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DOS启动盘 & LOGO技术（启动盘室） » How can a program detect whether the floppy drive or USB flash drive is not installed?

Floor1　szxxbb	Posted 2003-12-21 00:00
初级用户　Posts 8　Credits 133
Problem: USBASPI.SYS and DI1000DD.SYS have already been loaded in CONFIG.SYS. I can read and write the USB flash drive now. But after unplugging the USB flash drive and plugging it back in, I can no longer read or write it. DOS will say it can't find the drive, "Rrtry /Aboart /Fail", and I have to press "A" to exit. How should an application determine this so it won't hang?

Floor2　Wengier	Posted 2003-12-21 00:00
系统支持　Posts 10,521　Credits 27,736
You can also use tools like DREADY (it's included in that super boot disk) to check it.

Floor3　szxxbb	Posted 2003-12-21 00:00
初级用户　Posts 8　Credits 133
Many thanks to Wengier DREADY can detect it now But if I want to add it into my application for automatic detection, could you explain the principle? Using DEBUG to look at DREADY.COM, it seems to use INT21 function 2F AX=2524i int 21 ax=352f int 21 save ES:BX ax=252f int 21 .. dx=参数 ax=252f int 21 reutnr al