|
|
kbd equ 16h ;keyboard irq
|
|
|
msdos equ 21h ;MSDOS irq
|
|
|
|
|
|
reset equ 0dh ;disk reset
|
|
|
dfopen equ 0fh ;open disk file
|
|
|
dfclose equ 10h ;close disk file
|
|
|
searchf equ 11h ;search first
|
|
|
searchn equ 12h ;search next
|
|
|
seqread equ 14h ;sequential disk read
|
|
|
seqwrite equ 15h ; " " write
|
|
|
setdta equ 1ah ;set disk transfer area address
|
|
|
createf equ 3ch ;create file with handle
|
|
|
openf equ 3dh ;open file with handle
|
|
|
closef equ 3eh ;close file with handle
|
|
|
readf equ 3fh ;read from file with handle
|
|
|
writef equ 40h ;write to file with handle
|
|
|
setfp equ 42h ;set file pointer
|
|
|
allocmem equ 48h ;allocate memory
|
|
|
freemem equ 49h ;free memory
|
|
|
changebs equ 4ah ;change block size
|
|
|
findfirst equ 4eh ;find first file
|
|
|
exit equ 4c00h ;msdos exit
|
|
|
|
|
|
[BITS 16] ;NASM stuff
|
|
|
[ORG 0x100]
|
|
|
|
|
|
s1:
|
|
|
mov ax,cs ;get code segment
|
|
|
mov ds,ax ;use it now
|
|
|
mov [comseg],ds ;save it there
|
|
|
|
|
|
mov si,0080h ;DOS command line page 0
|
|
|
lodsb ;load size of command line
|
|
|
cmp al,0 ;anything on command line ?
|
|
|
jbe usage ;noo, show usage
|
|
|
cbw ;extend AL to AX
|
|
|
xchg bx,ax ;swap size to bx for indexing
|
|
|
mov byte [bx+si],0 ;null terminate command line
|
|
|
call parse ;parse command line
|
|
|
jmp main ;go on with main
|
|
|
usage: mov bx,utext ;pointer usage text
|
|
|
jmp errout ;skip this
|
|
|
main:
|
|
|
mov si,inbuff ;check for valid HEX input
|
|
|
mov bx,errt1 ;proper text
|
|
|
ishex: lodsb ;get the char
|
|
|
cmp al,'0'
|
|
|
jb errout
|
|
|
and al,0dfh ;force UPPERCASE
|
|
|
cmp al,'F' ;>F ?
|
|
|
ja errout ;yeahh, dump this
|
|
|
loop ishex
|
|
|
call hexbin ;make hex bin
|
|
|
;start address now in EDX
|
|
|
mov ax,dx ;get low word (segment)
|
|
|
mov es,ax ;start segment
|
|
|
shr edx,16 ;shift in offset
|
|
|
mov di,dx ;start offset
|
|
|
dopage:
|
|
|
push es ;save registers
|
|
|
push di
|
|
|
push ds
|
|
|
push si
|
|
|
mov ax,es
|
|
|
mov ds,ax ;make ds=es
|
|
|
mov si,di ;and si=di
|
|
|
|
|
|
call showpage ;show it
|
|
|
|
|
|
pop si ;restore registers
|
|
|
pop ds
|
|
|
pop di
|
|
|
pop es
|
|
|
add di,512 ;adjust memory position
|
|
|
|
|
|
;xor ah,ah ;wait for ANY key
|
|
|
;int kbd
|
|
|
|
|
|
mov bx,text ;show message
|
|
|
call write
|
|
|
mov ah,0 ;wanna see next screen ?
|
|
|
int kbd ;chek out keyboard buffer
|
|
|
and al,0DFh ;force UPPER CASE
|
|
|
cmp al,"Q" ;wanna quit ?
|
|
|
je quit ;yeahh
|
|
|
jmp dopage
|
|
|
errout:
|
|
|
call write
|
|
|
quit:
|
|
|
mov ax,exit
|
|
|
int msdos
|
|
|
|
|
|
;***********************************************************
|
|
|
;* Convert ascii hex to 32 bit binary
|
|
|
;* Input = command line buffer, output EDX
|
|
|
;***********************************************************
|
|
|
hexbin:
|
|
|
mov si,inbuff ;pointer command line buffer
|
|
|
xor edx,edx ;clear binary output
|
|
|
aschexbin:
|
|
|
lodsb
|
|
|
cmp al,'0' ;< 0
|
|
|
jb notasc ;yes invalid character
|
|
|
cmp al,'9' ;<= 9
|
|
|
jbe astrip ;yes, strip high 4 bits
|
|
|
and al,05fh ;force upper case
|
|
|
cmp al,'A' ;< ascii A
|
|
|
jb notasc ;yes, invalid character
|
|
|
cmp al,'F' ;> ascii F
|
|
|
ja notasc ;yes, invalid character
|
|
|
add al,9 ;ok, add 9 for strip
|
|
|
astrip:
|
|
|
and al,0fh ;strip high 4 bits
|
|
|
mov cx,4 ;set shift count
|
|
|
shl edx,cl ;rotate EDX 4 bits
|
|
|
xor ah,ah ;zero out AH
|
|
|
cbw
|
|
|
add edx,eax ;add digit to value
|
|
|
jmp aschexbin ;continue
|
|
|
notasc: ret
|
|
|
|
|
|
;*********************************************************************
|
|
|
;* Format and show the stuff in a "sector"
|
|
|
;* Input SI
|
|
|
;*********************************************************************
|
|
|
showpage:
|
|
|
mov cx,32 ;32*16=512
|
|
|
arow: push cx
|
|
|
mov di,outline ;output buffer
|
|
|
mov cx,16 ;process 16 bytes
|
|
|
hexrow: push cx
|
|
|
lodsb ;load al with byte
|
|
|
mov dl,al ;get value
|
|
|
mov cx,2 ;2 nibbles
|
|
|
chexb: push cx ;save that
|
|
|
mov cl,4 ;4 bits
|
|
|
rol dl,cl ;rotate source left
|
|
|
mov al,dl ;move digit into AL
|
|
|
and al,15 ;clear high nibble
|
|
|
daa ;adjust AL if A through F
|
|
|
add al,240 ;bump the carry
|
|
|
adc al,40h ;convert HEX to ASCII
|
|
|
stosb ;copy to buffer
|
|
|
pop cx ;get digit counter
|
|
|
loop chexb ;next digit
|
|
|
mov al,32 ;copy a SPACE
|
|
|
stosb
|
|
|
pop cx ;restore loop counter
|
|
|
loop hexrow ;loop on
|
|
|
mov al,32 ;copy 2 spaces
|
|
|
stosb
|
|
|
stosb
|
|
|
sub si,16 ;adjust source back
|
|
|
mov cx,16 ;copy ASCII bytes
|
|
|
cccp: lodsb
|
|
|
cmp al,32 ;< SPACE ?
|
|
|
jb noa ;yeahh, skip it
|
|
|
stosb ;no, store in buffer
|
|
|
jmp next
|
|
|
noa: mov al,'.'
|
|
|
stosb
|
|
|
next loop cccp
|
|
|
mov al,13
|
|
|
stosb
|
|
|
mov al,10
|
|
|
stosb
|
|
|
mov al,0 ;null terminate line
|
|
|
stosb
|
|
|
mov bx,outline ;show the line
|
|
|
call write
|
|
|
pop cx
|
|
|
cmp cx,17
|
|
|
jne nopause
|
|
|
push ds
|
|
|
mov ax,cs
|
|
|
mov ds,ax
|
|
|
mov bx,text1
|
|
|
call write
|
|
|
pop ds
|
|
|
xor ah,ah
|
|
|
int kbd
|
|
|
nopause:
|
|
|
loop arow ;next 16 bytes
|
|
|
ret
|
|
|
|
|
|
;************************************************************************'
|
|
|
;* Convert bin WORD to HEX ascii. Input DX. Result in Numbuff *
|
|
|
;************************************************************************
|
|
|
binhex: pusha
|
|
|
mov di,numbuff ;destination buffer
|
|
|
mov dx,[count] ;binary number
|
|
|
mov cx,4 ;four nibbles
|
|
|
convhex:
|
|
|
push cx ;save counter
|
|
|
mov cl, 4 ;4 bits
|
|
|
rol dx, cl ;rotate source left
|
|
|
mov al, dl ;move digit into AL
|
|
|
and al, 15 ;clear high nibble
|
|
|
daa ;adjust AL if A through F
|
|
|
add al, 240 ;bump the carry
|
|
|
adc al, 40h ;convert HEX to ASCII
|
|
|
stosb ;copy to buffer
|
|
|
pop cx ;get digit counter
|
|
|
loop convhex ;next digit
|
|
|
mov al,32 ;copy a space
|
|
|
stosb
|
|
|
mov al,0 ;null terminate
|
|
|
stosb
|
|
|
popa
|
|
|
ret
|
|
|
|
|
|
;*************************************************************************
|
|
|
;* Writes out the NULL terminated text supplied in BX. *
|
|
|
;* OR writes out data,BX and size,CX if called at lwrite. *
|
|
|
;*************************************************************************
|
|
|
write: pusha
|
|
|
mov si,bx ;copy to SI
|
|
|
mov cx,0 ;clear count
|
|
|
wloop: lodsb ;load AL with SI
|
|
|
cmp al,0 ;end of line ?
|
|
|
je lwrite ;yeahh
|
|
|
inc cx ;no, incrase byte count
|
|
|
jmp wloop ;test next byte
|
|
|
lwrite: mov dx,bx ;text address in DX
|
|
|
mov bx,1 ;filehandle standard output = 1
|
|
|
mov ah,writef ;MS-DOS writefile with handle is 040
|
|
|
int msdos ;write buffer to standard output
|
|
|
popa
|
|
|
ret ;done
|
|
|
|
|
|
;*************************************************************************
|
|
|
;* My kind of command line parsing. It just checks if there<72>s
|
|
|
;* any blankspaces between the options. The parameters ends up
|
|
|
;* in the inbuff separated by 0:s, binary zeroes.
|
|
|
;*************************************************************************
|
|
|
parse:
|
|
|
mov di,inbuff ;our buffer
|
|
|
ifspc: cmp byte [si],32 ;leading space ?
|
|
|
jne nospc ;noo
|
|
|
inc si ;yeahh, dump that
|
|
|
jmp ifspc ;check next
|
|
|
nospc: mov cx,1 ;were here, so we got one arg
|
|
|
copy1: lodsb ;load byte SI to AL
|
|
|
cmp al,0 ;0 ?(end of line)
|
|
|
je done ;yeahh
|
|
|
cmp al,32 ;SPACE ?
|
|
|
je cop2 ;yeah
|
|
|
stosb ;noo, move AL to DI, incrase DI
|
|
|
jmp copy1 ;go on
|
|
|
cop2: mov byte [di],0 ;null terminate
|
|
|
add cx,1
|
|
|
inc di ;dump that byte(SPACE)
|
|
|
jmp copy1 ;back
|
|
|
done: mov byte [di],0 ;null terminate
|
|
|
ret ;return
|
|
|
|
|
|
|
|
|
;*************************** DATA STUFF **********************************
|
|
|
|
|
|
XMS_SEGMENT dw 0
|
|
|
XMS_OFFSET dw 0
|
|
|
|
|
|
inbuff times 64 dw 0 ;128 byte command line buffer
|
|
|
outline times 40 dw 0 ;buffer output line
|
|
|
numbuff times 7 dw 0 ;word ascii number buffer
|
|
|
comseg dw 0
|
|
|
count dw 0
|
|
|
bcount dw 0
|
|
|
acount dw 0
|
|
|
|
|
|
;outbuff times 512 db 0
|
|
|
|
|
|
|
|
|
utext db 'WWW',13,10
|
|
|
db 'Usage: Showmem [start address].',13,10
|
|
|
db 'Start address = Hexadecimal.',13,10,0
|
|
|
text: db 13,10,'Q = Quit. Any key = Next page.',13,10,0
|
|
|
text1: db 13,10,'Any Key = Next 256 Bytes.',13,10,0
|
|
|
errt1: db 'That address is not hexadecimal.',13,10,0
|
|
|
|
|
|
s2:
|
|
|
|
|
|
END |