On Mon, 23 Aug 2004 23:45:18 +0200, Peter Graf wrote:

> On 23 Aug 2004 at 15:22, Thierry Godefroy wrote:
>  > I'm quite upset !...
>  >
>  > I just discovered that my Q60 was fitted with a buggy 68060 !
>  > Yes, a pre-1996 mask 060 (1G65V mask), while my Q60 was built
>  > as bought in 2001 !!!... This makes me wonder how many among
>  > the Q60s have that same buggy processor fitted...
> Probably all full-blown 66 MHz Q60 will have that mask revision. There is 
> nothing wrong about that. Especially as you have the "A" labelled 
> 68060RC60, which should be the best full-blown 68060 silicon ever for 
> overclocking.

I don't know were you got that info (or impression) from, but the XC68060
is said by Amiga folks to be _less_ overclockable than the MC68060.
Example : http://www.amiga-hardware.com/mc68060.html
Citation: "The MC versions tends to be much more tolerant of heat and is
           more tolerant of being overclocked."

I also browsed many Amiga sites today, and all the folks there use 50MHz
MC68060s to overclock them at 66MHz without a single problem...

> I toiled hard to locate them, and you could be a proud owner 
> instead of lamenting.

I didn't accuse -you- and I didn't lament either. I said I was (and still
am) upset. I'm upset, because when my board was built, full blown and
-bugless- MC68060 existed and I end up with a buggy processor that I will
have to replace. I'm upset because Motorola continued to sell buggy
processors from their stock. I'm upset because I was stupid enough to
believe that I would not have to worry about such bugs. I'm uspet because
I didn't check in the available docs before ordering the card and as a
result could not check with you what processor was to be used.

> (The only full-blown chips leaving Motorola fabs at the time I built
> your board were 50 MHz, and I'm quite sure that was not what you wanted.)


MC68060RC60 are available... MC, not XC. Of course, I can't prove they
were available back in 2001, but that's beyond the point as even a RC50
could have been overclocked to 66MHz...

> The 1G65V mask revision is normal mainstream production,

The 1G65V mask _was_ normal mainstream production... It has been replaced
in 1999 with the 0E41J, at which point the processor was renamed from
XC68060 into MC68060: XC is used by Motorola for "Pilot production device"
while MC is used for "Fully qualified parts", clearly indicating that prior
to 0E41J maskset, the 68060 was still considered "experimental" by Motorola.
Product identification:
0E41J product change notice: 

> the 50 MHz speed 
> grade is used in many thousands of Amiga and VME machines. The errata are 
> business as usual, no need to spread public FUD here.

I don't know what 'FUD' means, but I'm simply searching for a bug-less
68060. I'm not trying to spread anything neither to badmouth you.
My message was simply here to both warn people that they could be in the
same situation as mine and to ask for anyone with an available replacement
processor. At least, my warning will have the positive effect to get the
future versions of SMSQ/E fixed for the I14/I15 errata...

>  > I discovered this because Linux v2.4 got a recent fix for the
>  > I14 errata of these buggy processor, and logs the activation
>  > of the fix when the kernel boots. This fix consists in setting
>  > the bit 5 in the PCR (Processor Control Register), which
>  > disables one of the optimisations of the 060. But there are no
>  > less than 21 bugs in the maskset of my 060 !!!...
> If you're already upset about 21 bugs, I wonder how you'd deal with modern 
> chips that have far more bugs. Like a PowerPC derivative to which I've been 
> porting eCos recently :-(

I don't care about other processors, but if you remember all the fuss that
was made about just -one- bug in the Pentium FPU (the "divide bug", I bet
that Motorola was lucky that their processor was not as popular as the
Pentium... On the other hand, the MC68060, which is the "fully qualified"
device, is bugless, and the buggy XC68060 was clearly just a pre-release...

>  > No wonder why
>  > I get weird results each time I try to modify SMSQ/E and QLib_run
>  > in order make them work properly in copyback mode (currently,
>  > QLiberated programs hang/crash/loop randomly when copyback is
>  > enabled).
> Any proof or just guessing? Reminds me of another "hardware bug" which was 
> lamented in public, but turned out a MMU initialization error in SMSQ/E 
> which caused random effects.

I'm searching the proofs, but when you got a processor that can choke on as
simple a code as:

           Bcc LABEL_BANG

LABEL_BANG MOVE An,USP                   <--- I11 errata: USP corrupted !

then, you can worry and make many guesses that will most probably prove
to be good ones in the end...
One thing is certain: I will not loose more time trying to make the copyback
mode work under SMSQ/E, and this until my Q60 is fitted with a bug-less
processor: perhaps will the bug prove to be purely a software one in the end,
but my free time is too precious to loose it trying to distinguish what is
the processor's fault and the software's one, and review the machine code of
hundreds of kilobytes of OS extensions, toolkits and the like to spot the
(correct !) line which fails to execute on my buggy processor...

>  > I'm now in search for a bug-less and full blown 60MHz 68060
>  > (0E41J mask ONLY)...
> I doubt such chips are on the market.



> Thanks for all the flowers, maybe build your own error-free hardware next 
> time.

Once and for all, I didn't incriminate -you- in my message. My -guess- (and
I'm not even interested to know if it is good or not, as if it is bad I
would end up very disappointed), is that you didn't know (just like me)
that the XC68060 you put on my card was buggy. When I asked you to build the
board for me, I did accept to take risks: risk that the board would not work
at all, risk that SMSQ/E would never be adapted to run properly on it, risk
that the postal service would destroy or loose to parcel, risk that the
overclocked processor would burn after a while, etc, etc....

> Or choose one of the million selling companies which will surely 
> serve you better than me.

It happens everyday that companies (big or small) build something (be it
computers, cars, washing machine, rockets, whatever) in all honesty, without
knowing that one of the components they use is faulty and will perhaps trigger
a catastrophic accident later... I my case the only "catastrophic accident" is
an added expense in order to end up with a 100% working system. I can deal
with it. You should deal with your mistake too, like I do with mine. No need
to whine. I don't.

I did thank you for building that board as a very special service you did
to me. I don't regret having bought it, like I don't regret to have thanked
you. I even renew my thanks. But you should know by now that I'm quite frank
a guy (and yes, I'm so frank that I'm often blunt... that's how I am, and at
over 40 it's doubtful that my demeanour will ever improve). When something is
wrong, I say it. I hope you didn't expect me to keep silent about a problem
that may plague most of the Q60 users...

Thierry Godefroy.

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