on 10/31/01 2:55 PM, Chuck Miller at [EMAIL PROTECTED] wrote: > On 10/31/01 1:39 PM, "Sean C" <[EMAIL PROTECTED]> wrote: > >> I took everyone's advice and went to the Velocity Upgrades site, but >> the site says that the Pt Pro can only take 512 mb of RAM, despite >> its 8 slots. Is this true? At these prices, I would like to get 4 >> 128mb chips and add them to my existing two 64mb chips. for a total >> of 640mb. Also, since I know doodly about RAM, how do I know which >> kind of RAM I already have? > > I have a PTP with Sonnet 500mhz G3 upgrade (OS9.1) running 640mb of RAM - > the last 256mb of which is from Velocity. The Velocity RAM is Velocity's > recommendation (EDO) and is installed in the first slots. The rest is > original and add on FPM RAM. Seems fine. Can't absolutely guarantee that all > the RAM is actually in use, but it shows in the About This Computer > window...and I believe I've had most of it working at one time. > The only problem with the extra memory is what is called "addressing". The computer chip set has a built-in limit to the amount of RAM it can store an addrss to, and anything you add above that amount simply will not be useable. As an example, if I have four yes/no toggle switches, I can have sixteen possible combinations of yes and no that are unique.
In the hardware of the PT Pro are the equivalent of 2^9 switches that can address a total of 512 unique combinations of zeroes and ones. The "About" window merely counts how much is installed, but has no connection to the actual hardware that addresses the memory. Jim Snyder -- Power Computing is sponsored by <http://lowendmac.com/> and... 123Inkjets.com <http://lowendmac.com/ad/123inkjets.html> Support Low End Mac <http://lowendmac.com/lists/support.html> Power Computing list info: <http://lowendmac.com/power/list.html> Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> List archive: <http://www.mail-archive.com/powercomputing%40mail.maclaunch.com/> Using a Macintosh? Get free email and more at Applelinks! <http://www.applelinks.com>
