Received: from mea.utu.fi by MAMMUTTI.UTU.FI ; 18 Feb 90 16:56:01 EET Received: by mea.utu.fi (5.51/10.6.master) id AA10536; Sun, 18 Feb 90 16:58:46 +0200 Message-Id: <9002181458.AA10536@mea.utu.fi> From: mea@mea.utu.fi (Matti Aarnio) Subject: reboot a PAL machine into NTSC (fwd) To: fys-ma@fintuvm.bitnet Date: Sun, 18 Feb 90 16:58:45 EET X-Mailer: ELM [version 2.2 PL10] Forwarded message: From I-AMIGA@finhutc.BITNET Sun Feb 18 13:04:55 1990 Message-Id: <9002181104.AA09742@mea.utu.fi> Date: Sun, 18 Feb 90 12:52:51 +0200 From: FINKEL@TAURUS.BITNET Subject: reboot a PAL machine into NTSC Sender: Info-Amiga List To: Matti Aarnio Reply-To: finkel@math.tau.ac.IL Comments: If you have trouble reaching this host as math.tau.ac.il Please use the old address: user@taurus.bitnet Comments: W: Field "Resent-From:/From:" duplicated. Last occurence was retained. Comments: W: Field "FROM:" duplicated. Last occurence was retained. X-To: comp-sys-amiga-tech@ucbvax.berkeley.edu, i-amiga@finhutc Hello everyone, This is a program I wrote last night to reboot a PAL machine into NTSC mode. You must have the new Agnus chip, and Kickstart 1.3 . The program relies on static location of certain Kickstart 1.3 ROM instructions, so it MUST be modified for Kickstart 1.2 . Are there any users of the new Agnus chip users with Kickstart 1.2?? The program has been tested on a PAL A500 with a super Agnus chip, a fully populated A590, Kickstart 1.3 ROM, and a Rev 3 motherboard hacked to contain the super Agnus chip. The program should work as is on 2000's as well, but I didn't test it. Again, it will *not* work with Kickstart 1.2 . The program can be easily modified to reboot an NTSC machine in PAL mode, but I remember reading that the american monitors can't work in PAL mode, while the european monitors can work in both modes. ( This was verified by me ;-) ). I could modify it to be more user-friendly ( find the appropriate address in the Kickstart ROM at run time, etc. ), but I was too lazy to do this ;-) ( actually, I had an exam the next morning so I didn't have too much time improving it ). Since our Usenet connection has been down for the last 3 weeks, any comments should be mailed to me directly, and not posted. Enjoy! ------------ cut ----------- cut ---------- cut ------------------- #! /bin/sh # This is a shell archive, meaning: # 1. Remove everything above the #! /bin/sh line. # 2. Save the resulting text in a file. # 3. Execute the file with /bin/sh (not csh) to create: # NTSCBoot.asm # NTSCBoot.uue # This archive created: Sun Feb 18 12:42:09 1990 export PATH; PATH=/bin:/usr/bin:$PATH echo shar: "extracting 'NTSCBoot.asm'" '(2487 characters)' if test -f 'NTSCBoot.asm' then echo shar: "will not over-write existing file 'NTSCBoot.asm'" else sed 's/^X//' << \SHAR_EOF > 'NTSCBoot.asm' X; X; NTSCBoot.asm X; X; Copyright (C) 1990 By Udi Finkelstein. X; 17 feb 1990 X; X; Reboot a SuperAgnus equipped PAL machine into NTSC mode. X; X; With thanks to Bart Whitebrook from CBM for his article on the new ECS X; registers in the 3rd european DevCon notes! X X; get into supervisor state, since we can only execute RESET there. X xref _LVOSuperState X move.l 4,a6 X jsr _LVOSuperState(a6) X X; ************************************ X; Warning!!! a grand hack ahead!!!!!!! X; Never do this stuff alone at home!!! X; ************************************ X X; Now we are in supervisor mode, and can issue a RESET command. X; Unfortunately, after RESET there is no RAM in the system! X; We can issue exacly *one* instruction ( 1 word length ) because X; the instruction was fetched before RESET was executed. This X; instruction can be a 'jmp (aX)', to somewhere on the ROM, where the X; program can continue. After searching the Kickstart 1.3 ROM, I found X; that at address $ff4120 you can find the code: X X; [ Notice - for Kickstart 1.3 ***ONLY***!!! Is there anybody out there X; with a Kickstart 1.2/super Agnus combination? you have a problem! ;-) ] X X;00FF4120 2741 0038 move.l d1,$38(a3) X;00FF4124 4281 clr.l d1 X;00FF4126 4ED6 jmp (a6) X X; We can use this code fragment to set the NTSC bit in the super agnus, X; and then jump to the reset code. The PAL/NTSC bit is contained in X; address $DFF1DC (BEAMCON0 !). X; X; 'move.l d1,$38(a3)' writes a longword, therefor $38(a3) must point to X; $dff1da because it's a read only location, which we can't harm, and X; $dff1dc contains the PAL/NTSC bit. X; $38(a3) == $dff1da --> a3 == $ddf1a2 X; we must reset d1 ofcourse, or set d1 == #$00000020 to set PAL mode. X; X; ofcourse we have to set a6 to $00000002 to run the reset code later. X; X XROMADR = ($ff4120-$fc0000) X X; ROMADR points to $ff4120 after the ROM appears in address $0000. X X lea.l $dff1a2,a3 X move.l #$0,d1 X move.l 2,a6 X cnop 0,4 X lea.l ROMADR,a5 X RESET ;reset the machine... X jmp (a5) ;execute our code fragment. X X; Well, that's it. I tried writing a more portable code by trying to X; set/reset the OVL bit in $BFE001 instead of 'jmp (aX)' after RESET, X; but I wasn't able to get it working, so the only way I found to run X; a code after RESET is to find a ROM fragment that happenes to match X; my requirement. You don't have to tell me how bad it is. Hopefully, X; the 1.4 preferences will have a PAL/NTSC software switch ( Will it?!!) X X END SHAR_EOF if test 2487 -ne "`wc -c < 'NTSCBoot.asm'`" then echo shar: "error transmitting 'NTSCBoot.asm'" '(should have been 2487 chara fi fi echo shar: "extracting 'NTSCBoot.uue'" '(133 characters)' if test -f 'NTSCBoot.uue' then echo shar: "will not over-write existing file 'NTSCBoot.uue'" else sed 's/^X//' << \SHAR_EOF > 'NTSCBoot.uue' X Xbegin 644 NTSCBoot XM```#\P`````````!```````````````(```#Z0````@L>``$3J[_:D?Y`-_Q0 X7HG(`+'@``DOY``-!($YP3M5.<0```_((_ X`` Xend Xsize 68 SHAR_EOF if test 133 -ne "`wc -c < 'NTSCBoot.uue'`" then echo shar: "error transmitting 'NTSCBoot.uue'" '(should have been 133 charac fi fi exit 0 # End of shell archive