.386 
.model flat,stdcall 
option casemap:none 
	include Windows.inc 
	include user32.inc 
	includelib user32.lib            
	include kernel32.inc 
	includelib kernel32.lib
IDD_DIALOG1       EQU           101
IDC_RADIO1        EQU           1000
IDC_RADIO2        EQU           1001
IDC_RADIO3        EQU           1002
IDC_RADIO4        EQU           1003
ID_START          EQU           1004
ID_EXIT           EQU           1005 

.data
CLK dw 31250
IOport dw 0A400h
w8253 dw 20h

.data?
rNum dw ?

.code

DlgProc proc hDlg, uMsg, wParam, lParam

.if uMsg == WM_INITDIALOG 
	invoke GetDlgItem,hDlg,ID_START
	invoke EnableWindow,eax,FALSE  
	invoke GetDlgItem,hDlg,ID_EXIT
	invoke EnableWindow,eax,FALSE
	
.elseif uMsg == WM_COMMAND
	mov eax, wParam
	.if ax == IDC_RADIO1
		mov ax, CLK 
		shl ax, 1
		mov rNum, ax
		invoke GetDlgItem,hDlg,ID_START
		invoke EnableWindow,eax,TRUE
		invoke GetDlgItem,hDlg,ID_EXIT
		invoke EnableWindow,eax,TRUE		
	.elseif ax == IDC_RADIO2
		mov ax, CLK
		mov rNum, ax	
		invoke GetDlgItem,hDlg,ID_START
		invoke EnableWindow,eax,TRUE
		invoke GetDlgItem,hDlg,ID_EXIT
		invoke EnableWindow,eax,TRUE	
	.elseif ax == IDC_RADIO3
		mov ax, CLK
		shr ax, 1
		mov rNum, ax
		invoke GetDlgItem,hDlg,ID_START
		invoke EnableWindow,eax,TRUE
		invoke GetDlgItem,hDlg,ID_EXIT
		invoke EnableWindow,eax,TRUE
	.elseif ax == IDC_RADIO4
		mov ax, CLK
		mov dx, 0
		mov bx, 5
		div bx
		mov rNum, ax
		invoke GetDlgItem,hDlg,ID_START
		invoke EnableWindow,eax,TRUE
		invoke GetDlgItem,hDlg,ID_EXIT
		invoke EnableWindow,eax,TRUE

	.elseif ax == ID_START
		mov al, 00110110b
		mov dx, IOport
		add dx, w8253
		add dx, 3
		out dx, al
		mov dx, IOport
		add dx, w8253
		mov ax, rNum
		out dx, al
		mov al, ah
		out dx, al

	.elseif ax == ID_EXIT
		invoke EndDialog,hDlg,NULL
	.endif	
			
  
.elseif	uMsg ==	WM_CLOSE	
	invoke EndDialog,hDlg,NULL
.else
	mov eax,FALSE
	ret
.endif
mov eax,TRUE
ret

DlgProc endp
		
START:
invoke GetModuleHandle, NULL
invoke DialogBoxParam, eax, IDD_DIALOG1, NULL, DlgProc, NULL
invoke ExitProcess,NULL
END START