Date: Thu, 27 Aug 1998 07:42:12 -0400 (EDT) From: John Baldwin <jobaldwi@vt.edu> To: (Mike T.) <miky@pcnet.pcnet.ro> Cc: hackers@FreeBSD.ORG Subject: RE: what relation is between the microproc,highway & disk size Message-ID: <XFMail.980827074212.jobaldwi@vt.edu> In-Reply-To: <691@miky.pcnet.ro>
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-----BEGIN PGP SIGNED MESSAGE----- On 26-Aug-98 Mike T. wrote: Everyone feel free to correct me if I get this wrong... > Hy folkes, hy Gary ! > > Gary Kline <kline@tao.thought.org> wrote: > > > My newer 6x86 that was damaged late last June has been restored to > > a P200 with 64MB and still has its 10GB of disk. > > > Pls.excuse me if I'm intruding,I have a question,it may be a little > off-topic,but since I read the 2 lines above I have no peace finding > out this : > > - What relation is between the microprocessor,the number of bits of > the computer (or microprocessors) highways and the maximum disk size > that the microprocessor can access ( see ) ? For all intents and purposes, none. > - I'm asking this because I read somewhere that a certain micro.,not > remember now what it was,could not access ( see ) more than 4GB. I think you are getting RAM limits mixed up with hard drive limits. The 8088/8086 could only 'see' 1 Meg RAM. The 286, with the advent of Protected Mode could see 16 Meg RAM. With the 386, Intel revamped protected mode to allow a total addressable space of 4 Gig. On some Pentium Pro's (and PII's ??) there is a special processor extension that allows it to see 64 Gig. However, these sizes are for RAM, not hard drive size. What really determines the maximum size hard drive that your system can see is your I/O controller. Due to a combination of BIOS and IDE limits, plain IDE cards can only see a disk of 528 MB or less. When that became a problem, bios translations (the most popular form of which is LBA, Logical (large?) Block Addressing) were used to fudge the limits. With LBA, I/O controllers can handle disks up to 8.4 Gig. Now, here I enter murky waters myself: there is a new standard of some sort that allows disks > 8.4 Gig to be accessed, unfortunately I have no idea what it is called or how it works, hopefully somebody else can help you with that. > - So I suppouse that I can't access with a 286 ,say a 10GB disk. Technically, if you could get an ISA board with one of the new controllers, then it should work, although the BIOS on a 286 motherboard probably can't handle it, but I could be wrong, it might handle it just fine. > - Happily,I own a Intel-Pentium-133MHz.Would he "see" a 10GB disk if > I'll buy one ? Depends on your I/O controller. If it just supports standard LBA, you will only see the first 8.4 Gig of it, AFAIK. > please enlight me. > miky@pcnet.pcnet.ro Hope this helps. John Baldwin - -- jobaldwi@vt.edu -- jbaldwin@freedomnet.com -- ---- http://www.freedomnet.com/~jbaldwin/ ---- "I waited for the Lord on high/I waited and He heard my cry." - Petra -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQB1AwUBNeVFCIjYza302vYpAQF7OAL/ey47xHq04PX/D4K6KDvMXQq1t5j7DHPc gHCkEMWuOJ9UI5n5DcLPnCEVIvsDLMU4nfwBw/Jx+SuYAjo1ftTmMcs3A/U138ia ASpZLvBf8/HUhpDcBCbZamNTdheCQ+Ha =Gp21 -----END PGP SIGNATURE----- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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