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Carrera040 cloning


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Speaking of which, is there an authoritative guide to finding legit CPUs - esp the 68040 non-LC 40mhz ones? Did I see once that they no longer make them hence it’s about finding old ones and avoiding fakes/screen printed variants that are slower or actually LC chipsets?

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Oh that's very, VERY nice Bolle. you always find ways to out-do yourself with yet another amazing example to reverse engineering. I don't know how you do it!

 

Definitely still up for a Cache add-on for my Carrera that's sitting in my IIci.

 

To be honest, money-no-object, I'd really love another complete set to put in my IIvx, but really that would probably be a bit wasted in that and would be nothing more then morbid fun to see the lackluster results.

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5 hours ago, demik said:

How does this fit an Iicx ? Do you need another extra board ?

This post shows the MicroMac IIcx adapter for the Carrera :) Might be a bit of unobtanium these days...

 

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13 hours ago, Bolle said:

I am using a MC88916DW80 which is rated at  a maximum of 40/80MHz for the B- and P-clock respectively.

The exact same clock generator (although at a lower speed rating) is also found on some Macintosh logicboards.

I have seen Turbo040s with 35/70MHz and lower 25/50MHz rating as well. All Carreras I have seen so far have used the 40/80MHz version.

 

Well, if you find a use for the slower ones, I have a reel of 998 of the MC88916DW55...

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19 hours ago, demik said:

Thanks ! Looks only simple traces to create a PDS slot.

 

Should be straightforward to replicate

I can provide the schematics of the Micromac IIcx adapter if you want. Got one of those as well.

Also mind you will need the more uncommon socketed IIcx logicboard unless you are ready to desolder the CPU on your logicboard and put a socket in place.

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6 hours ago, Bolle said:

I can provide the schematics of the Micromac IIcx adapter if you want. Got one of those as well.

Also mind you will need the more uncommon socketed IIcx logicboard unless you are ready to desolder the CPU on your logicboard and put a socket in place.

 

Thanks ! I got two IIcx, one socketed, one soldered. The socketed one isn't starting yet (recap done), Don't want to mess with the working one, I will keep your offer in mind.

 

Good job anyway !

Edited by demik
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Also for bragging rights:

 

IMG_5778.thumb.jpg.e2b23a794f6350e04b828f61f3d04975.jpg

 

No external cache though at that speed, so you're still slower than a 40MHz 040 with 128k external cache.

Benchmark speed of the cacheless 50MHz 040 in a SE/30 is in the range of a 50MHz 030 with external cache.

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  • Gorgonops changed the title to Carrera040 cloning
  • 2 weeks later...
On 1/8/2021 at 8:43 AM, Kai Robinson said:

@TimHD I use UTSource - plenty of L88M mask Freescale 040's there for about $59 each. 

 

Well... the "L88M"s I got from utsource were reprinted. The mask they printed on there was made up and a 2012 datecode also doesn't make too much sense:

 

7jw3B0l.jpg

 

 

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Its sad that these companies have to fake stuff like that. I can’t really see much reward for them doing it either. 90% of people using vintage stuff will know it’s fake. Unless this fake was made 20-25 years ago. 

Edited by maceffects
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4 hours ago, Bolle said:

Well... the "L88M"s I got from utsource were reprinted. The mask they printed on there was made up and a 2012 datecode also doesn't make too much sense:

 

I had the same experience with them last week. They refunded me at least.

Edited by pax
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The ones I got do have a FPU, so they are some kind of full 040.

They also don’t seem to run as hot as most of the other chips I have around but they’re far from being what I would consider cold running.

They are rock solid at 40MHz though and at least one of them also seems to take 50MHz just fine as well.

 

Still trying to see if they’re going to refund me because there’s obviously some faking going on here even if the prices weren’t actually too bad even for what I got considering they run fine at 40MHz.

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Mine is also a full 040. No idea how they source these chips and where in the supply chain the faking is happening. I sent them a screenshot of the original listing and said that the item I received was incorrect and runs too hot for my purposes. I received a full refund and they did not ask me to return it. I never called it out as a fake, I just said it was the wrong mask, which they didn't argue with.

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On 2/1/2021 at 11:02 AM, Bolle said:

 

Well... the "L88M"s I got from utsource were reprinted. The mask they printed on there was made up and a 2012 datecode also doesn't make too much sense:

 

7jw3B0l.jpg

 

 


UTSource will refund you for that - definitely. They actually want to have a decent reputation. Raise a dispute already?

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4 hours ago, Kai Robinson said:

Raise a dispute already?

 

I did, they're working on it.

That said, everything else I got with that order was perfect.

Edited by Bolle
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