On Sat, 11 Sep 1999, J.S. Havard wrote:
> 
> What they should have done is created an abstract hardware interface,
> where it would be easy to interface with everything.  Just a generic
> interface.  Only speeds, I/O bandwidth and performance would differ.

This is what was done with the VAX. you should find a compy of VARM and 
read it. The VAX is by far the single most comprehensivley thought out, 
scalable, extensible, well-engineered, and _consistent_ **architecture** 
ever implemented for general-purpose production computers. ever. period. 
Those machines which fully compky to the VAX way of doing things are so
completely like this that its just awesome. Look at a VAX 6000 and you'll 
be drooling. 

> 
> What would be nice would be to create a generic hardware interface for
> some new architecture, say 512 bits wide, in 32bit blocks or so.  In the
> first generation of the architecture, you only use either the first 32 or
> 64 bits.  Later on, you can expand.  Also, you might be able to say, make
> some I/O channels and use the whole 512 bits, although relying on that
> would be risky, if future generations use wider data paths, up to the 512
> bits.  Maybe use the channelizing only for real time and embedded systems.
> Once you reach the 512 bit limit, just make a new architecture.  That much
> advancement should require it.  Disk controllers should have a generic
> interface, memory, serial ports, networking, etc also.  I should be able
> to hardwarily acceses a scsi or ide or even mfm disk the same way.  Think
> sort of like the Emulex qbus scsi host adapter.  It emulates MSCP.  Oh
> well, I think my fantasy architecture would be nice, but nobody in there
> right mind would make it. It is just too good of an idea to actually be
> put in use.  It would be truly plug and play.  Cards plugged into the bus
> would send some sort of identifier stating their type.  Based on slot
> number, they would get priority (disks 0-7 for scsi controller in slot 1,
> disks 8-11 for ide controller in slot 4, etc).  Blech!  I'm falling in
> love with that thing, and it isn't even real.  :-)

sure it is. the VAX _is_ all that and way way way much more. Its all been 
thought through. its all been worked out. its consistent. it works. it is 
powerful, flexible, beautiful. A VAX can be implementedon a single ship 
or it can be a gigantic row of boxes that rivals a mainframe in i/o and 
raw data transfer power. Things like the MSCP and CI are general purpose, 
with protocols like BVP  underneath it all that make everything 
consistent, the concept of a nexus, the concept of uniformly treated bus 
adapters for dealing with U/Q/massbus things in the old days, and the
potential for likewise treating any other bus or io multiplexor, the 
general abstraction one sees, it is beautiful. oh, and the virtual memory 
system. it is spectacular. simple and clean and powerful! everythign else 
was an attempt to copy it! It is at the core of the whole thing, it is 
what allows everythign to work liek this! virtual memory! nowhere else is 
it implementes in such a consistent and clean manner! 


read the VARM!!! 

happy hacking,
isildur