> Quite a while ago, when we had the same discussion, I showed you some > documentation (PC DOS stuff afair?) which explicitly states that you > can use int 21.01 ... int 21.0c at almost any time. That includes that > you can use them from within SYS files and from within device init. > > Ah. Here it is. You can use system calls 01H-0CH and 30H during the > initialization code of the driver. Arkady also clarified that FORSYS > means "for the SYS.COM tool". While you are at it, do not forget to > fix the wrong call for non-Turbo-C compilers in prf.c, as mentioned. > > PC DOS 7 Tech: http://www.redbooks.ibm.com/redbooks/pdfs/gg244459.pdf
It is also stated in "Advanced MS-DOS Programming" book by Ray Duncan (published by Microsoft Press). Download: http://alexfru.narod.ru/miscdocs/adv_dos/adv_dos.zip (very slow link) Quote from chapter 14 "Installable device drivers": "The operating-system services that the initialization code can invoke at load time are very limited only Int 21H Functions 01H through 0CH and 30H. These are just adequate to check the MS-DOS version number and display a driver-identification or error message." -- Kristaps Kaupe, http://kristaps.netparks.lv
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