Repost: DOS Memory Management Animation Illustration - DOS Memory Map Flash - China DOS Union Forum

### Overview

The memory of a microcomputer includes conventional memory, reserved memory, upper memory, extended memory, and expanded memory.

A relationship diagram of these five types is shown in the animation.

### Conventional Memory

1. Interrupt vector area: The address range is 00 - 3FFH, occupying 1KB, also known as the interrupt vector table area.
2. BIOS data area: The range is 400 - 4FFH, occupying 256 bytes, for special programs BIOS to store data.
3. System data area: The address range is 500 - 6FFH, occupying 512 bytes, a small area for the operating system to store information, storing initialization information when the computer starts.
4. Application memory area: The range is 700 - 9FFFH, occupying 638KB, usually the memory area for running programs.

### Reserved Memory Area

384KB above 640KB

1. Video memory area: (1) EGA/VGA graphics area; (2) Monochrome text memory area; (3) Color text memory area
2. Video ROM area
3. Unused area
4. Extended BIOS ROM area
5. System BIOS ROM area

Flash demonstration (if the link is invalid, please download the attachment)

Web page link:
http://etsc.hnu.cn/jxzy/lxkj/2002/data/%CE%A2%BB%FA%D7%E9%D7%B0%D3%EB%C8%ED%CE%AC%BB%A4/c1/314.html
Animation link:
http://etsc.hnu.cn/jxzy/lxkj/2002/data/%CE%A2%BB%FA%D7%E9%D7%B0%D3%EB%C8%ED%CE%AC%BB%A4/flash/wznct.swf

[ Last edited by willsort on 2005-12-6 at 14:13 ]

Floor1　willsort	Posted 2005-12-06 14:10
元老会员　Posts 1,512　Credits 4,432
### Overview The memory of a microcomputer includes conventional memory, reserved memory, upper memory, extended memory, and expanded memory. A relationship diagram of these five types is shown in the animation. ### Conventional Memory 1. Interrupt vector area: The address range is 00 - 3FFH, occupying 1KB, also known as the interrupt vector table area. 2. BIOS data area: The range is 400 - 4FFH, occupying 256 bytes, for special programs BIOS to store data. 3. System data area: The address range is 500 - 6FFH, occupying 512 bytes, a small area for the operating system to store information, storing initialization information when the computer starts. 4. Application memory area: The range is 700 - 9FFFH, occupying 638KB, usually the memory area for running programs. ### Reserved Memory Area 384KB above 640KB 1. Video memory area: (1) EGA/VGA graphics area; (2) Monochrome text memory area; (3) Color text memory area 2. Video ROM area 3. Unused area 4. Extended BIOS ROM area 5. System BIOS ROM area Flash demonstration (if the link is invalid, please download the attachment) Web page link: http://etsc.hnu.cn/jxzy/lxkj/2002/data/%CE%A2%BB%FA%D7%E9%D7%B0%D3%EB%C8%ED%CE%AC%BB%A4/c1/314.html Animation link: http://etsc.hnu.cn/jxzy/lxkj/2002/data/%CE%A2%BB%FA%D7%E9%D7%B0%D3%EB%C8%ED%CE%AC%BB%A4/flash/wznct.swf [ Last edited by willsort on 2005-12-6 at 14:13 ] Attachments MemoryMap.rar (24.47 KiB)

Floor2　220110	Posted 2005-12-06 14:52
荣誉版主　Posts 313　Credits 718
UP！！ Is there a follow-up?

Floor3　bear111	Posted 2005-12-07 01:03
新手上路　Posts 5　Credits 9
Simple and intuitive, thank you.

Floor4　fdsiuha	Posted 2005-12-07 20:31
高级用户　Posts 302　Credits 587
Very good teaching courseware!

Floor5　wl00560	Posted 2005-12-09 20:39
银牌会员　Posts 709　Credits 1,384
Still a bit unclear. Is the page frame in the umb? Which area is it in? According to the picture, the umb can have at least 160K, but it's hard to reach. Why?

Floor6　kamuli	Posted 2010-03-17 11:53
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Just saw it now, I've been looking for a long time, but that link has expired, hope I can still see it.

Floor7　qq285851893	Posted 2010-03-17 18:21
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Floor8　whmust	Posted 2010-08-12 11:42
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Floor9　xiyuqiao	Posted 2010-09-02 23:25
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Floor10　heiheihaha	Posted 2010-09-03 13:32
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Let me download and try it

Floor11　windwenguan	Posted 2010-10-26 17:55
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Floor12　adef	Posted 2010-11-04 16:10
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Thanks, still not understanding this.

Floor13　danjiang	Posted 2010-11-05 14:38
初级用户　Posts 45　Credits 79
Not bad. There is a question: Where does the color graphics area 0A000 come from?

Floor14　dillond	Posted 2010-11-05 14:38
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The basic things must be understood clearly

Floor15　ai3471118	Posted 2010-11-11 00:16
新手上路　Posts 8　Credits 16
The link has expired.