66mhz 060's

[MuLTiViEW]

 keropi:   That is confusing then with the 060.  I admit Im not quite as familiar with the 060 as some of the others.  CPU world didnt seem to have them all listed either.

 

Nope, you're getting addressing/data mixed up..the ec020 has 24bit external addressing, it still has the full 32bit data bus.

Motorola 68EC020
From Wikipedia, the free encyclopedia.

The 68EC020 is a microprocessor from Motorola. It is a lower cost version of the Motorola 68020, the difference between the two being that the 68EC020 only has a 24-bit address bus, rather than the 32-bit address bus of the full 68020, and thus is only able to address 16MB of RAM.

The 68EC020 was used as the CPU of the Amiga 1200.

 32 bit input, like the 68000
 & 24 bit ouput.

 
 
 As for the discussion of using other FPU in other CPU's over the 68060.  I was on the wave length of a discussion earlier reguarding the 060's "poor pipelining" routines for it's internal FPU.
 So some of those solutions are probably not realisticly obtainable unless there is involved a design which would do this.
 I've been discussing some over the top ideas with people elsewhere on that very matter, and dumbly didn't include the 3 hour chat log of the details leading up to that.  Sorry.

 Interesting however, this thread is.  I would like to know where people are buying 060's at these days. Seems everyone has a different source here and there.

 Also, I would REALLY like to know from the people viewing this topic, how they each cool their 060's.  I mean specificly.  What types of fans and whether or not they used thermal tape or a thermal paste.  
 I've been viewing lots of pages here and there and would like to know what people here do to keep things cool

[shoggoth]

I've seen rev. 6 (mask 71E41J) '060:s running as fast as 100Mhz in the Atari Falcon using a normal fan.

My 060 (full version, but labelled as EC, mask 01F43G) runs at to 72Mhz without problems. 80Mhz caused cache problems. I use a normal 486-type fan.

Seems like some 060s can run at twice their rated clockspeed, and some can't.

-- PeP

[shoggoth]

Forgot to mention; I use thermal tape (the white kind) to attach the heatsink to my 060.

-- PeP

[MuLTiViEW]

 I've noticed a lot more people using thermal tape as opposed to the paste.

 Any reason why it's better?  Maybe a better consistancy?

[shoggoth]

Tape can be used to attach the heatsink to the CPU.
Paste can't, but is probably better.

-- PeP (well, a.k.a. Shoggoth apparently)

[MskoDestny]

There's always thermal adhesive.  It's probably the best compromise between the two.

[Doobrey]

MuLTiViEW wrote:
 32 bit input, like the 68000
 & 24 bit ouput.

Huh? sorry but that is not what the Wikipedia article, myself or Piru said.
Maybe it's a language problem, maybe it's your cold medicine.. ;-)

[MuLTiViEW]

  Doobrey , maybe the problem of language is at your end.
  Or perhaps we've both misunderstood one another?
 
 

[shoggoth]

I don't really get your post here. I hope I am not offending you with my comments, I can assure you that this is not my intention.

The FPU in the 060 is (insanly much) faster than the 68881/68882. A few FPU instructions are missing, but this can easily be handled with very little slowdown.

> But I was planning on using a simple "LC040" + the 882.
> Something like 40 mhz 040 and a 50mhz 68882.

You can't use a 68881/68882 with a 040 or a 060. Well, you could use it in memorymapped mode, but that's not much point since it is very very slow. Even if you could use in co-processor mode (which you can't), it is so much slower than the built in FPU.

>Most of the 060's made, all the 50mhz versions seem to have
>the FPU, while more 66mhz versions and 75mhz versions DONT
>seem to have the FPU. At least the "available" ones dont.

Rev 6 (mask 1E41J) is marked as 50Mhz, but runs quite happily at 80,90 or even 100Mhz. It has a built in FPU.

> Remake your own 060 card, and use either a PPC's FPU,
> or a coldfire's internal FPU.

You can't use a PPC or coldfire as an FPU for the 060. You can use them as separate CPU's, but they won't execute FPU instructions for the 060.

> Remake the card, put a socket for a 68882 @50mhz in and
> try and find one of the latest revisions. Overclock that
> thing to 75 mhz or even 100mhz. Supposedly, and this is a
> BIG SUPPOSEDLY, they really did make 100mhz 882's and
> stamped them with "50"

... or use a 060, because it will usually be faster even if you run it at a lower frequency.

If you're serious about this, I suggest you do something similar to the CT60 accellerator for the Atari Falcon. It uses SDRAM, allowing it to operate at 100Mhz (provided that you have a Rev. 6 060).

Or, use a Coldfire, but there are quite a few differences between the 68k and the coldfire, which might cause a lot of compatibility problems (=the software effort needed is quite big).

Sorry for comparing your post to an old hoax on the Atariscene. I'm a bit triggerhappy, I guess.

Also, sorry for posting info about Ataristuff in this forum, but I thought it was relevant in this case. I am planning to get my first Amiga soon, since I want to see this side of life too.

-- PeP

[MuLTiViEW]

>Most of the 060's made, all the 50mhz versions seem to have
>the FPU, while more 66mhz versions and 75mhz versions DONT
>seem to have the FPU. At least the "available" ones dont.

Rev 6 (mask 1E41J) is marked as 50Mhz, but runs quite happily at 80,90 or even 100Mhz. It has a built in FPU.

 The site I was looking at seemed only to sell the fpu-less variety of 060.  My bad for not explaining. There was also a mis-understanding on my part on the "EC" labeling here.

 

> But I was planning on using a simple "LC040" + the 882.
> Something like 40 mhz 040 and a 50mhz 68882.

You can't use a 68881/68882 with a 040 or a 060. Well, you could use it in memorymapped mode, but that's not much point since it is very very slow. Even if you could use in co-processor mode (which you can't), it is so much slower than the built in FPU.

 I don't want to get into an argument on this, so I'll simply say this.  I was "brainstorming out some ideas"  which I had based on a pair of articles I had read either online or from a book.
 One of the articles exclusively explains....   well it's titled:  68040+68882    apparently some early form of accelerators actually used those two chips together.
 But as I tried in vain to find the article and came up short.....
 
 !

 On the other note, I was comparing the idea to using a NON FPU version of the 040 (and possibly the 060 which I am less familiar with).

 Primarily,   the 68  LC  040    which is an "fpu-less"  CPU

 Many of the software I have come across personally has 882 code,  and thus going by another written article, I'm told the 040 has to work harder to process this 882 code. (it reverts to software libraries to process the code.  the slow down hence is what I was focusing on)

 An aquaintance of mine from New Zealand had this to say upon my asking in relation to your comment....

you would just patch the OS to use the extern FPU ...
any hardcoded direct usage within a program would vector to the illegal intruction TrapCall and be vectored to the FPU as well
so technically patching any FPU usage from the CPU at all would revector to the extern FPU
and as the 882 runs Asynch from the CPU you would be able to run a triple-pipeline of operations as long as the FPU ops dont get out of sync to the MCU ops
actually the 040 and 060 keep the cp protocol
they simply dont go external for the internal mapped logic IDs
you CAN use upto 4 external FPUs without problem if you really want
you have to map them as "extra" cps

 In any event, I was only testing the waters of some ideas out, and don't claim to be an 060 expert by a long shot.

[MuLTiViEW]

 One more tidbit of info.  

 The thing that led me thinking about the coldfire - fpu  -wave of thought....

 HERE

 Scan the summary to the 7th item and you'll see...

 

# Floating point unit (FPU)

   * Double-precision implementation of the MC68060 FP ISA
    * Concurrent execution between Operand Execution Pipeline & FPU
    * IEEE-754 compliant

 I couldn't help but to let my imagination get the better of me

[Doobrey]

MuLTiViEW wrote:
 I don't want to get into an argument on this, so I'll simply say this.  I was "brainstorming out some ideas"  which I had based on a pair of articles I had read either online or from a book.

Nothing wrong with brainstorming, you never know what problems or solutions other people will chuck in that you never thought of.

  Many of the software I have come across personally has 882 code,  and thus going by another written article, I'm told the 040 has to work harder to process this 882 code. (it reverts to software libraries to process the code.  the slow down hence is what I was focusing on)

Not all FPU code, only the instructions that Motorola cut out on the 040/060 should cause a slowdown as it has to be handled by the trap code you mentioned.

Dunno if this is one of the articles you read ,ImprovingPerformance, there's a good section on FPUs and maths libraries at the top.

[shoggoth]

Hi there,

> I don't want to get into an argument on this, so I'll
> simply say this. I was "brainstorming out some ideas"
> which I had based on a pair of articles I had read either
> online or from a book.

Well, I understand that you're brainstorming. My intention is to contribute to your project, whatever it may be, by giving you some hints & tips.

>One of the articles exclusively explains.... well it's >titled: 68040+68882 apparently some early form of >accelerators actually used those two chips together.
>But as I tried in vain to find the article and came up >short.....

As I said, you can use a 68882 in memory mapped mode, but not in coprocessor mode. If you code in assembly language, which I suspect you don't (judging by your previous posts, my appologies if I'm wrong), you know that accessing an FPU in memorymapped mode is very slow.

>Many of the software I have come across personally has 882 >code, and thus going by another written article, I'm told >the 040 has to work harder to process this 882 code. (it >reverts to software libraries to process the code. the slow >down hence is what I was focusing on)

Unimplemented instructions has to be emulated using other instructions. While this adds some overhead, this is not necessarily slower.

When designing the 040, Motorola studied how FPU instructions where used & choose to implement any instruction that made up more than 1% of the FPU code base.
This means that the missing instructions are used (very) rarely, and thus the emulation of those instructions causes very little overhead.

>An aquaintance of mine from New Zealand had this to say
>upon my asking in relation to your comment....
you would just patch the OS to use the extern FPU ...
any hardcoded direct usage within a program would vector to the illegal intruction TrapCall and be vectored to the FPU as well
so technically patching any FPU usage from the CPU at all would revector to the extern FPU

Yeah, of course you can do that. This is how missing FPU instructions are handled on a 040/060, except that in your case you will have to do it on _every_ FPU instruction (which would definitely slow things down to a crawl).

and as the 882 runs Asynch from the CPU you would be able to run a triple-pipeline of operations as long as the FPU ops dont get out of sync to the MCU ops
actually the 040 and 060 keep the cp protocol
they simply dont go external for the internal mapped logic IDs
you CAN use upto 4 external FPUs without problem if you really want
you have to map them as "extra" cps

This is not entirely true. For example, FPU 2, 3, 4 has no idea of the register context of FPU 1 (and vice versa). This is not a problem if the code takes this into account, but unfortunately this is not the case since noone expects more than 1 FPU in the system. There is no workaround for that.

Also, I think the dude is referring to the coprocessor protocol of the 020 & 030, rather than the 040 & 060, since what he describes simply isn't possible on these CPUs (unless the FPUs are memory mapped, which is ... well... stupid, in that case).

Furthermore, the FPU in the 040 & 060 runs in parallel with the integer unit. This means that while the FPU is busy calculating stuff, the CPU can carry on with other stuff (provided that you organise your code properly - which people do).

>In any event, I was only testing the waters of some ideas
>out, and don't claim to be an 060 expert by a long shot.

Yep, and as I said I am just helping you to get on the right track. Wouldn't want you spending lots of time designing stuff that won't work!

regards & good luck

-- PeP

[MuLTiViEW]

 Okay, thanks from both of you on that note.  

 Doobrey that is a good page.   Yet another page "bookmarked" for future reference by the donkey  

 I think we better actually stop here, because Ive noticed we are dangerously close (if not already) hijacking a thread.

 Heheh

 But the info is good and I understand some things a bit better anyways.  I really do want to make some boards of my very own, and if I do any, they will probably be for Classic Amigas.  
 I think all Amigans and maybe even some of those Atari users should definitely dabble into designing their own expansion cards.
 Whether or not they intend to sell anything at all, it shouldn't matter.  The Amiga's growth I believe was well stunted, it has some catching up to do and sometimes you have to go backwards before you can go forwards.
 But that is another topic that should be discussed on maybe my own thread.  

 Heh.. sorry zx6r6 .   I really didn't intend on doing any hijacking.  
 I hope they dont start searching me before I get on board a new thread .....    :-P