Subject: Re: Vwait 250
From: William Nolan <[email-masked]>
To: Martin Kift <[email-masked]>
Cc: [email-masked]
Date: Sat, 20 Aug 1994 08:24:50 -0400 (EDT)

Ok I looked thru the Ref. Manual and I found this interesting little
hack.  I say hack because I'm sure it's probably not a good idea to do
stuff like this, but hey, taking over the system isn't very nice either
:).  Anyway, use this at your own risk.  All it does is check the bit in
PRB to see whether the disk motor is on or not.  It SAYS in the manual
that this bit also tells you whether the drive light is on or off, so it
should work.  I dunno ... all I can say is try it on a blank floppy
before you use it on DH0: .. here it is:

; (hopefully) waits until disk activity
; is done after startup and allows the program to continue (to avoid
; messing up the disk when taking over the system).

CIA_B_PRB	equ $bfd100			; Peripheral Data Reg. Port B

WaitForDiskActivityToFinish:

	move.b CIA_B_PRB,d0
	and.b #%10000000,d0			; check the 8th bit
	cmp.b #0,d0				; if it's equal to 0, then...
	beq.s WaitForDiskActivityToFinish	; the motor is on, so loop...

William Nolan ([email-masked])