🚀 go-pugleaf

>>Didn't he say it was a VL card?  That means that the CPU can't do
>>anything anyway, since when the disk controller has the local bus the
>>CPU can't talk to memory or anything anyway.  This is why I don't see
>>VL as a real win for anything except perhaps video; it will give you
>>great burst mode numbers, but it impacts overall system performance to
>>do that.  
>
>That doesn't make any sense. The only way to minimize the hit the CPU
>takes when doing DMA is to make the DMA go as fast as possible, which is
>what VLBus does. There's no free lunch. :)

  I'm on the verge of upgrading my 486DX-33 ISA machine to a 33MHz
VL-ISA motherboard that can handle a DX2 chip (To head off the
tangential questions now, there's a problem with my motherboard, and
the dealer's letting me swap up to what I think is a better
motherboard for a little more money).

  Is the VL bus an improvement or not?  I thought VL-ISA would be
superior to an EISA bus for my needs.  I mean, aside from video and
hard disks (2 VESA slots) what COMMON applications are there for DMA
transfers > 5MB/sec?  I suppose loading data into a soundcard's buffer
is one, but the industry is just starting to take advantage of the
16bit DMA channels (4-7) on the ISA bus (Gravis Ultrasound Card).

  I never put together that VL cards lock up the local bus to do their
transfers, whereas DMA transfers to/from an ISA card DON'T!!  Is this
true?  I know MS-DOS and MS-Winows (I think) aren't smart enough to
be impacted by this, but can anyone comment on whether any PC UNIX (Linux?),
Windows-NT, or OS/2 operating systems are intelligent enough to be
impacted, and how bad would it really be?

  Morgan
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