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HAM Radio 3
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hamradioversion3.0examsandprograms1992.iso
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9q920411
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pivec.asm
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Assembly Source File
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1992-04-03
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3KB
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198 lines
; :ts=8
.MODEL MEMMOD,C
LOCALS
%MACS
.LALL
extrn Stktop,Spsave,Sssave,piint:proc,doret:proc,eoi:proc
DMAEN equ 4
.DATA
public acc_delay
acc_delay dw 0
.CODE
dbase dw @Data ; save loc for ds (must be in code segment)
public mloop
mloop proc
mov cx,65535
Loop7:
nop
loop Loop7
ret
mloop endp
public wrtscc
wrtscc proc
arg cbase:word,ctl:word,reg:word,val:word
pushf
cli
mov dx,cbase ; get address of dma enable port
add dx,DMAEN
mov al,0 ; Write a 0 to disable DMA while we touch the scc
out dx,al
mov cx,acc_delay
Loop1: nop
loop Loop1
mov dx,ctl ; Get address of scc control reg
mov ax,reg ; Select register
out dx,al
mov cx,acc_delay
Loop2: nop
loop Loop2
mov ax,val ; Output value
out dx,al
mov cx,acc_delay
Loop3: nop
loop Loop3
mov dx,cbase ; get address of dma enable port
add dx,DMAEN
mov al,1 ; Enable DMA
out dx,al
popf
ret
wrtscc endp
public rdscc
rdscc proc
arg cbase:word,ctl:word,reg:byte
pushf
cli
mov dx,cbase ; Get address of dma enable port
add dx,DMAEN;
mov al,0 ; Disable DMA while we touch the scc
out dx,al;
mov cx,acc_delay
Loop4: nop
loop Loop4
mov dx,ctl ; Get address of SCC control reg
mov al,reg ; Select register
out dx,al;
mov cx,acc_delay
Loop5: nop
loop Loop5
in al,dx ; read register
xor ah,ah
push ax ; save return value
mov cx,acc_delay
Loop6: nop
loop Loop6
mov dx,cbase ; get address of dma enable port
add dx,DMAEN
mov al,1 ; Enable DMA
out dx,al
pop ax ; recover return value
popf
ret
rdscc endp
; pi0vec - Pi card #0 interrupt handler
public pi0vec
label pi0vec far
push ds ; save on user stack
mov ds,cs:dbase ; establish interrupt data segment
mov Sssave,ss ; stash user stack context
mov Spsave,sp
mov ss,cs:dbase
lea sp,Stktop
push ax ; save user regs on interrupt stack
push bx
push cx
push dx
push bp
push si
push di
push es
call eoi
mov ax,0 ; arg for service routine
push ax
call piint
inc sp
inc sp
jmp doret
; pi1vec - Pi card #1 interrupt handler
public pi1vec
label pi1vec far
push ds ; save on user stack
mov ds,cs:dbase ; establish interrupt data segment
mov Sssave,ss ; stash user stack context
mov Spsave,sp
mov ss,cs:dbase
lea sp,Stktop
push ax ; save user regs on interrupt stack
push bx
push cx
push dx
push bp
push si
push di
push es
call eoi
mov ax,1 ; arg for service routine
push ax
call piint
inc sp
inc sp
jmp doret
; pi2vec - Pi card #2 interrupt handler
public pi2vec
label pi2vec far
push ds ; save on user stack
mov ds,cs:dbase ; establish interrupt data segment
mov Sssave,ss ; stash user stack context
mov Spsave,sp
mov ss,cs:dbase
lea sp,Stktop
push ax ; save user regs on interrupt stack
push bx
push cx
push dx
push bp
push si
push di
push es
call eoi
mov ax,2 ; arg for service routine
push ax
call piint
inc sp
inc sp
jmp doret
end