Date: Thu, 30 Oct 2003 10:59:21 -0500 From: "Lewin A.R.W. Edwards" <[EMAIL PROTECTED]> Subject: Re: [LIB] Amount of memory addressable??
Actually--sorry--I miswrote. It has a 32 bit address buss which Toshiba did not use all of. If they had we could use 168 pin sodimms to upgrade
You don't get it. The Pentium has a 32-bit address bus, yes. You could put 4Gb of SRAM on it. But it addresses main memory through a DRAM controller. The DRAM controller is designed to support devices of specific densities. From the pinouts you posted, it can handle devices with up to 4K sizes.
Actually it is not limited at all since computer memory has not been dependent on the width of the address buss since what?!? never? The idea
Ah. Okay. You really need to avoid talking about things of which you have no comprehension, although it is quite humorous.
Heh--it has a programmable GA setup as a edo dram controller. It is
It's a mask-programmed ULA or a straight-out ASIC. There is no way it's an FPGA.
never a problem to access a differant type of ram as long as the new ram
Yeah, yeah, etc. If you're capable of reading a timing diagram, go to www.partminer.com and download an SDRAM datasheet, say Toshiba TC59S6416CFT, and compare it with an EDO datasheet, say VG2618165CJ.
need to hack a Libretto module? The pinout of the expansion connector is same as a 144 edo sodimm. No hacking needed. I thought of a sodimm first
Might be true, but the connector is proprietary.
There is no limit to the memory the bios can see.
There most certainly is - because it has to set up the GA for the correct bank size and refresh parameters. Of course, you'd know this if you had written POI code for hardware of this type.
By the way, you might want to check my bona fides for making statements like this. Have a look at www.zws.com and in particular the DF-390 and DF-560 products, for which I designed the hardware and wrote the firmware. The DRAM subsystems in these devices are very similar to PCs of Libretto vintage. Or, to put it another way: I do this type of thing for a living.
-- -- Lewin A.R.W. Edwards (http://www.larwe.com/) Learn how to develop high-end embedded systems on a budget! http://www.amazon.com/exec/obidos/ASIN/0750676094/zws-20
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