# Ami_Square_Wave.py # # DEMO to generate an audio tone from one of the classic AMIGA audio # channels, in this case a square wave. Almost any waveform is possible # and the Left Mouse Button is used to STOP this DEMO. # # MINIMUM Requirements Are:- # 68EC020 CPU and 2MB RAM total, example, a standard A1200(HD), # WinUAE and E-UAE. Standard AMIGA OS3.0x install or better. # Full Python 1.4.0, minimum, installed, can be found on AMINET. # (Python 1.5.2 to 2.0.x are also available on AMINET.) # (Now Python 2.4.6 is available for advanced 68K machines.) # # To install just download the file and drag this file into an Assign(ed) # PYTHON: volume... # From an AMIGA A1200(HD), E-UAE or WinUAE Python 1.4.0 prompt:- # # >>> execfile("PYTHON:Ami_Square_Wave.py") # # And away you go... # ========================================================================== # The DEMO assembly code that will be compiled and converted. # Call the code beep.asm... # From a CLI and using the a68k and blink from AMINET:- # # Prompt> a68k beep.asm # Some reports here... # Prompt> blink beep.o # Some reports here... # # This code is TOTALLY, even address, position independent. # ========================================================================== # start: # ;"beep.asm" test code... # movem.l d0-d7/a0-a6,-(sp) ;Save all registers just in case. # movea.l $4,a6 ;Set ~execbase~. # moveq #16,d0 ;Length of square wave data. # moveq #2,d1 ;Set to chip ram. # jsr -198(a6) ;Allocate memory for the task. # beq.s getout ;On error, Quit. # move.l d0,a0 ;Set address in chip ram. # move.l #$3f3f3f3f,(a0) ;Set first four bytes of sixteen. # addq.l #4,a0 ;Move addres by four. # move.l #$3f3f3f3f,(a0) ;Set next four bytes of sixteen. # addq.l #4,a0 ;Move addres by four. # move.l #$80808080,(a0) ;Set next four bytes of sixteen. # addq.l #4,a0 ;Move addres by four. # move.l #$80808080,(a0) ;Set last four bytes of sixteen. # ;This ensures absolute position # ;independence. # lea $dff000,a5 ;Set HW register base. # move.w #$000f,$96(a5) ;Disable audio DMA. # move.l d0,$a0(a5) ;Set address of audio data. # move.w #8,$a4(a5) ;Set length in words. # move.w #64,$a8(a5) ;Set volume to maximum. # move.w #220,$a6(a5) ;Set the period. # move.w #$00ff,$9e(a5) ;Disable any modulation. # move.w #$8201,$96(a5) ;Enable audio DMA, 1 channel only. # wait: # btst #6,$bfe001 ;If LMB pressed then Quit. # beq.s closeme ;Do it. # bne.s wait ;Play the tone until LMB pressed... # closeme: # move.w #$000f,$96(a5) ;Disable audio DMA. # move.l d0,a0 ;Address of the square wave data. # moveq #16,d0 ;The data length to recover. # jsr -210(a6) ;Free assigned memory. # getout: # movem.l (sp)+,d0-d7/a0-a6 ;Restore all registers. # clr.l d0 ;Set returm code OK. # rts # nop # even # end # ========================================================================== # The text HEX file to be edited for the Python code:- # # Prompt> Type HEX beep > beep.hex # # Gives a text file "beep.hex" that has the contents:- # ========================================================================== # 0000: 000003F3 00000000 00000001 00000000 ...ó............ # 0010: 00000000 00000021 000003E9 00000021 .......!...é...! # 0020: 48E7FFFE 2C780004 70107202 4EAEFF3A Hç.þ,x..p.r.N®.: # 0030: 67682040 20BC3F3F 3F3F5888 20BC3F3F gZ @ Œ????X. Œ?? # 0040: 3F3F5888 20BC8080 80805888 20BC8080 ??X. Œ....X. Œ.. # 0050: 80804BF9 00DFF000 3B7C000F 00962B40 ..Kù.ßð.;|....+@ # 0060: 00A03B7C 000800A4 3B7C0040 00A83B7C . ;|...€;|.@.š;| # 0070: 00DC00A6 3B7C00FF 009E3B7C 82010096 .Ü.Š;|....;|.... # 0080: 08390006 00BFE001 670266F4 3B7C000F .9...¿à.g.fô;|.. # 0090: 00962040 70104EAE FF2E4CDF 7FFF4280 .. @p.N®..Lß..B. # 00A0: 4E754E71 000003F2 NuNq...ò # ========================================================================== # With careful manipulation of the Python code you could have control of the # audio levels, channels, frequency, etc, using this method... # # Enjoy finding simple solutions to often very difficult problems... # # $VER: Ami_Square_Wave.py_Version_0.00.30_(C)2007-2011_B.Walker_G0LCU. # # Original copyright, (C)2007-2011, B.Walker, G0LCU. Now finally issued as Public Domain. import os # Manually place the executable code into practical binary string lengths. one="\x00\x00\x03\xF3\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x21\x00\x00" two="\x03\xE9\x00\x00\x00\x21\x48\xE7\xFF\xFE\x2C\x78\x00\x04\x70\x10\x72\x02\x4E\xAE\xFF\x3A\x67\x68\x20\x40\x20\xBC" wave="\x3F\x3F\x3F\x3F\x58\x88\x20\xBC\x3F\x3F\x3F\x3F\x58\x88\x20\xBC\x80\x80\x80\x80\x58\x88\x20\xBC\x80\x80\x80\x80" three="\x4B\xF9\x00\xDF\xF0\x00\x3B\x7C\x00\x0F\x00\x96\x2B\x40\x00\xA0\x3B\x7C\x00\x08\x00\xA4\x3B\x7C\x00" volume="\x40" four="\x00\xA8\x3B\x7C\x00\xDC\x00\xA6\x3B\x7C\x00\xFF\x00\x9E\x3B\x7C\x82\x01\x00\x96\x08\x39\x00\x06\x00\xBF" five="\xE0\x01\x67\x02\x66\xF4\x3B\x7C\x00\x0F\x00\x96\x20\x40\x70\x10\x4E\xAE\xFF\x2E\x4C\xDF\x7F\xFF\x42\x80" six="\x4E\x75\x4E\x71\x00\x00\x03\xF2" # Clear the screen the standard AMIGA way... ;o) print "\f" # A simple user screen... print "1 KHz Square Wave Generator for the classic AMIGA A1200." print "Using standard text mode Python 1.4.0 to 2.0.1.\n" print "(C)2007-2011, B.Walker, GOLCU. Issued as Public Domain...\n" # Show how to change output, (volume), level... vol=raw_input("Set output level, 0 to 64:- ") # Don't allow any errors... if vol=="": vol="64" if len(vol)>=3: vol="64" count=0 while count<=(len(vol)-1): if vol[count]>=chr(48) and vol[count]<=chr(57): count=count+1 else: vol="64" if eval(vol)>=64: vol="64" if eval(vol)<=0: vol="0" volume=chr(eval(vol)) # Put them all together as a single binary string. amiga_exe_file=one+two+wave+three+volume+four+five+six # Generate a file called SquareWave inside the S: VOLUME and write to the disk. amigafile=open("S:SquareWave","wb+") amigafile.write(amiga_exe_file) amigafile.close() # Give a short delay to allow system to settle. os.system("C:Wait 1") print "\nPress Left Mouse Button to stop...\n" # Ensure the file SquareWave can be executed. os.system("C:Protect S:SquareWave rwed") # Now run it. os.system("S:SquareWave") print "This DEMO has now stopped..." # Ami_Square_Wave.py end... # Enjoy finding simple solutions to often very difficult problems.