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in article <17479@gatech.edu>, ken@gatech.edu (Ken Seefried III) says:
> Summary: One of a million followup questions...
> Xref: cbmvax comp.sys.misc:1941 comp.os.misc:565 comp.misc:4233 comp.arch:6833

>>Mass storage is on a 256 MB removable erasable
>>optical disk! Jobs said that the removable media goes for ~$50. The display

> 	     I spent a little time doing work with optical disk technology,
> 	     and it was far, far to slow to be primary main storage.  What
> 	     magic has NeXT worked to make it suitable?

They say it's DMA driven and has an 8K static RAM cache.  The words "very 
little" come to mind.  Certainly stuff's going to be cached in DRAM as
well; the standard setup is 8 megs.  But 96ms is SLOW...

>>the NuBus. The NuBus is run at 25 MHz (Jobs compared it to a 10 MHz NuBus,
>>is this what the Mac II uses?). 

> 	Several questions...I thought that NuBus was standardised to 
> 	run at 10MHz, synchronous.  Is 'NuBus' running at 25MHz still
> 	NuBus?  Will not most availible NuBus cards choke?

I'd sure expect all available NuBus cards to choke.  Not only is NuBus set at
10MHz, but this NeXT bus is also apparently defined at CMOS, not TTL, levels.
Certainly that'll kill the one standard NuBus card that would have otherwise
worked.

However, it might make some sense.  While NuBus isn't a great match to the
680x0 family, certainly running NuBus synced to the host CPU is going to
eliminate the sync-up slowdowns you see in a machine like the Mac II.  And
if they are otherwise NuBus, perhaps they're counting on developers to 
figure that a redesign for NeXT is a much smaller step than going to a
completely different bus.  Or perhaps they don't care about 3rd party devices,
planning instead to populate that bus with additional CPU cards and PIXAR
things.

> 	Also, what form factor are the cards: the original (MIT/TI)
> 	Eurocard or the Apple form factor?  

The size certainly implies Eurocard; the whole computer is actually on a
card.  Apparently the box is really just a backplane and power supply.

>>                   , some kind of floppy drive for software distribution,
>>etc. I imagine a typical SCSI tape drive could be used for archival
>>storage.

> 	umm...Why?  The optical is removable, no? non-volitile?
> 	indestructable? 256MB?  Seems like a pretty good 
> 	backup/distribution media to me...

So you're going to spring for the second optical drive.  Or copy 256MB, 7.5Meg
at a time, in an 90's version of the old "floppy shuffle".  I guess any real
power used is going to need a real hard drive anyway; I could think of worse
than 256Meg floppies...

>>Jeff Lo

> 	ken seefried iii	...!{akgua, allegra, amd, harpo, hplabs, 
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