[net.micro.att] Hard Drive Slows Memory?

ksb@homxa.UUCP (K.BANDES) (02/12/86)

Someone named Brad writes

> I found out today that if you add a third party hard drive to a 
> 6300 (on the 8-bit bus) the cpu slowes down to the speed of an IBM PC
> while access that memory.  

What exactly does this mean?  How could a hard drive (or anything else)
slow down the cpu?  Should I worry?  (I have a 6300 with a third-party
hard drive.) 

Ken Bandes
AT&T IS

Disclaimer:  I'm not responsible for anyone's grammer but my own.

guzzi@uiucdcsb.CS.UIUC.EDU (02/15/86)

>
>/* ---------- "Hard Drive Slows Memory?" ---------- */
>Someone named Brad writes
>
>> I found out today that if you add a third party hard drive to a 
>> 6300 (on the 8-bit bus) the cpu slowes down to the speed of an IBM PC
>> while access that memory.  
>
>What exactly does this mean?  How could a hard drive (or anything else)
>slow down the cpu?  Should I worry?  (I have a 6300 with a third-party
>hard drive.) 
>
>Ken Bandes
>AT&T IS
>
>Disclaimer:  I'm not responsible for anyone's grammer but my own.

	I was also puzzled when I first read this.  I think you
sould substitute "memory expansion card" for "hard drive" in the above
message.  All expansion cards for the ibm pc use an 8 bit data bus while
the pc6300 uses a 16 bit data bus.  If you put in an 8 bit memory card,
then the 6300 will slow down to the speed of an ibm pc when accessing
memory on the 8 bit bus.  
		      --Mark Guzzi
			University of Illinois at Urbana-Champaign
		        ARPA:	guzzi@uicsrd.csrd.uiuc.edu   
				   guzzi%uicsrd@uiuc.arpa
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			UUCP:	{ihnp4,convex,pur-ee}!uiucdcs!guzzi
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tue@olamb.UUCP (Tue Bertelsen) (02/17/86)

It is only the presence of a memory board with an 8-bit access path
that can slow down the PC6300 (and the Olivetti M24 here in Europe).
It will however not be as slow as the IBM PC, due to the higher
clock frequency.

I remember seeing an announcement of a PC6300 compatible memory board
from AST.

However, why don't you just plug in 256Kbit RAM's in the motherboard.
It is prepared for it and your dealer/service center should be able to
do it. That's what we do here in Europe, but we are not so clever !


-- 
						Tue Bertelsen
						AmbraSoft A/S
						tue@olamb.UUCP

bam@sdchem.UUCP (Bret Marquis) (02/23/86)

The earlier 6300's did not have sockets for the additional
memory.  for 640k your had to use another board.



Bret Marquis
(sdcsvax, ihnp4) bang!bam

gpw@ihlpf.UUCP (Wilkin) (02/25/86)

> The earlier 6300's did not have sockets for the additional
> memory.  for 640k your had to use another board.
> Bret Marquis
> (sdcsvax, ihnp4) bang!bam

If you would consider a MAC upgrade, you would consider removing the ram chips
from the motherboard. Then replacing them with sockets and 256k ram chips.
It is worth it if you need all the slots. Or if you want your memory fast
( if you currently use the 2 connector type board - this won't gain you much)
it is the best way to go.
gpw
-- 

George Wilkin                                  AT&T Network Systems   
work 312-979-6593 ihnp4!ihlpf!gpw              Naperville-Wheaton Road
                                               Naperville, IL