leendert@cs.vu.nl (Leendert van Doorn) (12/11/89)
Hello Netlanders, I'm looking for some information about the RT/CMOS chip in my AT. I've got some information, which I'll summarize below, but I need some more data on the addresses. Currently I know the following addresses on my RT/CMOS chip: Description Address ----------------------------------------------------------- Real Time Clock 0x00 - 0x0D floppy disk type 0x10 hard disk type 0x12 diskette, video, and coprocessor info 0x14 What I would like to know is the exact layout of these addresses. For example, address 0x12 contains a harddisk descriptor. The bits 7-4 describe the first drive. The value contained is an index into a table. Question 1: Do the bits 3-0 (address 0x12) describe the second harddisk ? Question 2: Does the same apply to address 0x10 (the floppy disk drives) ? That is, do the bits 7-4, 3-0 describe the floppy drives 1 and 2. And does address 0x11 describe the floppy disks 3 and 4 in the same way ? Question 4: I just got myself a table out of my AT describing about 40 harddisk types. Does anyone have a full (= more extensive) table ? Question 3: Address 0x14 contains information about diskette (number ??), video and coprocessor. How is this information stored ? Currently I known of 4 types of videos, EGA, COLOR 40, COLOR 80, and MONO. Is that all there is ? (NO?:-). Question 4: What other addresses do exists ? Most of this information comes from a header file describing the Motorola MC146818 RealTime Clock/RAM chip. So forgive me my ignorance. Since I'm not a very regular News reader, please email the replies (reading news takes up a considerable amount of time :-). If there is enough interest, I'll try to post a summary. Thanks, Leendert -- Leendert van Doorn <leendert@cwi.nl> Centre for Mathematics and Computer Science <leendert@cs.vu.nl> Amoeba project / P.O. Box 4079 1009 AB Amsterdam / The Netherlands From: leendert@cs.vu.nl (Leendert van Doorn) Newsgroups: comp.os.minix,comp.sys.ibm.ps Subject: AT - CMOS RT/RAM chip info wanted Expires: References: Sender: Reply-To: leendert@cs.vu.nl () Followup-To: Distribution: world Organization: VU Informatica, Amsterdam Keywords: AT, cmos chip Hello Netlanders, I'm looking for some information about the RT/CMOS chip in my AT. I've got some information, which I'll summarize below, but I need some more data on the addresses. Currently I know the following addresses on my RT/CMOS chip: Description Address ----------------------------------------------------------- Real Time Clock 0x00 - 0x0D floppy disk type 0x10 hard disk type 0x12 diskette, video, and coprocessor info 0x14 What I would like to know is the exact layout of these addresses. For example, address 0x12 contains a harddisk descriptor. The bits 7-4 describe the first drive. The value contained is an index into a table. Question 1: Do the bits 3-0 (address 0x12) describe the second harddisk ? Question 2: Does the same apply to address 0x10 (the floppy disk drives) ? That is, do the bits 7-4, 3-0 describe the floppy drives 1 and 2. And does address 0x11 describe the floppy disks 3 and 4 in the same way ? Question 4: I just got myself a table out of my AT describing about 40 harddisk types. Does anyone have a full (= more extensive) table ? Question 3: Address 0x14 contains information about diskette (number ??), video and coprocessor. How is this information stored ? Currently I known of 4 types of videos, EGA, COLOR 40, COLOR 80, and MONO. Is that all there is ? (NO?:-). Question 4: What other addresses do exists ? Most of this information comes from a header file describing the Motorola MC146818 RealTime Clock/RAM chip. So forgive me my ignorance. Since I'm not a very regular News reader, please email the replies (reading news takes up a considerable amount of time :-). If there is enough interest, I'll try to post a summary. Thanks, Leendert -- Leendert van Doorn <leendert@cwi.nl> Centre for Mathematics and Computer Science <leendert@cs.vu.nl> Amoeba project / P.O. Box 4079 1009 AB Amsterdam / The Netherlands