Path: utzoo!attcan!uunet!ncrlnk!ncr-sd!hp-sdd!hplabs!amdcad!diablo!phil
From: phil@diablo.amd.com (Phil Ngai)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Usable I/O Address range on the PC bus ...
Keywords: Limited to addresses up to 0x0400 only??
Message-ID: <23581@amdcad.AMD.COM>
Date: 18 Nov 88 20:17:52 GMT
References: <5065@whuts.ATT.COM>
Sender: news@amdcad.AMD.COM
Reply-To: phil@diablo.AMD.COM (Phil Ngai)
Distribution: na
Organization: Advanced Micro Devices, Inc. Sunnyvale CA
Lines: 16

In article <5065@whuts.ATT.COM> jmbj@whuts.ATT.COM (BITTMAN) writes:
|> Every byte that you pick is equivalent to 64 bytes. If you pick byte
|        ^^^^                                ^^^^^^^^
|> 200, you can also use 600, A00, etc. No other hardware can possibly be
|
|Assuming a "byte" here is an I/O address, there are at least 1024
|addresses available for each I/O address claimed, the 8-bit PC XT bus has
|10 "extra" address lines (1024) and the AT has 14 "extra" for a

You seem to have forgotten that IO addresses are either 8 or 16 bits,
but not 20 or 24. My number of 64 is correct, your 1024 is wrong.

--

Phil Ngai, phil@diablo.amd.com
{uunet,decwrl,ucbvax}!amdcad!phil