68040 plastic case from Freescale to pin configuration?

[pizzigri]

Hi!
So, I am seeing a LOT of ebay sellers offering a plastic package, QFP, 33MHz 68040 from Freescale or Motorola at ridicolous prices (like this one: 68040 cpu) and I was wondering, are they real/fake? Are they compatible with a standard 68K?
...and if they are, how difficult / expensive would it be to make an adapter for PGA?

 

[Bolle]

Those are 68040V… they run on 3.3V instead of 5V.
Also they don’t have a FPU like a 68LC040.

To adapt them to a standard 040 PGA socket in a Mac you’d have to design an adapter that implements a voltage regulator to step down 5V to 3.3V but you’ll still end up with a chip without FPU.
Not worth it if you ask me.

 

[pizzigri]

Hey Bolle,
that’s really too bad.... a regulator (a la’ Intel Ovedrive ) wouldn’t have been a problem I think, but missing the FPU you are right.... argh

 

[Paralel]

This reference from NXP should tell you everything you need to know about the 68040 series as of Rev 2.3:

https://www.nxp.com/docs/en/reference-manual/MC68040UM.pdf

Unfortunately, I don't know of any more recent revision, as even Rev. 2.3 is quite old.

 

[Daniël]

QFP 486 and 386 CPUs adapted to PGA weren't uncommon back in the day, so such a thing could be done for the 68040. However, taking a look around, I think it's going to be difficult to find legitimate parts. Most "68040FExxA" and such sellers either don't show the chip, or show one with the mask revision of 3F54F, which seems to correlate with the FPU-less, 3.3V version as discussed above. Lots and lots of fake chip scammers seem to be fond of the 040 and 060 CPUs, precisely because they're hard to get, expensive and sought after, so their slightly more affordable ones seem like a good deal, but it's all the same fake crap.

 

[Paralel]

QFP 486 and 386 CPUs adapted to PGA weren't uncommon back in the day, so such a thing could be done for the 68040. However, taking a look around, I think it's going to be difficult to find legitimate parts. Most "68040FExxA" and such sellers either don't show the chip, or show one with the mask revision of 3F54F, which seems to correlate with the FPU-less, 3.3V version as discussed above. Lots and lots of fake chip scammers seem to be fond of the 040 and 060 CPUs, precisely because they're hard to get, expensive and sought after, so their slightly more affordable ones seem like a good deal, but it's all the same fake crap.

I would agree with making sure the mask matches one that was actually used for the part one is looking for. That info should be available on the NXP site.

I would also say to not discount the XC parts. The Powerbook 550c used the XC68040FE33M and worked just fine. I've never been able to figure out why that part ended in an M though, very unusual for a Motorola part.

 

[Daniël]

I would agree with making sure the mask matches one that was actually used for the part one is looking for. That info should be available on the NXP site.

I would also say to not discount the XC parts. The Powerbook 550c used the XC68040FE33M and worked just fine. I've never been able to figure out why that part ended in an M though, very unusual for a Motorola part.

I did check for those parts as well, but still only found few listings, with either no pictures, or once again of pictures of the supposed chips, with the 3F54F mask revision.

I think what doesn't help, is that the 68040 seems to still be in demand for certain specialized embedded solutions by companies with deeper pockets than us mere hobbyists. Rochester Electronics, who currently produce new 040s, detailed late last year that they were making new ones for a client needing them for the production of medical ventilators, for example.

 

[Phipli]

I did check for those parts as well, but still only found few listings, with either no pictures, or once again of pictures of the supposed chips, with the 3F54F mask revision.

I think what doesn't help, is that the 68040 seems to still be in demand for certain specialized embedded solutions by companies with deeper pockets than us mere hobbyists. Rochester Electronics, who currently produce new 040s, detailed late last year that they were making new ones for a client needing them for the production of medical ventilators, for example.

The 68k chips were used for military applications too.

Regarding masks, be aware that sometimes different chip types (full, vs. LC) can have the same mask, but the FPU has been disabled.

I have some LC chips that have a mask that was also used for full chips and these are original chips from macs. I assume that they might be chips that when they were tested, had a fault in the FPU and motorola lasered out a link to disable the FPU. Or something.

 

[Daniël]

Regarding masks, be aware that sometimes different chip types (full, vs. LC) can have the same mask, but the FPU has been disabled.

Very true, but some of the notably fake ones reported on, such as the poor chap trying to upgrade his PB520c only to have the newly soldered in CPU not have an FPU either, had that mask revision. So I wouldn't be surprised if it's at least indicative of having a high chance of being FPU-less.