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Simtel MSDOS 1992 September
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DIMMER.ASM
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Assembly Source File
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1989-06-20
|
33KB
|
716 lines
page 66,132
;============================================================================
; DIMMER.COM allows VGA users to interactively brighten or dim the screen.
; Syntax is:
;
; DIMMER [/U] [/V[+|-]] [/D mmm [+|-]xx] [[+|-]xx]
;
; where /U = Uninstall the program
; /D = Adjust intensity by xx after mmm minutes of inactivity
; xx = Numeric code from -63 to +63 representing relative
; amount by which to adjust the intensity
; /V = Reset delay timer on call to BIOS video interrupt. The
; default is V-.
;
; COMMAND LINE INTENSITY CONTROL
;
; DIMMER /D 1 -63 causes the screen to blank after 1 minute of
; inactivity. DIMMER /D 0 cancels any time delay previously entered.
; DIMMER -20 causes the screen to immediately dim 20 intensity levels.
; DIMMER 0 restores the screen intensity to what it was when DIMMER
; was installed. In all cases, DIMMER becomes RAM-resident so that
; intensity levels can also be adjusted interactively.
; DIMMER /D 1 -63 /V causes the screen to blank after 1 minute of
; inactivity. If a program calls any BIOS video routines, the
; screen is reset to its original brightness.
;
; INTERACTIVE INTENSITY CONTROL
;
; With DIMMER installed, Alt-UpArrow increases the display intensity
; by 1 level, Alt-DnArrow decreases the intensity by 1 level, and
; Alt-Home restores the screen intensity to what it was when DIMMER
; was installed.
;============================================================================
code segment
assume cs:code
org 2Ch
env_segment dw ? ;Address of environment block
org 80h
command_tail dw ? ;Address of command tail
org 100h
main: jmp initialize ;Go to initialization code
program db "Dimmer 1.0 "
copyright db "(c) 1989 Ziff Communications Co.",13,10
authors db "PC Magazine ",254," Doug Boling and Jeff Prosise"
db "$",1Ah
dimmer_val db 0 ;Relative dimmer value
delaydimval db 0 ;Delayed dimmer value
wait_time dw -1 ;Delay until screen blank
dim_counter dw -1 ;Number of minutes to delay
second_cnt dw 1092 ;Timer ticks per minute
restorebyvid db 0 ;1 = delay reset by video call
vid_function dw 0 ;Saved video function
int08h dd ? ;Int 8 vector (Timer)
int09h dd ? ;Int 9 vector (Keyboard)
int10h dd ? ;Int 10 vector (Video)
;============================================================================
; TIMERINT services the BIOS timer interrupt.
;============================================================================
timerint proc far
pushf ;Push flags
call int08h ;Call BIOS timer routine
sti ;Enable interrupts
push ax ;Save AX
mov ax,cs:[dim_counter] ;Get delay counter
cmp ax,0FFFFh ;See if timer enabled
je timer_exit ;Exit if not enabled
or ax,ax ;Exit if timer at 0 to
je timer_exit ; prevent rollover.
dec cs:[second_cnt] ;Decrement seconds and exit
jnz timer_exit ; if not zero
mov word ptr cs:[second_cnt],1092
dec ax ;Decrement minute counter
mov cs:[dim_counter],ax ;Update delay counter
or ax,ax ;Exit if timer hasn't
jne timer_exit ; reached zero
mov ah,cs:[delaydimval] ;Get dimmer value
call adj_palette_2 ;Modify color registers
timer_exit:
pop ax ;Restore AX and exit
iret
timerint endp
;============================================================================
; KBINT services the keyboard interrupt.
;============================================================================
kbint proc far
sti ;Enable interrupts
push ax ;Save AX
mov cs:[second_cnt],1092 ;Reset delay counters
mov ax,cs:[wait_time]
xchg cs:[dim_counter],ax
or ax,ax ;If counter was 0, reset the
jne kbint0 ; screen intensity
mov ah,cs:[dimmer_val]
call adj_palette_2
kbint0:
push ds ;Save DS
mov ax,40h ;Point DS to BIOS data area
mov ds,ax
mov al,ds:[17h] ;Get keyboard shift status
pop ds ;Restore DS
and al,0Fh ;Mask upper 4 bits
cmp al,8 ;Check for Alt key
je alt_found ;Continue if Alt is pressed
goto_bios:
pop ax ;Restore AX and exit to
jmp int09h ; BIOS keyboard handler
alt_found:
in al,60h ;Get key pressed
cmp al,72 ;Check for UpArrow
jne kbint1
cmp cs:[dimmer_val],63 ;Increment color registers
jge kbint3 ; by 1 if dimmer value
inc cs:[dimmer_val] ; isn't maxed out
jmp short kbint3
kbint1:
cmp al,80 ;Check for DnArrow
jne kbint2
cmp cs:[dimmer_val],-63 ;Decrement color registers
jle kbint3 ; by 1 if dimmer value
dec cs:[dimmer_val] ; isn't zeroed out
jmp short kbint3
kbint2:
cmp al,71 ;Reset color registers if
jne goto_bios ; Alt-Home was pressed
mov cs:[dimmer_val],0
kbint3:
mov ah,cs:[dimmer_val] ;Get dimmer value
call adj_palette_2 ;Modify color registers
cli ;Disable interrupts
in al,61h ;Reset the keyboard
mov ah,al ; controller
or al,80h
out 61h,al
mov al,ah
out 61h,al
mov al,20h ;Signal end-of-interrupt to
out 20h,al ; the interrupt controller
sti ;Enable interrupts
pop ax ;Restore AX and exit
iret
kbint endp
;============================================================================
; VIDEOINT services the BIOS video interrupt.
;============================================================================
videoint proc far
mov cs:[vid_function],ax ;Save function number
pushf ;Push flags
call int10h ;Call video BIOS routine
sti ;Enable interrupts
push ax ;Save AX
cmp cs:[restorebyvid],0 ;If video checking enabled,
je video_1 ; check delay counter.
cmp word ptr cs:[dim_counter],0
jne video_1 ;Restore color register
mov ah,cs:[dimmer_val] ; values if timed delay
call adj_palette_2 ; has dimmed the screen
mov cs:[second_cnt],1092 ;Reset delay counters
mov ax,cs:[wait_time]
mov cs:[dim_counter],ax
video_1:
mov ax,cs:[vid_function] ;See what function was called
or ah,ah ;Check for mode change
je refresh_palette
cmp ah,11h ;Check for mode reset
je refresh_palette
cmp ax,1010h ;Check for changes to the
je refresh_buffer ; VGA color registers
cmp ax,1012h ; made thru the video
je refresh_buffer ; BIOS
cmp ax,101Bh
jne video_exit
refresh_buffer:
call get_palette ;Reload register array
jmp short video_exit
refresh_palette:
mov ah,cs:[dimmer_val] ;Get dimmer adjust value
call adj_palette_2 ;Modify palette
video_exit:
pop ax ;Restore AX and exit
iret
videoint endp
;----------------------------------------------------------------------------
; ADJ_PALETTE_1 adjusts the VGA color registers to their original values
; plus the current dimmer value.
; Entry: AH - Dimmer value
; DS - Segment where color register values are stored
;----------------------------------------------------------------------------
adj_palette_1 proc near
cld ;Clear direction flag
push cx ;Save registers
push dx
push si
mov si,offset end_res ;Point SI to buffer
; containing original values
mov dx,03C8h ;Write address register
xor al,al ;Set beginning address
cli ;Disable interrupts
out dx,al
mov cx,256 * 3 ;256 color registers
mov dx,03C9h ;Write data register
adj_loop1:
lodsb ;Get color value
call mod64_add ;Add dimmer value
out dx,al ;Write data to color register
loop adj_loop1 ;Loop until done
sti ;Enable interrupts
pop si ;Restore registers and exit
pop dx
pop cx
ret
adj_palette_1 endp
;----------------------------------------------------------------------------
; ADJ_PALETTE_2 adjusts the VGA color registers to their original values
; plus the current dimmer value.
; Entry: AH - Dimmer value
;----------------------------------------------------------------------------
adj_palette_2 proc near
push ds ;Save DS
push cs ;Point DS to code segment
pop ds
call adj_palette_1 ;Modify color registers
pop ds ;Restore DS and exit
ret
adj_palette_2 endp
;----------------------------------------------------------------------------
; MOD64_ADD adds AH to AL using modulo 64 math.
;----------------------------------------------------------------------------
mod64_add proc near
or al,al ;If 0, don't brighten
je mod2
add al,ah
cmp al,0 ;See if underflow
jg mod1
mov al,0 ;If so, set at minimum
jmp short mod2
mod1:
cmp al,63 ;See if overflow
jbe mod2
mov al,63 ;If so, set at maximum
mod2:
ret
mod64_add endp
;----------------------------------------------------------------------------
; GET_PALETTE buffers the current values of the VGA color registers.
;----------------------------------------------------------------------------
get_palette proc near
cld ;Clear direction flag
push ax ;Save registers
push cx
push dx
push di
push es
mov cx,cs ;Point ES to the code segment
mov es,cx
mov di,offset end_res ;Point DI to save buffer
mov dx,03C7h ;Read address register
xor al,al ;Begin with register 0
cli ;Disable interrupts
out dx,al
mov cx,256 * 3 ;256 color registers
mov dx,03C9h ;Read data register
getp_loop1:
in al,dx ;Get color register value
and al,3Fh ;Mask off the upper 2 bits
stosb ;Store it
loop getp_loop1 ;Loop until done
sti ;Enable interrupts
pop es ;Restore registers and exit
pop di
pop dx
pop cx
pop ax
ret
get_palette endp
;----------------------------------------------------------------------------
; FINAL_INSTALL is the last of the resident code.
;----------------------------------------------------------------------------
final_install:
assume ds:code
call get_palette ;Get color register values
mov ah,dimmer_val ;Adjust color registers and
call adj_palette_2 ; terminate
mov dx,(offset end_res-offset code+768+15) SHR 4
mov ax,3100h
int 21h
end_res = $ ;End of resident code
;============================================================================
; Start of non-resident section.
;============================================================================
alrdy_installed db 0 ;Installed flag
other_seg dw 0 ;Segment of installed code
change_flag db 0 ;Set if dimmer or delay
; value is modified
infomsg1 db "Program uninstalled$"
errmsg1 db "Program not installed$"
errmsg2 db "Syntax: DIMMER [/U] [/V[+|-]] [/D mmm [+|-]xx]"
db " [[+|-]xx]$"
errmsg3 db "Can",39,"t uninstall$"
errmsg4 db "VGA required$"
errmsg5 db "Intensity value must be between -63 and +63$"
errmsg6 db "Invalid delay value$"
errmsg7 db "Program already installed$"
errmsg8 db "Invalid intensity value$"
initialize proc near
assume cs:code,ds:code
;
;See if a copy of DIMMER is already resident in memory.
;
cld ;Clear direction flag
mov word ptr [main],0 ;Initialize fingerprint
xor bx,bx ;Zero BX for start
mov ax,cs ;Keep CS value in AX
find_copy:
inc bx ;Increment search segment
mov es,bx
cmp ax,bx ;Not installed if current
je find_copy1 ; segment is found
mov si,offset main ;Search this segment for ASCII
mov di,si ; fingerprint.
mov cx,16
repe cmpsb
jne find_copy ;Loop back if not found
inc alrdy_installed ;Set installed flag
find_copy1:
mov other_seg,es ;Save segment value
;
;Verify that a VGA is installed.
;
mov ax,1A00h ;BIOS read display function
int 10h
mov dx,offset errmsg4
cmp al,1Ah ;See if VGA present
jne disp_error ;Exit on error if no VGA
;
;Parse the command line for switches.
;
mov si,offset command_tail+1 ;Point SI to command
parse_line_loop: ; tail in PSP
lodsb ;Scan command line for / or a
cmp al,32 ; number. Continue scanning
je parse_line_loop ; until a carriage return is
cmp al,13 ; found.
je parse_line_end
cmp al,"/" ;Is this a / character?
jne check_numeric ;No, then check for numeric
lodsb ;Get next character
or al,20h ;Convert to lower case
cmp al,"u" ;Check for uninstall switch
je uninstall_found
cmp al,"d" ;Check for delay switch
je delay_found
cmp al,"v" ;Check for reset delay by
je vidflag_found ; video call switch.
parse_line_error:
mov dx,offset errmsg2 ;Syntax error
jmp short disp_error ;Display message and exit
;
;Read the dimmer value from the command line if entry is numeric.
;
check_numeric:
cmp al,"-" ;Convert ASCII number into
je numeric_start ; binary. Check for leading
cmp al,"+" ; sign.
je numeric_start
cmp al,"0"
jb parse_line_error
cmp al,"9"
ja parse_line_error
dec si
numeric_start:
or change_flag,1 ;Set bit 0 in change flag
call setdim ;Read and set dimmer value
jmp short chk_err_and_loop ;Check for error return
;
;Read the time delay and dimmer values from the command line.
;
vidflag_found:
call setvidflag ;Modify the state of video flg
jmp short chk_err_and_loop ;Check for error return
delay_found:
or change_flag,2 ;Set bit 1 in change flag
call setdelay ;Read and set delay value
chk_err_and_loop:
jc disp_error
jmp short parse_line_loop
;
;Uninstall the program from memory.
;
uninstall_found:
mov dx,offset errmsg1 ;Make sure program is
cmp alrdy_installed,0 ; installed and signal
je disp_error ; error if it is not
call remove ;Remove program from memory
mov dx,offset errmsg3
jc disp_error ;Error if can't remove
mov dx,offset infomsg1 ;Acknowledge if removed
call print_string
exit:
mov ax,4C00h ;Exit with RC = 0
int 21h
;
;Process new dimmer and/or delay values now if DIMMER is already resident.
;
parse_line_end:
cmp alrdy_installed,0 ;Program already installed?
je install ;No, then install it
cmp change_flag,0 ;Changes to resident copy?
jne check_dimmer_change ;Yes, then process them
mov dx,offset errmsg7
disp_error:
call print_string ;No, then display error
mov ax,4C01h ; message and exit
int 21h ; with RC = 1
check_dimmer_change:
test change_flag,1 ;Adjust color registers if
jz check_delay_change ; dimmer value was changed
push ds
mov ds,other_seg ;Point DS to installed
assume ds:nothing ; segment
mov ah,ds:[dimmer_val]
call adj_palette_1
pop ds
assume ds:code
jmp exit ;Terminate
check_delay_change:
test change_flag,2 ;Exit now if delay value
jnz exit ; was modified
;
;Install a copy of DIMMER.
;
install:
mov ax,3508h ;Hook into interrupt 8
int 21h
mov word ptr int08h,bx
mov word ptr int08h[2],es
mov ax,2508h
mov dx,offset timerint
int 21h
mov ax,3509h ;Hook into interrupt 9
int 21h
mov word ptr int09h,bx
mov word ptr int09h[2],es
mov ax,2509h
mov dx,offset kbint
int 21h
mov ax,3510h ;Hook into interrupt 10h
int 21h
mov word ptr int10h,bx
mov word ptr int10h[2],es
mov ax,2510h
mov dx,offset videoint
int 21h
mov dx,offset program ;Display copyright notice
call print_string ; and jump to final
jmp final_install ; install code
initialize endp
;-----------------------------------------------------------------------------
; PRINT_STRING displays a DOS "$"-delimited text string with leading and
; trailing CRLFs.
; Entry: DS:DX - String address
;-----------------------------------------------------------------------------
crlf db 13,10,"$"
print_string proc near
push dx ;Save entry-level value of DX
mov ah,9 ;Print leading CRLF
mov dx,offset crlf
int 21h
mov ah,9 ;Print text string
pop dx
int 21h
mov ah,9 ;Print trailing CRLF
mov dx,offset crlf
int 21h
ret ;Exit to caller
print_string endp
;-----------------------------------------------------------------------------
; SETVIDFLAG modifies the video reset flag.
; Entry: DS:SI - Address of optional sign value.
;-----------------------------------------------------------------------------
setvidflag proc near
mov al,1 ;Assume video flag enable
cmp byte ptr [si],"-" ;Check for video flag disable
jne setvidflag_1
dec al
setvidflag_1:
mov es,other_seg ;Point ES to installed seg
mov es:[restorebyvid],al ;Set/Reset video flag
clc
ret
setvidflag endp
;-----------------------------------------------------------------------------
; SETDIM sets the dimmer value.
; Entry: DS:SI - Address of first digit
; Exit: CF set on error (DX points to error message text)
;-----------------------------------------------------------------------------
setdim proc near
mov di,si ;Copy command line pointer
call asc2bin ;Convert ASCII to binary
mov dx,offset errmsg8 ;Exit on error
jc setdim_error
cmp byte ptr [di-1],"-" ;Negate value if negative
jne setdim_1
neg ax
setdim_1:
mov dx,offset errmsg5
cmp ax,63 ;Error if value is less than
jg setdim_error ; -63 or greater than +63
cmp ax,-63
jl setdim_error
mov es,other_seg ;Point ES to installed seg
mov es:[dimmer_val],al ;Record dimmer value
clc
setdim_exit:
ret
setdim_error:
stc
jmp short setdim_exit
setdim endp
;-----------------------------------------------------------------------------
; SETDELAY sets the delay counter.
; Entry: DS:SI - Address of first character past /D switch
; Exit: CF set on error (DX points to error message text)
;-----------------------------------------------------------------------------
setdelay proc near
setdelay_l1:
lodsb
cmp al,32 ;Skip spaces
je setdelay_l1
mov dx,offset errmsg2 ;Error if no delay value
cmp al,13 ; was specified
je setdelay_error
dec si ;Back up to first character
call asc2bin ;Convert ASCII to binary
mov dx,offset errmsg6 ;Exit on error
jc setdelay_error
mov bx,0FFFFh ;If delay value 0, disable
or ax,ax ; delay counter with FFFFh
je delay_2
mov bx,ax ;Save delay value
setdelay_l2:
lodsb ;Get next character
cmp al,32 ;Skip spaces
je setdelay_l2
mov dx,offset errmsg2 ;Error if no delay value
cmp al,13 ; was specified
je setdelay_error
mov di,si ;Copy pointer to number
cmp al,"-" ;Check for leading sign
je setdelay_1 ; identifier
cmp al,"+"
je setdelay_1
dec si ;Back up to first character
setdelay_1:
push bx ;Save delay value
call asc2bin ;ASCII --> binary
pop bx ;Retrieve delay value
mov dx,offset errmsg8 ;Exit on error
jc setdelay_error
cmp byte ptr [di-1],"-" ;Negate value if negative
jne delay_1
neg ax
delay_1:
mov dx,offset errmsg5 ;Check to see if the value
cmp ax,63 ; is out of range
jg setdelay_error
cmp ax,-63
jl setdelay_error
delay_2:
mov es,other_seg ;Load new delay and dimmer
mov es:[delaydimval],al ; values into the
mov es:[wait_time],bx ; program
mov es:[dim_counter],bx
mov es:[second_cnt],1092
clc
setdelay_exit:
ret
setdelay_error:
stc
jmp short setdelay_exit
setdelay endp
;-----------------------------------------------------------------------------
; REMOVE removes a resident copy of the program from memory.
; Exit: CF set on error
;-----------------------------------------------------------------------------
remove proc near
cmp alrdy_installed,0 ;See if installed
je remove_error ;No, error
mov ax,3508h ;Get timer vector
int 21h
mov ax,es ;Check to make sure timer
cmp ax,other_seg ; vector not modified
jne remove_error
mov ax,3509h ;Get keyboard vector
int 21h
mov ax,es ;Check to make sure keyboard
cmp ax,other_seg ; vector not modified
jne remove_error
mov ax,3510h ;Get video vector
int 21h
mov ax,es ;Check to make sure video
cmp ax,other_seg ; vector not modified
jne remove_error
push ds
lds dx,es:[int08h] ;Get old interrupt 8 vector
mov ax,2508h ;Set interrupt
int 21h
lds dx,es:[int09h] ;Get old interrupt 9 vector
mov ax,2509h ;Set interrupt
int 21h
lds dx,es:[int10h] ;Get old interrupt 10 vector
mov ax,2510h ;Set interrupt
int 21h
pop ds
mov cx,es:[env_segment]
mov ah,49h ;Free PSP block
int 21h
mov es,cx ;Free environment block
mov ah,49h
int 21h
remove_exit:
clc
remove_exit1:
ret
remove_error:
stc
jmp remove_exit1
remove endp
;-----------------------------------------------------------------------------
; ASC2BIN Converts an ASCII number pointed to by SI to a hex value.
; Entry: SI = pointer to ASCII number
; Exit: AX = binary value
; CF set on error
;-----------------------------------------------------------------------------
ten dw 10
asc2bin proc near
xor ax,ax ;Clear accumulator
xor bx,bx ;Clear BX
asc_loop:
mov bl,[si] ;Get ASCII character
cmp bl,13 ;Done if carriage return or
je asc_exit ; space encountered
cmp bl,32
je asc_exit
inc si
sub bl,"0" ;ASCII --> binary
jb asc_error ;Error if binary value is
cmp bl,9 ; less than 0 or greater
ja asc_error ; than 9
mul ten ;Multiply accumulator by 10
add ax,bx ;Add last digit to sum
jmp short asc_loop ;Loop until done
asc_exit:
clc
asc_exit1:
ret
asc_error:
stc
jmp short asc_exit1
asc2bin endp
code ends
end main
