RAM drives and physical/logical drives

[WYLIE Andrew]

Hello,
      I am having some problems with the second ram disk (RAM.SYS + SETRAM)
which was recently posted to the net. This has raised some questions about
disk drives in general which I hope someone out there can help me with.
  The problem I have with SETRAM is that  SETRAM d N works, but SETRAM e N,
or any drive greater than d:, gives the error
   error number 15 (decimal)
so that I can only create one ram disk. (I shall ignore the temptation to
elaborate on the wonderfully informative nature of the error message).
   Now, if I do a simple DIR d:, I get the message
        Not ready error reading drive d
   whereas DIR e: gives
        Invalid drive specification
I assume that this is related to the fact that the diagnostic diskette tells
me that drive d is not installed, but says nothing about drives e,f,g... etc.

All of this is completely unchanged if I set LASTDRIVE=Z in CONFIG.SYS

The questions I have are :
1/ how does the diagnostic prog think that drive d exists (but is not installed)
   but that higher drive numbers do not ?
2/ does LASTDRIVE actually do anything ?
3/ can I make the PC think that more drives exist but are not installed ?
4/ will this cure the ram drive problem ?

Andrew Wylie, Univ. of Geneva, Switzerland
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