Ham Radio 2000 #1

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Assembly Source File | 1991-02-17 | 29.0 KB | 617 lines

;==========================================================================; ; 8250 Extended functions ; ; ; ; Copyright 1983 by William E. Westfield. All rights reserved. ; ; Copyright 1986, 1988, 1991 by H. Roy Engehausen. All rights reserved. ; ; This software may be freely distributed and used, but it may not ; ; under any circumstances be sold by anyone other than the author. ; ; It may be distributed by a commercial company as long as it is ; ; for no cost. ; ; ; ; AH = 4 Inquiry ; ; ------------------ ; ; AH returns 0AAH. AL returns 055H. This call is used to see if this ; ; driver has been loaded for a particular port. ; ; ; ; AH = 5 Drop RTS ; ; ------------------- ; ; This drops DTR (pin 20) and RTS (pin 4). Used to tell the TNC not to ; ; send any more information. TNC-1 and PK-232 use pin 4 for handshaking. ; ; TNC-2 uses pin 20 (dont ask me why!) No return value. ; ; ; ; AH = 6 Raise RTS ; ; -------------------- ; ; Raise DTR and RTS. No return value. ; ; ; ; AH = 7 Send Break ; ; --------------------- ; ; Generates a "Break". No return value. ; ; ; ; AH = 8 Non-destructive Read ; ; ------------------------------- ; ; Returns the next character in the buffer in AL without removing it from ; ; the buffer. AH value same as code 1. No check for character ready ; ; ; ; AH = 9 Set/Get options ; ; -------------------------- ; ; Set the current option byte to AL returning the old option byte in AL. ; ; ; ; AH = A Write buffer ; ; ----------------------- ; ; Sends CX characters starting at DI:ES ; ; ; ; AH = B Read buffer ; ; ---------------------- ; ; Receives up to CX characters starting at DI:ES. CX set to actual ; ; count read ; ; ; ; AH = C Send/Receive DED Hostmode buffer ; ; ------------------------------------------- ; ; Not implemented for 8250 ; ; ; ;==========================================================================; ;==========================================================================; ; Inquiry ; ;==========================================================================; rsint_8250_inquiry: MOV AX,0AA55H ; Set footprint JMP rsint_exit ; All done ;==========================================================================; ; Drop RTS/DTR handshaking ; ;==========================================================================; rsint_8250_droprts: MOV DX,baseaddr[SI] ; Get base address for chip ADD DX,mcr_8250 ; Select MCR MOV AL,hoff_8250 ; Turn off sending from distant end OUT DX,AL ; OR flags[SI],flags_useoff ; Signal user wants handshake off JMP rsint_exit ; All done ;==========================================================================; ; Turn on RTS/DTR handshaking ; ;==========================================================================; rsint_8250_raiserts: MOV DX,baseaddr[SI] ; Get base address for chip ADD DX,mcr_8250 ; MOV AL,hon_8250 ; Raise DTR, RTS, and OUT2. OUT2 turns OUT DX,AL ; on interrupts. AND flags[SI],0FFH-flags_useoff ; Turn off force handshake flag JMP rsint_exit ; All done ;==========================================================================; ; Break! ; ;==========================================================================; rsint_8250_sendbrk: ;--------------------------------------------------------------------------; ; First we see if we are going to use a hardware break or a ; ; simulated break using three control "C" ; ;--------------------------------------------------------------------------; TEST options[SI],opt_brktr ; Translate break to control "C" JNZ rsint_8250_sendbrk_tr ; Yep! ;--------------------------------------------------------------------------; ; Hardware break. Set the bit in the LCR (without disturbing the rest ; ; and then loop for a while ; ;--------------------------------------------------------------------------; PUSH ES ; We are going to use ES, so save it MOV AX,040H ; Point ES down to the BIOS region MOV ES,AX MOV DX,baseaddr[SI] ; Get base address for chip ADD DX,lcr_8250 ; Select LCR IN AL,DX ; Read LCR PUSH AX ; and save it OR AL,lcr_8250_sb ; Force on the SET BREAK bit OUT DX,AL ; and output the SET BREAK bit rsint_8250_sendbrk_too_big: MOV CX, WORD PTR ES:[006Ch] ; Get current time tick count MOV BX,CX ; Save it in bx ADD CX,4 ; Calc target end-of-loop tick count CMP CX, BX ; Will it roll over? JB rsint_8250_sendbrk_lp2 ; Yep... ; CX > BX. No rollover needed ; If tick is not between bx and cx, then exit loop rsint_8250_sendbrk_lp1: MOV AX,WORD PTR es:[006Ch] ; Get time tick CMP AX,CX ; Has tick past target? JA rsint_8250_sendbrk_done ; Yep, done CMP AX,BX ; Has tick rolled over? JB rsint_8250_sendbrk_done ; Yep, done JMP rsint_8250_sendbrk_lp1 ; Need to loop ; CX < BX -- We will roll over ; If tick is not outside BX and CX, then exit loop rsint_8250_sendbrk_lp2: MOV AX,WORD PTR es:[006Ch] ; Get time tick CMP AX,CX ; Has tick past target? JB rsint_8250_sendbrk_lp2 ; Nope, loop CMP AX,BX ; Has tick past target? JAE rsint_8250_sendbrk_lp2 ; Nope, loop ; Break is complete rsint_8250_sendbrk_done: POP AX ; Retrieve the lcr status OUT DX,AL ; and output it POP ES ; Retrieve ES JMP rsint_exit ; All done ;--------------------------------------------------------------------------; ; Translated break. Send three control-C in a row ; ;--------------------------------------------------------------------------; rsint_8250_sendbrk_tr: MOV BX,baseaddr[SI] ; Get base address for chip MOV CX,3 ; Three characters wanted MOV AH,03H ; Control-C ;--------------------------------------------------------------------------; ; Loop thru here 3 times ; ;--------------------------------------------------------------------------; rsint_8250_sendbrk_loop1: ; ;--------------------------------------------------------------------------; ; Loop waiting for TBE ; ;--------------------------------------------------------------------------; MOV DX,BX ; Compute port address for the LSR ADD DX,lsr_8250 ; rsint_8250_sendbrk_loop2: ; Loop here until we can send IN AL,DX ; Get the LSR into AX TEST AL,lsr_8250_thre ; THR empty? JZ rsint_8250_sendbrk_loop2 ; No.. Loop back ;--------------------------------------------------------------------------; ; Out the character ; ;--------------------------------------------------------------------------; MOV AL,AH ; Get ready to out character MOV DX,BX ; Compute port address for the THR ADD DX,thr_8250 ; and then OUT DX,AL ; out the character ;--------------------------------------------------------------------------; ; Loop through all three characters ; ;--------------------------------------------------------------------------; LOOP rsint_8250_sendbrk_loop1 ; If not done then loop back JMP rsint_exit ; All done ;==========================================================================; ; Non destructive read ; ;==========================================================================; rsint_8250_ndr: ;--------------------------------------------------------------------------; ; Get the current character in the buffer. Make no check for character ; ; ready ; ;--------------------------------------------------------------------------; MOV BX,buffer_r_out[SI] ; Get buffer output pointer MOV ES,buffer_r_a[SI] ; Get buffer segment MOV AL,ES:[BX] ; Get character from buffer.. ;--------------------------------------------------------------------------; ; Set the status byte. ; ;--------------------------------------------------------------------------; MOV AH,last_rs[SI] ; Get last LSR from receive AND AH,0FFH-lsr_8250_dr ; Remove data ready bit CMP BX,buffer_r_in[SI] ; Anything left in buffer? JE rsint_8250_ndr_go ; Nope so leave OR AH,lsr_8250_dr ; Turn on data ready rsint_8250_ndr_go: ; JMP rsint_exit ; All done ;==========================================================================; ; Set option byte ; ;==========================================================================; rsint_8250_sopt: ; XCHG AL,options[SI] ; JMP rsint_exit ; All done ;==========================================================================; ; Block write ; ;==========================================================================; rsint_8250_buffw: ; TEST options[SI],opt_trbuf ; Transmit buffering turned on? JNZ rsint_8250_bufw_bw ; Yes.. go there now! ;--------------------------------------------------------------------------; ; Unbuffered block write ; ;--------------------------------------------------------------------------; ;--------------------------------------------------------------------------; ; Get the user's parameters and initialize ; ;--------------------------------------------------------------------------; MOV BX,SP ; Need access to stack MOV DI,SS:stack_di[BX] ; Get the offset MOV ES,SS:stack_es[BX] ; Get the displacement MOV BX,SS:stack_cx[BX] ; Get the size to send MOV CX,baseaddr[SI] ; Get base address for chip ;--------------------------------------------------------------------------; ; Loop sending ; ;--------------------------------------------------------------------------; rsint_8250_bufw_ubw: MOV AH,ES:[DI] ; Get character to send CALL rsint_8250_send_unb ; Send it INC DI ; Bump pointer DEC BX ; -1 from count JNZ rsint_8250_bufw_ubw ; Loop back ;--------------------------------------------------------------------------; ; Store results and exit ; ;--------------------------------------------------------------------------; SUB AX,AX ; Need a zero MOV BX,SP ; Need access to stack MOV SS:stack_di[BX],DI ; Set the offset MOV SS:stack_cx[BX],AX ; Set the count remaining(0) JMP rsint_8250_status ; Do a status ;--------------------------------------------------------------------------; ; Buffered block write ; ;--------------------------------------------------------------------------; rsint_8250_bufw_bw: ; ;--------------------------------------------------------------------------; ; Get the user's parameters and initialize ; ;--------------------------------------------------------------------------; MOV BX,SP ; Need access to stack MOV DX,SS:stack_cx[BX] ; Get the size to move MOV DI,buffer_t_in[SI] ; Get buffer input pointer AND flags[SI],0FFH-flags_was_e ; Turn off buffer empty flag OR DX,DX ; Anything to send? JNZ rsint_8250_bufw_loop; Yep CALL rsint_8250_bufw_int ; Cause a hardware interrupt JMP rsint_8250_bufw_end ; Nope ;--------------------------------------------------------------------------; ; This is the loop to move data to the buffer ; ; DI = input buffer position. ; ; DX = count left to move ; ;--------------------------------------------------------------------------; rsint_8250_bufw_loop: ; Move to buffer loop ;--------------------------------------------------------------------------; ; See if the buffer has gone empty and remember that. If it has then ; ; we will need to kick the interrupt servicer ; ;--------------------------------------------------------------------------; MOV AX,buffer_t_out[SI] ; See where the out pointer is ; CMP AX,DI ; Are they the same (empty buffer) ; JNE rsint_8250_bufw_ne ; No.... Buffer has something in it ; OR flags[SI],flags_was_e ; Yes... Turn on buffer empty flag rsint_8250_bufw_ne: ;--------------------------------------------------------------------------; ; Now get the space left in the buffer. ; ;--------------------------------------------------------------------------; CMP AX,DI ; Is the buffer wrapped? JG rsint_8250_bufw_nw ; Not wrapped MOV CX,AX ; Save AX MOV AX,buffer_size+1 ; Locate buffer_end + 1 for now JCXZ rsint_8250_bufw_nw ; Was AX zero? DEC AX ; rsint_8250_bufw_nw: SUB AX,DI ; AX = space left in buffer JNZ rsint_8250_bufw_ok ; Space is left! JMP rsint_8250_bufw_end ; No space left.. Its over rsint_8250_bufw_ok: ;--------------------------------------------------------------------------; ; Now calculate the size to move in this iteration. ; ; It will be the smallest of: ; ; 1) Buffer space (now in AX) ; ; 2) Data size (now in DX) ; ;--------------------------------------------------------------------------; CMP AX,DX ; JLE rsint_8250_bufw_m1 ; MOV AX,DX ; rsint_8250_bufw_m1: ; ; CMP AX,31 ; 63 bytes per move ; JLE rsint_8250_bufw_m2 ; ; MOV AX,31 ; Move only 63 rsint_8250_bufw_m2: ; ;--------------------------------------------------------------------------; ; Update the counters ; ;--------------------------------------------------------------------------; SUB DX,AX ; Drop the count to be moved by this move. ;--------------------------------------------------------------------------; ; Prep all the registers and do the move ; ;--------------------------------------------------------------------------; ASSUME DS:NOTHING; MOV CX,AX ; Get count MOV AX,SI ; Save SI MOV ES,buffer_t_a[SI] ; Get buffer segment MOV DS,SS:stack_es[BX] ; Get input segment MOV SI,SS:stack_di[BX] ; Get input offset ; CLI CLD ; The counter should go up! REP MOVSB ; Do the move MOV SS:stack_di[BX],SI ; Put back updated offset. MOV SI,AX ; Restore SI MOV CX,CS ; Restore DS MOV DS,CX ; ; STI ASSUME DS: everything ; ;--------------------------------------------------------------------------; ; Update the counters ; ;--------------------------------------------------------------------------; CMP DI,buffer_size ; Wrap the input pointer around the JL rsint_8250_bufw_now ; buffer if necessary SUB DI,DI ; rsint_8250_bufw_now: ; ;--------------------------------------------------------------------------; ; See if the buffer is empty disregarding what we just put int it. ; ; we will need to kick the interrupt servicer ; ;--------------------------------------------------------------------------; MOV AX,buffer_t_in[SI] ; See where the "old" input pointer is MOV buffer_t_in[SI],DI ; Save "new" input pointer CMP AX,buffer_t_out[SI] ; See where the out pointer is JNE rsint_8250_bufw_noi ; Not the same. Buffer still ok ; TEST flags[SI],flags_was_e ; Was it empty ; JZ rsint_8250_bufw_noi ; Not the same. Buffer still ok ;--------------------------------------------------------------------------; ; If buffer was empty, cause a false hardware interrupt by setting the IIR ; ; to zero and then back. This will cause an THR empty interrupt. ; ;--------------------------------------------------------------------------; CALL rsint_8250_bufw_int rsint_8250_bufw_noi: ; ;--------------------------------------------------------------------------; ; Finish up and get ready to loop again ; ;--------------------------------------------------------------------------; OR DX,DX ; Anything more to send? JZ rsint_8250_bufw_end ; Nope JMP rsint_8250_bufw_loop; Go loop ;--------------------------------------------------------------------------; ; Here is where we end ; ;--------------------------------------------------------------------------; rsint_8250_bufw_end: ; MOV buffer_t_in[SI],DI ; Save input pointer MOV SS:stack_cx[BX],DX ; Bytes remaining JMP rsint_8250_status ; Do a status ;==========================================================================; ; Case a false hardware interrupt on the chip. ; ;==========================================================================; ;--------------------------------------------------------------------------; ; If buffer was empty, cause a false hardware interrupt by setting the IIR ; ; to zero and then back. This will cause an THR empty interrupt. ; ;--------------------------------------------------------------------------; rsint_8250_bufw_int: ; MOV AL,hiv[SI] ; Get the hardware interrupt vector address ; MOV rsint_8250_bufw_int,AL ; Put it where we need it ; JMP $+2 ; Flush interrupt buffer ; INT 00H ; Interrupt! ; ORG $-1 ;sint_8250_bufw_int DB ? ; Place to put interrupt number ; CLI ; No interrupt please! MOV CX,DX ; Save DX MOV DX,baseaddr[SI] ; Get base address for chip ADD DX,ier_8250 ; Address IER IN AL,DX ; Get it MOV AH,AL ; Save it SUB AL,AL ; Now send zero OUT DX,AL ; to IER MOV AL,AH ; Now restore IER JMP $+2 ; Delay OUT DX,AL ; JMP $+2 ; Delay STI ; Enable MOV DX,CX ; Restore DX RET ;==========================================================================; ; Block read ; ;==========================================================================; rsint_8250_buffr: ; ;--------------------------------------------------------------------------; ; Initialize ; ;--------------------------------------------------------------------------; MOV BX,SP ; Need pointer for stack SUB DX,DX ; Number of bytes moved. ;--------------------------------------------------------------------------; ; This is the main move loop ; ; DX = total_bytes moved ; ;--------------------------------------------------------------------------; rsint_8250_bufr_loop: ;--------------------------------------------------------------------------; ; If no data left then we can leave ; ;--------------------------------------------------------------------------; MOV DI,buffer_r_out[SI] ; Get buffer output pointer MOV AX,buffer_r_in[SI] ; Get buffer input pointer CMP AX,DI ; See in anything in buffer JE rsint_8250_bufr_done ; Nope.. Quit ;--------------------------------------------------------------------------; ; Now get the data left in the buffer. ; ;--------------------------------------------------------------------------; MOV CX,AX ; CX = end of area to move CMP AX,DI ; Is the buffer wrapped? JGE rsint_8250_bufr_nw ; Not wrapped MOV CX,buffer_size ; Wrapped. Locate end for now rsint_8250_bufr_nw: SUB CX,DI ; CX = data left in buffer MOV AX,SS:stack_cx[BX] ; Get user's buffer size OR AX,AX ; Any space left? JZ rsint_8250_bufr_done ; Nope.. Quit ;--------------------------------------------------------------------------; ; Now calculate the size to move in this iteration. ; ; It will be the smallest of: ; ; 1) Data size (now in CX) ; ; 2) User's buffer size ; ;--------------------------------------------------------------------------; CMP CX,AX ; JLE rsint_8250_bufr_m1 ; MOV CX,AX ; rsint_8250_bufr_m1: ; ;--------------------------------------------------------------------------; ; Update counters now ; ;--------------------------------------------------------------------------; ADD DX,CX ; Bump bytes moved counter SUB AX,CX ; Show buffer usage MOV SS:stack_cx[BX],AX ; And store back ;--------------------------------------------------------------------------; ; Prep all the registers and do the move ; ;--------------------------------------------------------------------------; ASSUME DS:NOTHING; MOV AX,SI ; Save SI MOV DS,buffer_r_a[SI] ; Get buffer segment MOV SI,DI ; Set buffer offset MOV ES,SS:stack_es[BX] ; Get input segment MOV DI,SS:stack_di[BX] ; Get input offset CLD ; The counter should go up! REP MOVSB ; Do the move MOV SS:stack_di[BX],DI ; Put back updated offset. MOV DI,SI ; Restore an updated DI MOV SI,AX ; Restore SI MOV AX,CS ; Restore DS MOV DS,AX ; ASSUME DS: everything ; ;--------------------------------------------------------------------------; ; Update things ; ;--------------------------------------------------------------------------; CMP DI,buffer_size ; Wrap the input pointer around the JL rsint_8250_bufr_now ; buffer if necessary SUB DI,DI ; rsint_8250_bufr_now: ; MOV buffer_r_out[SI],DI ; Set buffer output pointer ;--------------------------------------------------------------------------; ; Loop back ; ;--------------------------------------------------------------------------; JMP rsint_8250_bufr_loop ; ;--------------------------------------------------------------------------; ; Here is where we end ; ;--------------------------------------------------------------------------; rsint_8250_bufr_done : ; MOV BX,SP ; Use SP in BX MOV SS:stack_cx[BX],DX ; Bytes moved JMP rsint_8250_status ; Do a status ;==========================================================================; ; WA8DED Mode ; ;==========================================================================; rsint_8250_ded: ; JMP rsint_exit ; All done