Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!deimos.cis.ksu.edu!eecea!psb
From: psb@eecea.eece.ksu.edu (Phil Buckland)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Turbo Mode
Message-ID: <667@eecea.eece.ksu.edu>
Date: 3 Jul 89 20:38:03 GMT
References: <46200003@attcc.UUCP>
Reply-To: psb@eecea.UUCP (Phil Buckland)
Organization: Kansas State University, Manhattan
Lines: 38

In article <46200003@attcc.UUCP> you write:
>
>I am having trouble getting the turbo mode on my XT clone to work now that 
>I have added 384K on a Zuckerboard to complete the 640K.
>Turbo worked fine before the expansion. (It has an actual turbo switch to 
>select the speed.)

	Have you made sure that the DRAMs which you added are fast enough?
	There is a suffix on the part number which specifies the guaranteed
	access time of the DRAM.  The lower the number, the faster the access
	time.  In particular, the DRAMs you added to the Zuckerboard should
	be at least as fast as the DRAMs already on the motherboard.

	4164-15: 150ns 64K X 1 DRAM	4164-12: 120ns 64K X 1 DRAM

>The motherboard is a Super K.  I had to experiment with the jumpers first to 
>allow access to the added memory. Got that finally, but no Turbo.
>Should I have added the 384K to the motherboard first? (It is full of 64K 
>chips.)  I've tried software switches to no avail. They either do nothing or 
>lock up the system.

	If the motherboard is fully populated (eg, no room for any more
	chips), then you have no worries.  If there *is* room on the
	motherboard for more memory chips, it is a good idea to fill those
	empty sockets before putting chips on an expansion card.

>HELP!!

	Ask, and you shall receive.

				Phil Buckland
				Computer Engineer
				Kansas State University

				psb@eecea.UUCP
				psb@eecea.eece.ksu.edu

P.S. Sorry to have had to post.  My E-mail to you bounced.