PsL Monthly 1993 December/PSL Monthly Shareware CD-ROM (December 1993).iso/prgmming/dos/tools/dvpt2.exe/VPMOD.ASM

Assembly Source File | 1991-12-12 | 16.1 KB | 763 lines

page 58,132
;****************************************************************
;*                                                              *
;*             Digitized Voice Programmer's Toolkit             *
;*             ------------------------------------             *
;*                                                              *
;*                  Sound Playback Primitives                   *
;*                                                              *
;*            Copyright (c) 1991, Farpoint Software             *
;*                                                              *
;****************************************************************

.8086
.MODEL LARGE

;**********************************************************************
;*                                                                    *
;*                             Equates                                *
;*                                                                    *
;**********************************************************************

tccount        equ    72    ;reload count to produce 16572 Hz
countmax_18hz    equ    910    ;ratio of new timer rate to standard rate

tcaddrc        equ    43h    ;timer/counter control register address
tcaddrd0    equ    40h    ;timer/counter data register zero (sys clock)
tcaddrd2    equ    42h    ;timer/counter data register two (spkr)

tcmode0a    equ    34h    ;two-byte mode for system clock timer
tcmode0b    equ    24h    ;high-byte mode for system clock timer
tcmode2a    equ    0B0h    ;mode for speaker timer (for initialization)

tclatchcmd0    equ    00h    ;latch command for reading timer 0
tclatchcmd2    equ    80h    ;latch command for reading timer 2

ppiaddr        equ    61h    ;programmable peripheral interface address

kbdonly_mask    equ    0FDh    ;mask config to allow only keyboard interrupt
intmaskaddr    equ    21h    ;address of the interrupt mask register
kbdint_number    equ    9    ;vector number of the keyboard hardware int

;CPU speed calibration initialization parameters

init_delayctr        equ    1024
init_cal_increment    equ    512
init_cal_passes        equ    10

;**********************************************************************
;*                                                                    *
;*                         Global variables                           *
;*                                                                    *
;**********************************************************************

.DATA

;CPU speed calibration data

delayctr    dw    init_delayctr-1
cal_increment    dw    init_cal_increment
cal_passes    dw    init_cal_passes

;keyboard hardware interrupt occurrence flag

keyflag        db    0

;interrupt controller mask save byte

original_mask    db    0

;port 61h default configuration

ppibyte        db    0

;**********************************************************************
;*                                                                    *
;*                               Code                                 *
;*                                                                    *
;**********************************************************************

.CODE

    assume    ds:DGROUP

;code-segment storage for keyboard interrupt chain vector

original_kbdint_vec    dd    0

;**********************************************************************
;*          Keyboard Hardware Interrupt Intercept Routine             *
;**********************************************************************

;This routine sets the "keyflag" variable to 1 whenever a keyboard
; interrupt occurs.

kbdint    proc    far

    push    ds
    push    ax
    mov    ax,DGROUP
    mov    ds,ax
    mov    keyflag,1
    pop    ax
    pop    ds
    jmp    dword ptr cs:original_kbdint_vec

kbdint    endp

;**********************************************************************
;*              Calibrated software delay routine                     *
;**********************************************************************

;lots of nops

delay    proc    near

    db    init_delayctr dup (90h)
    ret                ;starting delay value
    db    (init_delayctr-1) dup (90h)
    ret                ;should never actually be executed

delay    endp

;**********************************************************************
;*         Initialize timer for correct speaker operation.            *
;**********************************************************************

;This procedure returns 0 if successful and 1 if unsuccessful.

set_ppibyte    proc    near

;return value is kept in BX register

    mov    bx,0        ;set to 1 later if required

;set gate 2 drive to one

    in    al,ppiaddr
    and    al,0FDh
    or    al,01h
    mov    ppibyte,al
    out    ppiaddr,al

;set timer chip to mode zero (int on terminal count)

    mov    al,tcmode2a
    cli
    out    tcaddrc,al
    jmp    short $+2
    jmp    short $+2

;set count to 0001h for quick termination

    mov    al,1
    out    tcaddrd2,al
    jmp    short $+2
    jmp    short $+2
    sub    al,al
    out    tcaddrd2,al
    sti
    jmp    short $+2
    jmp    short $+2

;write the standard setup to timer zero

    mov    al,tcmode0a
    cli
    out    tcaddrc,al
    jmp    short $+2
    jmp    short $+2
    mov    al,0
    out    tcaddrd0,al
    jmp    short $+2
    jmp    short $+2
    out    tcaddrd0,al
    sti
    jmp    short $+2
    jmp    short $+2

;set timer zero to high-byte mode

    mov    al,tcmode0b
    cli
    out    tcaddrc,al
    jmp    short $+2
    jmp    short $+2
    mov    al,0
    out    tcaddrd0,al
    sti
    jmp    short $+2
    jmp    short $+2

;wait for next timer tick

    mov    ah,0
    mov    al,tclatchcmd0
    cli
    out    tcaddrc,al
    jmp    short $+2
    jmp    short $+2
    in    al,tcaddrd0
    sti
    jmp    short $+2
    jmp    short $+2
    mov    dx,ax
spi_sync:
    mov    al,tclatchcmd0
    cli
    out    tcaddrc,al
    jmp    short $+2
    jmp    short $+2
    in    al,tcaddrd0
    sti
    jmp    short $+2
    cmp    ax,dx
    mov    dx,ax
    jbe    spi_sync

;Wait for another timer tick (18Hz); this should be
; plenty of time for timer 2 to reach terminal count.

spi_wt1:
    mov    al,tclatchcmd0
    cli
    out    tcaddrc,al
    jmp    short $+2
    jmp    short $+2
    in    al,tcaddrd0
    sti
    sub    ah,ah
    cmp    ax,dx
    mov    dx,ax
    jbe    spi_wt1

;read the content of timer 2 and check for 0001h

    mov    al,tclatchcmd2
    cli
    out    tcaddrc,al
    jmp    short $+2
    jmp    short $+2
    in    al,tcaddrd2
    mov    ah,al
    jmp    short $+2
    jmp    short $+2
    in    al,tcaddrd2
    sti
    or    al,al        ;test high byte for 00h
    jnz    spi_countdone
    cmp    ah,1        ;test low byte for 01h
    jnz    spi_countdone

;(arrive here if timer 2 is NOT counting)
;If timer 2 does not count,
; we flag an error and keep going.

    mov    bx,1

;set gate 2 drive to zero (disable counting)

spi_countdone:
    in    al,ppiaddr
    and    al,0FCh
    mov    ppibyte,al
    out    ppiaddr,al

;count is (supposedly) finished; test timer 2 output readback bit

    in    al,ppiaddr
    test    al,20h        ;bit 5 should be high
    jnz    spi_done

;wrong polarity, set error flag and continue

    mov    bx,1

spi_done:
    mov    ax,bx
    ret

set_ppibyte    endp

;**********************************************************************
;*                    Set Calibration Constant                        *
;*                                                                    *
;*       This call simply sets the calibration constant to the        *
;*       value specified in the parameter.                            *
;**********************************************************************

;Accepts the following parameters with PASCAL parameter-passing convention:

;Position   Size   Description
;--------   ----   -----------
;   1         2    The calibration constant to be set.

;There is no return value.

psc_parm1    equ    [bp+6]    ;length = 2

psc_parmlength    equ    2

    public    PSETCAL

PSETCAL        proc    far

    push    bp
    mov    bp,sp

;in case this routine has been called before, erase the "ret" instruction
; that was placed in the delay routine

    inc    delayctr        ;since we decremented it before
    lea    bx,delay
    add    bx,delayctr
    mov    byte ptr cs:[bx],90h    ;this is a "nop" instruction

;get the new delay parameter

    mov    ax,psc_parm1
    mov    delayctr,ax

;insert a "ret" instruction at the new location in the delay routine

    lea    bx,delay
    add    bx,delayctr
    mov    byte ptr cs:[bx],0C3h    ;this is a "ret" instruction

    dec    delayctr        ;for benefit of playback routine

    pop    bp
    ret    psc_parmlength

PSETCAL        endp

;**********************************************************************
;*                      Calibration procedure                         *
;*                                                                    *
;*      This routine must be called once before any calls are made    *
;*      to the playback routine. It measures the CPU execution        *
;*      speed and saves compensation values.                          *
;**********************************************************************

;There are no entry parameters.

;The return value is a double word, defined as follows:

;Return value low word        Meaning
;---------------------        -------
;     0                       success
;     1                       this CPU is too slow to accomplish
;                              normal-speed playback
;     2                       operation not possible under Windows
;                              in "Enhanced" mode
;     3                       unusual speaker drive circuit encountered,
;                              might not output sound

;The return value high word is the actual speed calibration constant
; for this computer

cal_temp1    equ    [bp-2]    ;length = 2

cal_locallength    equ    2

    public    PCALIBRATE

PCALIBRATE    proc    far

    push    bp
    mov    bp,sp
    sub    sp,cal_locallength
    push    si
    push    di

;test for the "Enhanced Mode Windows" environment

    mov    ax,1600h
    int    2Fh
    cmp    al,00h
    je    cal_no_enh_win
    cmp    al,80h
    je    cal_no_enh_win
    mov    delayctr,1
    mov    ax,2
    jmp    cal_exit
cal_no_enh_win:

;test speaker drive circuitry and set configuration

    call    set_ppibyte
    mov    cal_temp1,ax

;in case this routine has been called before, erase the "ret" instruction
; that was placed in the delay routine

    inc    delayctr        ;since we decremented it before
    lea    bx,delay
    add    bx,delayctr
    mov    byte ptr cs:[bx],90h    ;this is a "nop" instruction

;initialize parameters

    mov    delayctr,init_delayctr
    mov    cal_increment,init_cal_increment
    mov    cal_passes,init_cal_passes

;insert a "ret" instruction into the starting location in the delay routine

    lea    bx,delay
    add    bx,delayctr
    mov    byte ptr cs:[bx],0C3h    ;this is a "ret" instruction

;no interrupts until we are through calibrating

    cli

;write the standard setup to timer zero

    mov    al,tcmode0a
    out    tcaddrc,al
    jmp    short $+2
    jmp    short $+2
    mov    al,0
    out    tcaddrd0,al
    jmp    short $+2
    jmp    short $+2
    out    tcaddrd0,al
    jmp    short $+2
    jmp    short $+2

;set timer zero to high-byte mode

    mov    al,tcmode0b
    out    tcaddrc,al
    jmp    short $+2
    jmp    short $+2
    mov    al,0
    out    tcaddrd0,al
    jmp    short $+2
    jmp    short $+2

;initialize loop count

cal_zerocnt:
    sub    cx,cx

;synchronize to timer tick

    mov    ah,0
    mov    al,tclatchcmd0
    out    tcaddrc,al
    jmp    short $+2
    jmp    short $+2
    in    al,tcaddrd0
    jmp    short $+2
    jmp    short $+2
    mov    si,ax
cal_sync:
    mov    al,tclatchcmd0
    out    tcaddrc,al
    jmp    short $+2
    jmp    short $+2
    in    al,tcaddrd0
    jmp    short $+2
    cmp    ax,si
    mov    si,ax
    jbe    cal_sync

;calibration loop

cal_dummyloop:
    mov    al,80h
    nop
    nop
    or    ax,ax
    jz    cal_scale
cal_scale:
    sub    ah,ah
    mov    bx,1        ;dummy value
    mul    bx
    mov    al,ah
    mov    ah,dl
    lea    bx,delay
    add    bx,ax
    mov    word ptr cs:[bx],9090h    ;these are "nop" instructions
    mov    al,ppibyte
    or    al,00h
    out    ppiaddr,al
    and    al,0FFh
    call    delay
    mov    word ptr cs:[bx],9090h    ;these are "nop" instructions
    inc    cx
    mov    al,tclatchcmd0
    out    tcaddrc,al
    jmp    short $+2
    jmp    short $+2
    in    al,tcaddrd0
    sub    ah,ah
    nop
    nop
    cmp    ax,si
    mov    si,ax
    nop
    nop
    jbe    cal_dummyloop

;kill the old "ret" instruction in the delay routine

    lea    bx,delay
    add    bx,delayctr
    mov    byte ptr cs:[bx],90h    ;this is a "nop" instruction

;adjust delay counter

    mov    ax,cal_increment
    shr    cal_increment,1
    cmp    cx,countmax_18hz
    je    cal_setret
    jb    cal_makefaster
    add    delayctr,ax
    jmp    cal_setret
cal_makefaster:
    sub    delayctr,ax
cal_setret:                ;here we insert a new return
    lea    bx,delay
    add    bx,delayctr
    mov    byte ptr cs:[bx],0C3h    ;this is a "ret" instruction
    dec    cal_passes
    cmp    cal_passes,0
    je    cal_restore
    jmp    cal_zerocnt

;repair loss of system timer ticks and restore interrupts

cal_restore:
    mov    bx,40h
    mov    es,bx
    mov    bx,6Ch
    add    word ptr es:[bx],init_cal_passes+1
    adc    word ptr es:[bx+2],0
    cmp    word ptr es:[bx+2],18h
    jb    cal_tc_end
    ja    cal_tc_midnite
    cmp    word ptr es:[bx],0B0h
    jb    cal_tc_end
cal_tc_midnite:
    mov    byte ptr es:[bx+4],1
    sub    word ptr es:[bx],0B0h
    sbb    word ptr es:[bx+2],18h
cal_tc_end:
    sti

;determine if CPU is too slow

    dec    delayctr        ;for benefit of playback routine
    cmp    delayctr,64
    jb    cal_cpuslow
    sub    ax,ax
    jmp    cal_exit
cal_cpuslow:
    mov    ax,1
cal_exit:
    or    ax,ax
    jnz    cal_rdc
    cmp    word ptr cal_temp1,0
    jz    cal_rdc
    mov    ax,3
cal_rdc:
    mov    dx,delayctr
    pop    di
    pop    si
    add    sp,cal_locallength
    pop    bp
    ret

PCALIBRATE    endp

;**********************************************************************
;*                        Playback procedure                          *
;**********************************************************************

;Accepts the following parameters with PASCAL parameter-passing convention:

;Position   Size   Description
;--------   ----   -----------
;   1         4    A far pointer to the memory block used for voice data.
;   2         4    A dword indicating the length of the memory block.

;The return value is a dword indicating the number of bytes actually played.

pv_parm1    equ    [bp+10]    ;length = 4
pv_parm2_hi    equ    [bp+8]    ;length = 2
pv_parm2_lo    equ    [bp+6]    ;length = 2

pv_parmlength    equ    8

pv_temp1    equ    [bp-2]    ;length = 2
pv_temp2    equ    [bp-4]    ;length = 2

pv_locallength    equ    4

    public    PLAYVOICE

PLAYVOICE    proc    far

    push    bp
    mov    bp,sp
    sub    sp,pv_locallength
    push    si
    push    di

;setup speaker and timer 2

    call    set_ppibyte

;mask all interrupts except the keyboard

    cli

    in    al,intmaskaddr
    mov    original_mask,al
    mov    al,kbdonly_mask
    out    intmaskaddr,al

;install the keyboard interrupt intercept routine

    sub    ax,ax
    mov    es,ax
    mov    bx,kbdint_number*4
    mov    ax,es:[bx]
    mov    word ptr cs:original_kbdint_vec,ax
    mov    ax,es:[bx+2]
    mov    word ptr cs:original_kbdint_vec+2,ax
    lea    ax,kbdint
    mov    es:[bx],ax
    mov    ax,cs
    mov    es:[bx+2],ax

    sti

;set up initial conditions

    mov    keyflag,0
    les    si,dword ptr pv_parm1
    mov    cx,pv_parm2_lo
    mov    di,pv_parm2_hi
    jcxz    pv_playloop
    inc    di

;playback loop

pv_playloop:
    mov    al,es:[si]
    inc    si
    jz    pv_incrseg
pv_scale:
    sub    ah,ah
    mov    bx,delayctr
    mul    bx
    mov    al,ah
    mov    ah,dl
    lea    bx,delay
    add    bx,ax
    mov    word ptr cs:[bx],61E6h    ;this is an "out 61h,al" instruction
    mov    al,ppibyte
    or    al,02h
    out    ppiaddr,al
    and    al,0FDh
    call    delay
    mov    word ptr cs:[bx],9090h    ;these are "nop" instructions
    nop
    mov    al,tclatchcmd0
    out    tcaddrc,al
    jmp    short $+2
    jmp    short $+2
    in    al,tcaddrd0
    sub    ah,ah
    cmp    keyflag,0
    jne    pv_stop
    loop    pv_playloop
    dec    di
    jnz    pv_playloop
pv_stop:
    jmp    short pv_fixkbi

pv_incrseg:
    mov    bx,es
    add    bx,1000h
    mov    es,bx
    jmp    short pv_scale

;remove the keyboard interrupt intercept routine

pv_fixkbi:
    cli

    sub    ax,ax
    mov    es,ax
    mov    bx,kbdint_number*4
    mov    ax,word ptr cs:original_kbdint_vec
    mov    es:[bx],ax
    mov    ax,word ptr cs:original_kbdint_vec+2
    mov    es:[bx+2],ax

;restore the original interrupt mask

    mov    al,original_mask
    out    intmaskaddr,al

    sti

;leave speaker in a known state

    mov    al,ppibyte
    out    ppiaddr,al

;calculate the number of bytes played

    jcxz    pv_calcbytes
    dec    di
pv_calcbytes:
    mov    ax,pv_parm2_lo
    mov    dx,pv_parm2_hi
    sub    ax,cx
    sbb    dx,di
    mov    pv_temp2,ax
    mov    pv_temp1,dx

;compensate for lost timer ticks

    mov    cx,countmax_18hz
    div    cx
    mov    bx,40h
    mov    es,bx
    mov    bx,6Ch
    cli
    add    es:[bx],ax
    adc    word ptr es:[bx+2],0
    cmp    word ptr es:[bx+2],18h
    jb    pv_tc_end
    ja    pv_tc_midnite
    cmp    word ptr es:[bx],0B0h
    jb    pv_tc_end
pv_tc_midnite:
    mov    byte ptr es:[bx+4],1
    sub    word ptr es:[bx],0B0h
    sbb    word ptr es:[bx+2],18h
pv_tc_end:
    sti

;set the return value

    mov    ax,pv_temp2
    mov    dx,pv_temp1

    pop    di
    pop    si
    add    sp,pv_locallength
    pop    bp
    ret    pv_parmlength

PLAYVOICE    endp

    end