la@doc.ic.ac.uk (Liaket Ali) (10/15/90)
Help! I am writing a level editor for a game which I am developing on the AMIGA 500. The editor requires the use of the blitter quite extensively. Therefore in order to use the blitter in the Multitasking operating system, I have used the ROM routines: OwnBlitter(),WaitBlit() and DisownBlit(). However this seems to make the drive lock up. For instance if I insert a disk while my program is running (to save/load data) then the drive chugs a bit and then stops with the light staying on! Then when I quit my program , the system tells me that there is no disk in the drive! (even if I reinsert the same disk or a different disk). I would appreciate any help. My system is an AMIGA 500 KS1.3, with 1MB Ram + Clock and External drive. The editor is written in assembly language and the graphics use a 5 bitplane 320*256 display. Thanks in advance. LIAKET ALI aka la@doc.ic.ac.uk
IMS103@psuvm.psu.edu (Ian Matthew Smith) (10/17/90)
If I remember right, the blitter is used in read/write operation on the Amiga 3.5 floppies. Disk buffers have to be in CHIP mem so I assume some of the DOS routines need to use some blitter functions when you have owned teh blitter. Ian Smith <ims103@psuvm.bintet>
pochron@cat27.cs.wisc.edu (David Pochron) (10/20/90)
Your problem appears quite simple - you are "owning" the blitter during disk read/writes, and the trackdisk.device needs the blitter to decode the data on the disk! You should never hog the blitter for the entire run of a program - do all your blitter calls into one part of the code, and surround them by Own/Disown() blitter calls. My Ultima shader/scroller routine owns the blitter, draws all the screen graphics with the blitter, then disowns it. This is the only proper way to program the blitter without being "rude" to the system. One other thing: make sure that you ALWAYS wait for the blitter activity to be done, even if you are using "blitter nasty" mode - since most asynchronous CPU cards continue to run even with "blitter nasty" turned on! (I know -- I found out the hard way!) -- ------------------------------------------------------------------------------- David M. Pochron | from Rescue Rangers, _A Fly in the Ointment_ pochron@garfield.cs.wisc.edu| Gadget to Dale: "Keep the hands off the body!" -------------------------------------------------------------------------------