be able to point you in the right direction for info.