139Chapter D - Using Microsoft MS-DOSslightly, depending on whether you use the corelSCSI software (by Corel) or the ASW soft-ware (by Adaptec). Regardless of which company's ASPI module you choose to use, theASPI manager of the GDT controller (located on the GDT System Disk - DOS) has to beloaded from the CONFIG.SYS file. The objective of both installations is to make the CD-ROM drive accessible as a drive (for example drive E) under MS-DOS or Windows, and tobe able to access this drive just as if it were a (write-protected) floppy disk in drive A or B.At this point we presume that the CD-ROM drive has been properly connected to the GDTcontroller. This includes that the SCSI-ID and the SCSI bus terminators are set in acco r-dance with the settings of the already existing SCSI devices (i. e., the SCSI-ID chosen forthe CD-ROM drive is not occupied by another device; resistor terminators are located onlyat the two ends of the SCSI bus).D.6.1 Example: Using an ASW ASPI Module for the NEC CD-ROMThe important lines in both files are printed bold.CONFIG.SYSdevice=c:\windows\himem.sysdevice=gdtx000.exefiles=30buffers=30stacks=9,256dos=high,umbshell=\COMMAND.COM /E:512 /Pdevice=\dos\setver.exedevice=\gdt\gdtaspi.exedevice=\aspi\aswcdnec.sys /D:CD-ROMlastdrive=hAUTOEXEC.BATpath=c:\;c:\dos;c:\gdt;c:\aspi;prompt $P -$Gdoskeyc:\aspi\mscdex /D:CD-ROMThe GDTX000.EXE driver is loaded from the first line following the HIMEM.SYS commandof the CONFIG.SYS file. Loading the SETVER driver (part of MS-DOS) allows older versionsof Microsoft's CD-ROM translation program MSCDEX (loaded from AUTOEXEC.BAT) to runtrouble-free with the MS-DOS version currently installed. The next line loads the GDT ASPIManager GDTASPI.EXE. Next, the ASW ASPI module for the NEC CD-ROM drive is loaded.The parameter "/D:CD-ROM" has nothing to do with a drive name, it only serves as a reco g-nition information for MSCDEX. As mentioned before, it is our objective to be able to a c-cess the CD-ROM drive with a drive name (i.e. E). Naturally, this drive name has to be"free", and there have to be enough drive names available. For example, the DOS commandLASTDRIVE=H would allow to use drive names from A to H. In the AUTOEXEC.BAT file, theMicrosoft translation program for CD-ROMs (MSCDEX - Microsoft CD-ROM Extension) isloaded. It is not part of MS-DOS (except for version 6). The parameter /D:CD-ROM set herehas to be identical to the parameter set after the ASPI module in the CONFIG.SYS file. Aftera warm reboot which serves to activate the changes made in the CONFIG.SYS andAUTOEXEC.BAT files, the NEC CD-ROM drive can be accessed as drive E (in our examplethere are two SCSI hard disks in the PCI computer, and under MS-DOS they are accessed asC and D). Drive E can be accessed under Windows, too, now (the Icon next to "E" indicates
