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DOS启动盘 & LOGO技术（启动盘室） » How did the Super MS-DOS 7.10 boot disk manage to get more than 800K of upper memory?

Floor1　bhore	Posted 2004-02-21 00:00
初级用户　Posts 14　Credits 141
I've been making boot disks myself. After loading with EMM386 /NOMES and UMBPCI, I can only get a bit over 80K of upper memory. I don't know what else was added in the Super MS-DOS 7.10 boot disk, so I'd appreciate it if an expert could let me in on it. When I manually choose not to load IFSHIP.SYS, I still get only a bit over 80K, but if I put this file onto my own disk and boot from it, it's still only a bit over 80K, and I also didn't see any loading option for it in the Super MS710 config...... I really want to know

Floor2　Wengier	Posted 2004-02-21 00:00
系统支持　Posts 10,521　Credits 27,736
IFSHLP.SYS uses very little memory, so actually there's no need to worry about it.

Floor3　bhore	Posted 2004-02-21 00:00
初级用户　Posts 14　Credits 141
You still haven't said how to reach more than 800K of upper momoery. It's not a typo on my part, it really is more than 800K, not 80K.

Floor4　Wengier	Posted 2004-02-21 00:00
系统支持　Posts 10,521　Credits 27,736
More than 800KB of upper memory, really? Don't kid around, it's completely impossible. And at present no DOS boot disk can do that. If you say it wasn't a typo, then you must have gotten it wrong.

Floor6　MYS	Posted 2004-02-21 00:00
元老会员　Posts 1,637　Credits 5,170　From 广东佛山
The UMB area is located in DOS's reserved area, and that reserved area is only 384K in size, so how could you possibly get 800K out of it? When IBM PCs first came out, they could only access 1024K of memory. Of that, 640K was left for DOS, while 384K was reserved for other uses. To maintain compatibility, this standard cannot be changed unless you make an entirely different DOS.

Floor7　bhore	Posted 2004-02-21 00:00
初级用户　Posts 14　Credits 141
I also think it's unbelievable. It's just that I found this happens when DOSLFN can be loaded into UPPER (without loading smartdrv).

Floor8　bhore	Posted 2004-02-21 00:00
初级用户　Posts 14　Credits 141
If smartdrv is loaded, doslfn seems unable to load into upper, and then it's only a bit over 80K. I'm using VMware 4.05, so maybe it's a VMware issue. But if I use the files from a boot disk made by a Win98 system to boot, then whether I load doslfn or not, it never reaches that number. But if I copy the files from your disk (command.exe, io.sys, msdos.sys, himem.sys, doslfn...... and so on, basically the files used during boot) onto a disk I made, then it can also reach 800K.

Floor9　bhore	Posted 2004-02-21 00:00
初级用户　Posts 14　Credits 141
By the way, when using mem, what does the Reserved shown below upper refer to? Reserved memory? 384K? Why is it sometimes 0, and sometimes 30M...?