gtBASIC

Using, learning, programming and modding the Gigatron and anything related.
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wbushby
Posts: 50
Joined: 16 Jul 2021, 10:59

Re: gtBASIC

Post by wbushby »

Neither set or get are working. same error

Assembler::assemble() : 'starraiders64k.gasm:3919' : invalid label/equate 'realTS_rti'
wbushby
Posts: 50
Joined: 16 Jul 2021, 10:59

Re: gtBASIC

Post by wbushby »

I am struggling with the sound in assembler. Best I could figure out for Channel 1 is this:

POKE 0x01FC, SX ' Frequency
POKE 0x01FE, SX + 10 ' Volume
POKE 0x2C, 255 ' Timer

But I get a short staccato sound.
at67
Posts: 389
Joined: 14 May 2018, 08:29

Re: gtBASIC

Post by at67 »

It doesn't work like that, it's more complicated :/

- Ignore xxFE and xxFF they are free running timers used by the audio subsytem.

- Frequency is a 15bit value, high byte into xxFD, low byte, (7bits shifted right once), into xxFC, xx = 01 to 04 for channel 1 to 4. If you want to skip the shift right of the low byte for sound effects you can, you only need the shift right for accurate musical notes, so DOKE xxFC, freq_15bit

- Volume is a 7bit value value between 127 and 64 for volume = 0 to 63, so POKE xxFA, (63-v) + 64.

- Wave type, (0 to 3, i.e. noise, triangle, square, ramp), so POKE xxFB, wave AND 3, higher values will modulate the signal for effects, you need to experiment).

- audio.i in gbas/runtime has assembly source code.
wbushby
Posts: 50
Joined: 16 Jul 2021, 10:59

Re: gtBASIC

Post by wbushby »

I had tried the code in audio.i but I am missing something.

Compiler::createAsmLine() : 'Main:6653' : vASM syntax error, undefined opcode : sndChannel EQU register8

Code: Select all

ENGINESOUND:

	asm
		sndChannel          EQU     register8
		sndFrequency        EQU     register9
		sndVolume           EQU     register10

		LDI     0xFC
        	ST      sndChannel
        	LD      _SX
        	SYS     48
        	ST      sndFrequency                    ; right shift low byte of sndFrequency by 1
        	LDW     sndFrequency                    ; format = high:8 low:07, (bit 7 of low byte = 0)
        	DOKE    sndChannel                      ; turn on channel
	endasm

	RET
at67
Posts: 389
Joined: 14 May 2018, 08:29

Re: gtBASIC

Post by at67 »

There's a few things wrong with your code:

1) Equates and labels have to start in the first column of the line otherwise they will be interpreted as opcodes, (that's why your equates are giving that error message).

2) The registerX equates are defined in gigatron.i, but you don't want to use the gtBASIC internal register vars in an interrupt routine as that is what causes the race conditions between the interrupt routine and gtBASIC, (use your own vars).

3) You are using SYS 48 on it's own, which will cause undefined behaviour depending on the contents of sysFn, (0x0022), you need to load sysFn first, then use SYS with the corresponding number of ticks for that sys function. So in your case if you want the right shift by 1 sys function, (SYS_LSRW1_48), then you need to pre-load sysFn and use sys in the following way:

Code: Select all

LDWI    SYS_LSRW1_48
STW     giga_sysFn
     .
     .
     .
SYS     48    ' shifts AC right by 1 bit
Here is a version of your code that has more chance to succeed: (*note* I didn't test this)

Code: Select all

' more accurate frequency version, (only needed for musical note accuracy)
ENGINESOUND_NOTE:
        sndVolAddr  = &h01FA                      ; channel 1, (out of 1 to 4)
        sndWaveAddr = &h01FB                      ; channel 1, (out of 1 to 4)
        sndFreqAddr = &h01FC                      ; channel 1, (out of 1 to 4)

        sndVol  = 96                              ; 127 to 64 -> 0 to 63 volume
        sndWave = 3                               ; wave type, (noise=0, triangle=1, square=2, ramp=3)
        sndFreq = 2000

	asm
                LDWI    SYS_LSRW1_48
                STW     giga_sysFn
                LD      _sndFreq                  ; use underscores when accessing gtBASIC vars in asm
                SYS     48
                ST      _sndFreq                  ; use underscores when accessing gtBASIC vars in asm
                LDW     _sndFreq                  ; format = high:8 low:07, (bit 8 of low byte = 0)
                DOKE    _sndFreqAddr              ; turn on channel
                LD      _sndVol
                POKE    _sndVolAddr
                LD      _sndWave
                POKE    _sndWaveAddr
	endasm
RET

' less accurate frequency version, (use for sound effects)
ENGINESOUND_FX:
        sndVolAddr  = &h01FA                      ; channel 1, (out of 1 to 4)
        sndWaveAddr = &h01FB                      ; channel 1, (out of 1 to 4)
        sndFreqAddr = &h01FC                      ; channel 1, (out of 1 to 4)

        sndVol  = 96                              ; 127 to 64 -> 0 to 63 volume
        sndWave = 3                               ; wave type, (noise=0, triangle=1, square=2, ramp=3)
        sndFreq = 2000

	asm
                LDW     _sndFreq                  ; format = high:8 low:07, (bit 8 of low byte = 0)
                DOKE    _sndFreqAddr              ; turn on channel
                LD      _sndVol
                POKE    _sndVolAddr
                LD      _sndWave
                POKE    _sndWaveAddr
	endasm
RET
wbushby
Posts: 50
Joined: 16 Jul 2021, 10:59

Re: gtBASIC

Post by wbushby »

Unfortunately that doesn't compile. just returns with no error message immediately.

gtbasic v1.0.9R


*******************************************************
* Compiling file './starraiders64k.gbas'
*******************************************************

C:\RetroComputors\Gigatron\gigatron-rom-master\gigatron-rom-master\Contrib\at67\gbas\classic\Test>


I copied the exact routine in as presented.
at67
Posts: 389
Joined: 14 May 2018, 08:29

Re: gtBASIC

Post by at67 »

Change all the semi-colons to single quotes, it's a parsing bug in your version of the compiler, I just tested this and it works:

Code: Select all

_runtimePath_ "../runtime"
_runtimeStart_ &h7FFF
_codeRomType_ ROMv3


repeat
    
    POKE &h2C, 255
    gosub ENGINESOUND_FX
forever


' less accurate frequency version, (use for sound effects)
ENGINESOUND_FX:
    sndVolAddr  = &h01FA                        ' channel 1, (out of 1 to 4)
    sndWaveAddr = &h01FB                        ' channel 1, (out of 1 to 4)
    sndFreqAddr = &h01FC                        ' channel 1, (out of 1 to 4)
    
    sndVol  = 64                                ' 127 to 64 -> 0 to 63 volume
    sndWave = 1                                 ' wave type, (noise=0, triangle=1, square=2, ramp=3)
    sndFreq = 12000

    asm
        LDW     _sndFreq                        ' format = high:8 low:07, (bit 8 of low byte = 0)
        DOKE    _sndFreqAddr                    ' turn on channel
        LD      _sndVol
        POKE    _sndVolAddr
        LD      _sndWave
        POKE    _sndWaveAddr
    endasm
RETURN
Last edited by at67 on 18 Sep 2021, 00:26, edited 1 time in total.
at67
Posts: 389
Joined: 14 May 2018, 08:29

Re: gtBASIC

Post by at67 »

Here's a slightly better example:

Code: Select all

_runtimePath_ "../runtime"
_runtimeStart_ &h7FFF
_codeRomType_ ROMv1


sndVolAddr  = &h01FA                        ' channel 1, (out of 1 to 4)
sndWaveAddr = &h01FB                        ' channel 1, (out of 1 to 4)
sndFreqAddr = &h01FC                        ' channel 1, (out of 1 to 4)

sndVol  = 64                                ' 127 to 64 -> 0 to 63 volume
sndWave = 2                                 ' wave type, (noise=0, triangle=1, square=2, ramp=3)
sndFreq = 5000
step = 300

repeat
    wait 1
    set SOUND_TIMER, 5                      ' enable all sound for 5 ticks, (>= 1 for this loop is fine)
    gosub DUMB_SIREN_FX:
    
    sndFreq = sndFreq + step
    if (sndFreq > 14000) OR (sndFreq < 1500) then step = -step
forever


' less accurate frequency version, (use for sound effects)
DUMB_SIREN_FX:
    asm
        LDW     _sndFreq                    ' format = high:8 low:07, (bit 8 of low byte = 0)
        DOKE    _sndFreqAddr                ' turn on channel
        LD      _sndVol
        POKE    _sndVolAddr
        LD      _sndWave
        POKE    _sndWaveAddr
    endasm
RETURN
wbushby
Posts: 50
Joined: 16 Jul 2021, 10:59

Re: gtBASIC

Post by wbushby »

I have been having one of those days. I completely missed the semi-colon
I also soldered a CPLD on turned 180 degrees today as well
wbushby
Posts: 50
Joined: 16 Jul 2021, 10:59

Re: gtBASIC

Post by wbushby »

I am just not getting this for some reason.

Compiler::createAsmLine() : 'Main:6668' : vASM syntax error, undefined opcode : LD _sndTime

Compiler::factor() : 'Main:6617' : found an unknown symbol 'LD _sndTime' : LD _sndTime

I don't see the difference between sndTime and sndFreq which works

Code: Select all

ENGINESOUND2:

	sndVolAddr  = &h01FA                      ' channel 1, (out of 1 to 4)
	sndWaveAddr = &h01FB                      ' channel 1, (out of 1 to 4)
	sndFreqAddr = &h01FC                      ' channel 1, (out of 1 to 4)
	sndTimer = &h2C

	sndVol  = 120                                ' 127 to 64 -> 0 to 63 volume
	sndWave = 0                                 ' wave type, (noise=0, triangle=1, square=2, ramp=3)
	sndFreq = 44
	sndTime = 255

    asm
        LDW     _sndFreq                    ' format = high:8 low:07, (bit 8 of low byte = 0)
        DOKE    _sndFreqAddr                ' turn on channel
        LD      _sndVol
        POKE    _sndVolAddr
        LD      _sndWave
        POKE    _sndWaveAddr
	LD		_sndTime
	POKE	_sndTimer
    endasm
RET
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