This might be a good thread to insert this mildly OT request. stockholm, my Apple Network Server, which has a couple of years before going on-topic, needs 60ns parity DIMMs. Anyone know of a good source at a good price? I need to order two 32MB modules for it so I can upgrade stockholm to 128MB. I sniffed around a few places but no one seems to sell parity RAM anymore, and PC100 DIMMs will obviously not cut it. It's an old Mac, really. :-) -- ----------------------------- personal page: http://www.armory.com/~spectre/ -- Cameron Kaiser, Point Loma Nazarene University * ckaiser(a)stockholm.ptloma.edu -- I am Dyslexic of Brog. Fesistence is rutile. You will be asmilsilated. -----

"Bill Layer" <b.layer(a)vikingelectronics.com> wrote: No. The 68040 (all variants including the LC and EC) require a double-speed clock input, but the internal pipeline does NOT execute at the double speed. A 68040 with 33 and 66 MHz clock inputs actually runs at 33 MHz. Motorola documentation is very clear on this. As soon as Motorola atarted sending out "advanced information" data sheets it became apparent that this would cause a lot of confusion. Think of it more like a 2 MHz 8080 that requires a two-phase clock. It does some internal things on one phase and some on the other. The 68040 is similar but derives the phases internally from a double-speed clock. And before someone tries to "correct" me, yes, I do know that the 68040 is CMOS, and does not use traditional two-phase NMOS logic structures like the 8080. The reason it needs multiple phases is simply due to the way the pipeline is structured. More modern high-end microprocessors have internal PLLs or DLLs to synthesize the various necessary internal timing signals so that there is only one clock input, and usually that clock input is at a much lower frequency than the pipeline.

I wrote: Bill Layer wrote: I'm not on any crusade to kill it. But I'll comment when and where I happen to see it. It matters not one bit to me that there's a lot of bogus information about it on the web. None of that has any credibility since it is flat out contradicted by an authoritative source, the MC68040 User Manual. Apple's calling them 50 or 66 MHz is an example of what's known as a "marketing breakthrough". See the TV "Dish" Antenna advertisement on the milk.com Wall of Shame for a particulary good example of this phenomena. What especially distinguishes that particular marketing breakthrough is that they actually explicitly claim IN THE ADVERTISEMENT that it is "a marketing breakthrough"! http://www.milk.com/wall-o-shame/dish.html Best regards, Eric