When loading USBASPI.SYS from a bootable CD ROM disk, the computer loses access to the CD ROM drive. To overcome this, I copy the files to a RAM drive and load the drivers from the there. After this I have the A: (boot sector of CD ROM disk), C: (RAM drive) and D: (CD ROM disk). At this point, I have access to the C: and D: drive but the computer locks if I attempt to access the A: drive. Is this a common problem across all systems or just on my mine? I'm sure I haven't given all the necessary details so let me know and I'll update this post.

More info...I'm booting from a USB CD ROM disk which creates a RAM drive and loads the USB CD ROM drivers. Once this happens, I can no longer access the boot files on the CD ROM disk (A:). Why does this occur and is there a workaround that allows the boot sector of the CD to be accessible after the CD ROM drivers are loaded? More to the story...the real problem is that at some point my system is looking for a file in the A: drive letter...I think. If I put the following line in the autoexec.bat then the problem doesn't occur. c:\dos\subst a: c:\dos I'm using a ruggedized tablet computer running a Phoenix BIOS.

I would guess as no one has, that what you are trying to do is not feasible under M$-DOS, for the simple reason that as far as M$-DOS is concerned an A: drive or a B: drive are floppies. I believe in EZCDCreator 6 when you make a bootable CD you can use SYSTEM files to make a bootable CD ie the CD is A: or it is possible to make a CD which is bootable like in W98. There are several web sites which have info on Bootable CD's and a Google search may be the answer!

More to the story...When I run edit.com from the CD disk, the computer screen goes black. If I unplug the USB CD ROM drive from computer the screen comes back immediately. After I have done this, I can then switch to A: and see all of my boot files on the CD ROM. If the "c:\dos\subst a: c:\dos" is in the autoexec.bat then I can immediately run edit.com and everything works fine.