flat assembler

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pool

Joined: 08 Jan 2007
Posts: 97

pool 11 Jan 2008, 05:22

Last edited by pool on 17 Mar 2013, 11:42; edited 1 time in total

11 Jan 2008, 05:22

LocoDelAssembly
Your code has a bug

Joined: 06 May 2005
Posts: 4624
Location: Argentina

LocoDelAssembly 11 Jan 2008, 06:25

masking as masking bits or what?

11 Jan 2008, 06:25

shoorick

Joined: 25 Feb 2005
Posts: 1614
Location: Ukraine

shoorick 11 Jan 2008, 09:55

interrupts?

11 Jan 2008, 09:55

edfed

Joined: 20 Feb 2006
Posts: 4335
Location: Now

edfed 11 Jan 2008, 11:32

the mask? with jim carrey?

11 Jan 2008, 11:32

pool

Joined: 08 Jan 2007
Posts: 97

pool 17 Jan 2008, 10:53

Last edited by pool on 17 Mar 2013, 11:42; edited 1 time in total

17 Jan 2008, 10:53

dosin

Joined: 24 Aug 2007
Posts: 337

dosin 17 Jan 2008, 18:30

http://neworder.box.sk/news/6876

This site may help..

Code:

remap_pic:          
        mov al, 0x11           ;; INIT command
        out 0x20, al           ;; Send the INIT command to PIC1
        call io_delay          ;; Delays after IO reads
        out 0xA0, al           ;; Send the INIT command to PIC2
        call io_delay
        mov al, 0x20           ;; The start of the PIC1 interrupts
        out 0x21, al           ;; Send the port to PIC1 DATA
        call io_delay
        mov al, 0x28           ;; The start of the PIC2 interrupts
        out 0xA1, al           ;; Send the port to PIC2 DATA
        call io_delay
        mov al, 0x04           ;; Set the code for MASTER
        out 0x21, al           ;; Set PIC1 as master
        call io_delay
        mov al, 0x02           ;; Set the code for SLAVE
        out 0xA1, al
        call io_delay
        mov al, 0x01           ;; 8086 mode code
        out 0x21, al
        call io_delay
        out 0xA1, al
        call io_delay
        mov al, 0xFB           ;; This masks off all IRQs except the cascaded
        out 0x21, al
        call io_delay
        mov al, 0xFF           ;; Masks off all IRQs on PIC2
        out 0xA1, al
        call io_delay
        ret
io_delay:
        jmp $+2
        ret

This is from that site - follow the link and it will give you a better description of what is going on in the above code..

17 Jan 2008, 18:30

edfed

Joined: 20 Feb 2006
Posts: 4335
Location: Now

edfed 18 Jan 2008, 00:56

Code:

...
          mov esi,picmap1
          call picmap
...
picmap1:
db 20h,28h
db 0fbh,0ffh
...
picmap:
;esi = params
;params:
.pic1base=0
.pic2base=1
.pic1msk=2
.pic2msk=3
        mov al, 0x11           ;; INIT command 
        out 0x20, al           ;; Send the INIT command to PIC1 
        call .delay          ;; Delays after IO reads 
        out 0xA0, al               ;; Send the INIT command to PIC2 
        call .delay 
        mov al,[esi+pic1base] 
        out 0x21, al               ;; Send the port to PIC1 DATA 
        call .delay 
        mov al,[esi+.pic2base] 
        out 0xA1, al           ;; Send the port to PIC2 DATA 
        call .delay 
        mov al, 0x04           ;; Set the code for MASTER 
        out 0x21, al           ;; Set PIC1 as master 
        call .delay 
        mov al, 0x02           ;; Set the code for SLAVE 
        out 0xA1, al 
        call .delay 
        mov al, 0x01           ;; 8086 mode code 
        out 0x21, al 
        call .delay 
        out 0xA1, al 
        call .delay 
        mov al,[esi+.pic1msk]
        out 0x21, al 
        call .delay 
        mov al,[esi+.pic2msk]  
        out 0xA1, al 
        call .delay 
        ret 
.delay: 
        jmp $+2 
        ret

like it, this code become modular. and easy to configure.

18 Jan 2008, 00:56

zhak

Joined: 12 Apr 2005
Posts: 501
Location: Belarus

zhak 18 Jan 2008, 20:54

it's written that a software delay must be implemented when accessing i/o ports in the artictle at http://neworder.box.sk/news/6876. but i've read that this delay is not needed on modern PCs. so should there be any delays or not? my question corresponds to any i/o ports (keyboard, rtc, ide... etc) not only PIC ports.

18 Jan 2008, 20:54

edfed

Joined: 20 Feb 2006
Posts: 4335
Location: Now

edfed 18 Jan 2008, 21:27

delayed version need to be used, because of compativility for older PCs.
but, in some years, it will be endless.
the delay can be ignored cause of instructions beetwen two IO instructions.

18 Jan 2008, 21:27

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