Ham Radio 2000 #1

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Assembly Source File | 1987-12-06 | 69.1 KB | 1,485 lines

;==========================================================================; ; 8530 Services ; ; ; ; Copyright 1986, 1987 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. ; ; ; ; Permission is explicity granted to use this code as a model for ; ; other programs requiring interrupt driven serial I/O as long as they ; ; carry this copyright notice and the imbedded constants ; ; ; ; These run disabled for the most part because of the nature of ; ; reading and writing the 8530. ; ; ; ; AL = parameter ; ; AH = opcode ; ; BL = COM number - 1 (0 = COM1, 1=COM2, ...) ; ; ; ; Opcode 0 -- Initialize ; ; Parms ; ; xxx..... = Data rate. Use same settings as IBM ROM BIOS. ; ; 300 bps = 2, 1200 bps= 4. ; ; ; ; ...x.... = Full duplex if 1. Half duplex if 0. ; ; ; ; ....x... = Error packet handler. 0 = throw away all error ; ; packets. ; ; ; ; .....xxx = Don't care. Use 0 for now! ; ; ; ; Special case -- If AL = 0 then the COM port is closed! ; ; ; ; Opcode 1+2 -- Same as ASYNC ports but conforms to KISS interface ; ; ; ; Opcode 3 -- Status ; ; No parms ; ; Returns AH. AL = 0 ; ; x.xxxxx. = not assigned. Zero ; ; .x...... = If 0 then packets remain in the transmit queue ; ; .......x = If 1 then packets await in the receive queue ; ; ; ; Opcode 10 -- Send a packet ; ; ES = Segment of buffer containing the packet to be sent. ; ; Note: The buffer pointed to by ES will be freed when the ; ; packet is sent. It should be gotten via Opcode 6. It must ; ; be 512 bytes long and conform to the layout of the buffers ; ; ; ; Opcode 11 -- Receive a packet ; ; Returns ES with segment of buffer containing the packet ; ; recieved. If zero, no such packet exists. ; ; ; ; Opcode 12 -- Buffer management ; ; If ES is zero then returns a buffer segment in ES. ; ; If ES is non-zero then the buffer pointed to is freed. ; ; ; ; Opcode 13 -- Set TXD -- time from RTS to start of packet. ; ; AL = new setting in clock counts ; ; ; ; Opcode 14 -- Set P -- Controls time from end of DCD to RTS ; ; AL = new setting. 1.0 = 255 ; ; ; ; Opcode 15 -- Set slot time -- Controls time from end of DCD to RTS ; ; AL = new setting in clock counts ; ; ; ; Opcode 16 -- Set CRC wait -- time from start of last character to drop ; ; RTS.. Should be 5 character lengths minimum ; ; AL = new setting in clock counts ; ; ; ;==========================================================================; rcvbuf_8530 EQU 00000001B ; Receive buffer has data in it txbuf_8530 EQU 10111111B ; Transmit buffer has data in it (inverted) CLI ; Interrupts off! MOV BL,AH ; Use BX so we can jump SUB BH,BH ; Use BX so we can jump CMP BL,16 ; Legal value? JA svc_8530_not_us ; Nope.. Pass on down SHL BL,1 ; *2 for words JMP DS:svc_8530_br[BX] ; Go where we gotta go svc_8530_not_us: ; JMP rsint_exit_not_us ; svc_8530_br LABEL WORD ; DW OFFSET rsint_8530_init ; 0 = Init DW OFFSET rsint_8530_kiss_t ; 1 = Send character DW OFFSET rsint_8530_kiss_r ; 2 = Rcv character DW OFFSET rsint_8530_status ; 3 = Status DW OFFSET rsint_8530_query ; 4 = Query DW OFFSET rsint_8530_ignore ; 5 = Nothing DW OFFSET rsint_8530_ignore ; 6 = Nothing DW OFFSET rsint_8530_ignore ; 7 = Nothing DW OFFSET rsint_8530_ignore ; 8 = Nothing DW OFFSET rsint_8530_ignore ; 9 = Nothing DW OFFSET rsint_8530_sendp ; 10 = Send Packet DW OFFSET rsint_8530_recvp ; 11 = Receive Packet DW OFFSET rsint_8530_buff ; 12 = Get/Free buffer DW OFFSET rsint_8530_txd ; 13 = Set TXD DW OFFSET rsint_8530_setp ; 14 = Set P DW OFFSET rsint_8530_slot ; 15 = Set slot DW OFFSET rsint_8530_crcwt ; 16 = Set CRC wait rsint_8530_ignore: MOV AX,0FFFFH ; All ones for error JMP rsint_exit ; ;==========================================================================; ; Inquiry ; ;==========================================================================; rsint_8530_query: MOV AX,0AA55H ; Set footprint JMP rsint_exit ; All done ;--------------------------------------------------------------------------; ; Speed tables for 8530 PACCOMM board. Entries are in the same order as ; ; original BIOS ; ; ; ; 1st table = Divisor when DPLL is on (X32 clock) ; ; 2nd table = Divisor when DPLL is off (X1 clock) ; ; 3nd table = Data rate table -- Type "B" card ; ; 4rd table = Modem setting -- 7910 -- Type "A" card ; ; 5th table = Modem setting -- 7910 -- Type "B" card ; ; 6th table = Modem setting -- TCM3105 -- Type "B" card ; ; ; ;--------------------------------------------------------------------------; divx32_8530 LABEL WORD ; 7910 clock data for X32 and 2.4576 xtal DW 015BH ; 110 bps - X32 clock - 0 DW 00FEH ; 150 bps - X32 clock - 1 DW 007EH ; 300 bps - X32 clock - 2 DW 003EH ; 600 bps - X32 clock - 3 DW 001EH ; 1200 bps - X32 clock - 4 DW 000EH ; 2400 bps - X32 clock - 5 DW 0006H ; 4800 bps - X32 clock - 6 DW 0002H ; 9600 bps - X32 clock - 7 divx1_8530 LABEL WORD ; 7910 clock data for X1 and 2.4576 Mhz xtal DW 26A0H ; 110 bps - X1 clock DW 1FFCH ; 150 bps - X1 clock DW 0FFCH ; 300 bps - X1 clock DW 07FEH ; 600 bps - X1 clock DW 03FEH ; 1200 bps - X1 clock DW 01FEH ; 2400 bps - X1 clock DW 00FEH ; 4800 bps - X1 clock DW 007EH ; 9600 bps - X1 clock divdr_8530 LABEL WORD ; Corresponds table value to data rate ; times 64 and divided by 10. Used to ; calculate divider setting DW 704 ; 110 bps DW 960 ; 150 bps DW 1920 ; 300 bps DW 3840 ; 600 bps DW 7680 ; 1200 bps DW 15360 ; 2400 bps DW 30720 ; 4800 bps DW 61440 ; 9600 bps modem_8530_a1 LABEL BYTE ; Type "A" card 7910 Modem bits... ; Bottom 4 bits are: ; MC3, MC2, MC1, MC0 ; The 7910 is on both channels DB 01H ; 110 bps - Modem setting -- 103 Answer DB 01H ; 150 bps - Modem setting -- 103 Answer DB 01H ; 300 bps - Modem setting -- 103 Answer DB 02H ; 600 bps - Modem setting -- 202 DB 02H ; 1200 bps - Modem setting -- 202 DB 02H ; 2400 bps - Modem setting -- 202 Probably DB 02H ; 4800 bps - Modem setting -- 202 won't DB 02H ; 9600 bps - Modem setting -- 202 work modem_8530_b1 LABEL BYTE ; Type "B" card 7910 Modem bits... ; Bottom 4 bits are: ; MC0, MC2, MC1, MC3 ; The 7910 is on "A" channel only DB 08H ; 110 bps - Modem setting -- 103 Answer DB 08H ; 150 bps - Modem setting -- 103 Answer DB 08H ; 300 bps - Modem setting -- 103 Answer DB 02H ; 600 bps - Modem setting -- 202 DB 02H ; 1200 bps - Modem setting -- 202 DB 02H ; 2400 bps - Modem setting -- 202 Probably DB 02H ; 4800 bps - Modem setting -- 202 won't DB 02H ; 9600 bps - Modem setting -- 202 work ; Note.. The high order bit controls loopback ; mode. It is forced on. All this does is ; make the tones use the same pair for both ; transmit and receive modem_8530_b2 LABEL BYTE ; Type "B" card TCM3105 Modem Bits ; Upper 4 bits are: ; special, TRS(thru J3), TXR1, TXR2 ; The 3105 is on "B" channel only ; The special bit is the 7910 loop back ; bit and we force it on! DB 00H ; Only one setting for this sucker! ; Bell 202, 1200 bps word_100 DW 100 ; This constant is here so we can divide later ;==========================================================================; ; Init.. ; ; The init character is similar to the one for BIOS ; ; xxx..... -- Baud rate. Same meanings as for BIOS ; ; ...000.. -- Must be zero! ; ; ......x. -- Passthru packets in error if on ; ; .......x -- Full duplex if on ; ; ; ; If AL is all zero then disable the channel ; ; ; ;==========================================================================; rsint_8530_init: ;--------------------------------------------------------------------------; ; Special check for off! If it is, do it ; ;--------------------------------------------------------------------------; OR AL,AL ; Turn off? JNZ rsint_8530_i_go ; Nope.. Initialize the thing AND flags,0FFH-flags_in_use ; This block is closed! MOV DX,baseaddr[SI] ; Get port address CALL off_8530 ; Disable this channel JMP rsint_exit ; Leave rsint_8530_i_go: ; MOV flags[SI],flags_in_use ; This block is open! ;--------------------------------------------------------------------------; ; Set options ; ;--------------------------------------------------------------------------; MOV BL,AL ; Get the options bits AND BL,00011111B ; Remove baud rate parameter MOV BH,options[SI] ; Get current options AND BH,11100000B ; Remove the ones we are about to set OR BL,BH ; Make new options byte MOV options[SI],BL ; And save ;--------------------------------------------------------------------------; ; Initialize the modem ; ;--------------------------------------------------------------------------; MOV DX,baseaddr[SI] ; Get port address MOV CL,5 ; Get baud rate parameter SHR AL,CL ; AND AX,07H ; MOV data_rate[SI],AL ; Save baud rate MOV BX,AX ; Put baud rate into work register MOV AH,modem_8530_a1[BX] ; Get the new modem setting for type "A" CMP type_8530[SI],type_8530_a ; Type "A" card? JE rsinit_8530_modem_do ; Yep! ; Must be a type "B" card to get here MOV AH,modem_8530_b1[BX] ; Get the new 7910 modem setting for "B" TEST DX,scc_chan_mask ; Channel "A" or "B" JNZ rsinit_8530_modem_do ; Channel "A" -- 7910! MOV AH,modem_8530_b2 ; Type "B" 3105 modem setting (only one) rsinit_8530_modem_do: ; AH = new modem setting when we get here MOV DI,chip_comm[SI] ; Get chip common pointer MOV AL,DS:4[DI] ; Get current byte setting TEST DX,scc_chan_mask ; Channel "A" or "B" JNZ rsinit_8530ia ; Channel "A" AND AL,0F0H ; Remove old channel "B" setting OR AL,AH ; Put in the modem setting JMP SHORT rsinit_8530_modem_set ; Go init the modem rsinit_8530ia: AND AL,0FH ; Remove old channel "A" setting MOV CL,4 ; SHL AH,CL ; Shift it to where it belongs OR AL,AH ; and form the new modem setting rsinit_8530_modem_set: MOV DS:4[DI],AL ; Save the new modem setting ; Channel A setting is in top half of AL ; Channel B setting is in bottom half of AL ; This is backwards for the "TYPE B" card CMP type_8530[SI],type_8530_a ; Type "A" card? JE rsinit_8530_modem_set2 ; Yep! MOV CL,4 ; Rotate the register to flip flop the ROR AL,CL ; A and B channels OR AL,10000000B ; Turn on M4 bit always. This forces the ; the 7910 into loopback mode. rsinit_8530_modem_set2: AND DX,scc_card_mask ; Back to address of card ADD DX,scc_modem ; Now change to modem address OUT DX,AL ; Set the modems ;--------------------------------------------------------------------------; ; Setup 8530 -- Register 9 -- Reset the channel.. ; ;--------------------------------------------------------------------------; MOV DX,baseaddr[SI] ; Get port address MOV AL,sccreg9 ; Point at WR9 OUT DX,AL ; MOV AL,chareset ; Guess Channel A reset TEST DX,scc_chan_mask ; Channel "A" or "B" JNZ rsinit_8530ra ; Channel "A" MOV AL,chbreset ; Wrong guess -- Channel B reset rsinit_8530ra: ; OUT DX,AL ; ;--------------------------------------------------------------------------; ; Setup 8530 -- Register 6 -- SDLC Address field ; ; None ; ;--------------------------------------------------------------------------; MOV DX,baseaddr[SI] ; Get port address MOV AL,sccreg6 ; Point at WR6 OUT DX,AL ; SUB AL,AL ; Zero OUT DX,AL ; ;--------------------------------------------------------------------------; ; Setup 8530 -- Register 7 -- SDLC Flag ; ; 01111110 ; ;--------------------------------------------------------------------------; MOV AL,sccreg7 ; WR7 OUT DX,AL ; MOV AL,01111110B ; OUT DX,AL ; ;------------------------------------+-------------------------------------; ; Setup 8530 -- Register 10 -- Data type ; ; CRC preset 1, NRZI, abort on underrun ; ;--------------------------------------------------------------------------; MOV AL,sccreg10 ; WR10 OUT DX,AL ; MOV AL,crc_1or0+nrzimode; OUT DX,AL ; ;--------------------------------------------------------------------------; ; Setup 8530 -- Register 4 -- Mode ; ; Use 01x, SDLC, no parity ; ;--------------------------------------------------------------------------; MOV AL,sccreg4 ; Point at WR4 OUT DX,AL ; MOV AL,x1_clck+sync_sdl+sync_mod ; OUT DX,AL ; Put out ;--------------------------------------------------------------------------; ; Setup 8530 -- If this is channel "A" and channel "B" has not been set ; ; then we have to init the clock registers over there to supply XTAL to ; ; everyone. This only applies to the PACCOMM type "A" card. ; ;--------------------------------------------------------------------------; MOV DI,chip_comm[SI] ; Get chip common pointer CMP type_8530[SI],type_8530_a ; Type "A" card (internal Osc)? JNE rsinit_8530cb ; Nope! TEST DX,scc_chan_mask ; Channel "A" or "B" JZ rsinit_8530cb ; Channel "B" CMP DS:BYTE PTR 5[DI],0 ; Channel "B" started? JNE rsinit_8530cb ; Channel "B" AND DL,0FFH-scc_chan_mask ; Channel "B" now MOV AL,sccreg11 ; Point at WR11 OUT DX,AL ; MOV AL,xtal_osc+rxc_brg+txc_brg+trxc_out+trxc_xtl ; OUT DX,AL ; Put out OR DL,scc_chan_mask ; Back to channel "A" rsinit_8530cb: MOV DS:BYTE PTR 5[DI],1 ; Channel "B" started! ;--------------------------------------------------------------------------; ; Setup 8530 -- Do the clock and receiver ; ;--------------------------------------------------------------------------; CALL ron_clk_8530 ; Receiver and clock setup ;--------------------------------------------------------------------------; ; Setup 8530 -- Register 5 ; ; DTR on, 8 bits for transmit, transmit CRC enable, tx enable ; ;--------------------------------------------------------------------------; MOV AL,sccreg5 ; Point at WR5 OUT DX,AL ; MOV AL,dtr_pin+tx_8bits+tx_crcen+tx_enabl ; OUT DX,AL ; Transmit ;--------------------------------------------------------------------------; ; Setup Interrupts ; ;--------------------------------------------------------------------------; CALL int_8530 ; ;--------------------------------------------------------------------------; ; Setup 8530 -- Register 9 -- Master interrupt control ; ; Enable, no vector, status wanted ; ;--------------------------------------------------------------------------; MOV AL,sccreg9 ; Point at WR9 OUT DX,AL ; MOV AL,int_enab+no_vectr+enab_vis ; OUT DX,AL ; ;--------------------------------------------------------------------------; ; Init all done ; ;--------------------------------------------------------------------------; JMP rsint_exit ; ;==========================================================================; ; Send a character in KISS mode ; ;==========================================================================; rsint_8530_kiss_t: MOV BX,buffer_t_in[SI] ; Get buffer counter ;--------------------------------------------------------------------------; ; This code handles the character after an escape ; ;--------------------------------------------------------------------------; TEST kiss_flag[SI],kiss_r_fesc ; Escape was previous? JZ rsint_8530_kt_nescp ; Nope.... CMP AL,kiss_tfesc ; Transposed FESC? JNE rsint_8530_kt_ntfesc ; Nope.... MOV AL,kiss_fesc ; Make an FESC JMP rsint_8530_kt_data ; and handle like data rsint_8530_kt_ntfesc: CMP AL,kiss_tfesc ; Transposed FEND? JNE rsint_8530_kt_nescp ; Nope.... Just pass thru MOV AL,kiss_fend ; Make an FEND JMP rsint_8530_kt_data ; and handle like data rsint_8530_kt_nescp: ;--------------------------------------------------------------------------; ; Check for FEND ; ;--------------------------------------------------------------------------; CMP AL,kiss_fend ; Is the incoming data FEND? JE rsint_8530_kt_isfend ; Yes..... JMP rsint_8530_kt_notfend ; Nope.... rsint_8530_kt_isfend: ;--------------------------------------------------------------------------; ; Incoming character is FEND.. It either starts or ends a packet. ; ;--------------------------------------------------------------------------; OR BX,BX ; Is buffer counter zero? JNZ rsint_8530_kt_notstart ; No... Must be an end of frame JMP rsint_8530_kt_start ; Yes.. Must be a start of frame rsint_8530_kt_notstart: ;--------------------------------------------------------------------------; ; Incoming character is FEND.. It ends a packet... ; ;--------------------------------------------------------------------------; CMP kiss_type[SI],kiss_data ; Is this a data packet JNE rsint_8530_kt_cmd ; Nope... Its a command MOV ES,buffer_t_seg[SI] ; Get buffer's address MOV ES:buffer_dl,BX ; Set length MOV buffer_t_seg[SI],0 ; Clear buffer pointer MOV buffer_t_in[SI],0 ; Clear buffer counter JMP rsint_8530_sendp ; Send the packet ;--------------------------------------------------------------------------; ; This code handles a stream from the host that has a KISS command and ; ; not data in it. ; ;--------------------------------------------------------------------------; rsint_8530_kt_cmd: MOV buffer_t_in[SI],0 ; Clear buffer counter AND kiss_flag[SI],0FFH-kiss_r_fesc ; Turn off escape flag TEST kiss_flag[SI],kiss_t_valid ; Type valid? JZ rsint_8530_kt_i ; No.... Ignore packet AND kiss_flag[SI],0FFH-kiss_t_valid ; Turn off type flag MOV BL,kiss_type[SI] ; Get type CMP BL,kiss_fesc ; Is this an escape command JE rsint_8530_kt_i ; Yes... Ignore packet MOV ES,buffer_t_seg[SI] ; Get the buffer address MOV AL,ES:0 ; Get the data byte SUB AH,AH ; Clear type of the word SUB BH,BH ; Make the type a word DEC BL ; Base of index = 1 so make 0 SHL BL,1 ; And make it address a word JMP DS:rsint_8530_kt_j[BX] ; Go where we gotta go rsint_8530_kt_j LABEL WORD ; DW OFFSET rsint_8530_kt_txd ; 1 = TXD DW OFFSET rsint_8530_kt_p ; 2 = P DW OFFSET rsint_8530_kt_slot ; 3 = Slot time DW OFFSET rsint_8530_kt_crc ; 4 = TxTail (CRC time) DW OFFSET rsint_8530_kt_fds ; 5 = Full duplex switch DW OFFSET rsint_8530_kt_i ; 6 = Set link speed rsint_8530_kt_i: ; Come here to ignore the command JMP rsint_8530_status ; five DB 5 ; Needed for divide rsint_8530_kt_txd: ; Set TXD - value in 10ms increments ADD AL,3 ; Change value to 50ms increments. This DIV five ; is close to our 54ms clock pulses CBW ; Need to store a word OR AX,AX ; Don't store zero! JNZ rsint_8530_kt_txd_ok; If the user tries this, MOV AX,1 ; use 1 instead rsint_8530_kt_txd_ok: MOV value_txd[SI],AX ; Set TXD JMP rsint_8530_status ; Exit rsint_8530_kt_p: ; Set P MOV value_p[SI],AL ; JMP rsint_8530_status ; Exit rsint_8530_kt_slot: ; Set Slot time - value in 10ms increments ADD AL,3 ; Change value to 50ms increments. This DIV five ; is close to our 54ms clock pulses OR AL,AL ; Don't store zero! JNZ rsint_8530_kt_slot_ok; If the user tries this, MOV AL,1 ; use 1 instead rsint_8530_kt_slot_ok: MOV value_slot[SI],AL ; Set slot JMP rsint_8530_status ; Exit rsint_8530_kt_crc: ; Set CRC - value in 10ms increments ADD AL,3 ; Change value to 50ms increments. This DIV five ; is close to our 54ms clock pulses CBW ; Need to store a word OR AX,AX ; Don't store zero! JNZ rsint_8530_kt_crc_ok; If the user tries this, MOV AX,1 ; use 1 instead rsint_8530_kt_crc_ok: MOV value_crc[SI],AX ; Set CRC JMP rsint_8530_status ; Exit rsint_8530_kt_fds: ; Set full duplex switch MOV AH,options[SI] ; Get options switch AND AH,0FFH-opt_fd ; Remove old setting OR AL,AL ; Turn switch on or off? JZ rsint_8530_kt_fds_0 ; Switch is off OR AH,opt_fd ; Switch is on rsint_8530_kt_fds_0: MOV options[SI],AH ; Put the switch back JMP rsint_8530_status ; Exit ;--------------------------------------------------------------------------; ; Incoming character is FEND.. It may start a packet ; ;--------------------------------------------------------------------------; rsint_8530_kt_start: ; AND kiss_flag[SI],0FFH-kiss_t_valid-kiss_r_fesc ; Turn off type ; and escape flags MOV kiss_type[SI],kiss_escape ; Set type to escape JMP rsint_8530_status ; Send staus back ;--------------------------------------------------------------------------; ; Incoming character is not FEND.. Handle first character in packet if it ; ; is one ; ;--------------------------------------------------------------------------; rsint_8530_kt_notfend: OR BX,BX ; Is buffer counter zero? JNZ rsint_8530_kt_data ; No... Can't be first byte. Its data TEST kiss_flag[SI],kiss_t_valid ; Type loaded? JNZ rsint_8530_kt_data ; Yes.. This is the first data byte CMP AL,kiss_escape ; Is this KISS escape JE rsint_8530_kt_okt ; Yep... Type ok CMP AL,kiss_last_type ; Is this within the valid modes? JBE rsint_8530_kt_okt ; Yep... Mode ok MOV AL,kiss_escape ; Invalid type.. Use escape rsint_8530_kt_okt: MOV kiss_type[SI],AL ; Set the incoming data type OR kiss_flag[SI],kiss_t_valid ; Type valid JMP rsint_8530_status ; Go send status ;--------------------------------------------------------------------------; ; This code handles data characters ; ;--------------------------------------------------------------------------; rsint_8530_kt_data: CMP BX,buffer_siz2 ; Will we overflow the buffer? JA rsint_8530_kt_done ; Yes.... Ignore the character MOV DX,buffer_t_seg[SI] ; Get the buffer address MOV ES,DX ; OR DX,DX ; Is there one? JNZ rsint_8530_kt_sdata ; Yes... Use it MOV DL,AL ; Save incoming data CALL get_a_buffer ; Get the new buffer for the chain OR AX,AX ; Did we find one? JZ rsint_8530_kt_done ; NO.. Ignore the character MOV buffer_t_seg[SI],AX ; Set the buffer address MOV ES,AX ; Set the registers straight MOV AL,DL ; rsint_8530_kt_sdata: MOV ES:0[BX],AL ; Save the data byte INC BX ; Bump counter and MOV buffer_t_in[SI],BX ; save rsint_8530_kt_done: JMP rsint_8530_status ; Leave ;==========================================================================; ; Receive a character in KISS mode ; ;==========================================================================; rsint_8530_kiss_r: ;--------------------------------------------------------------------------; ; See if we have something in progress. If we do then that is goodness. ; ; If not we have to check the whole queue. This simply shortcuts the ; ; need to search the whole queue every time. ; ;--------------------------------------------------------------------------; MOV ES,buffer_r_seg[SI] ; Get the shortcut buffer address MOV AX,ES ; Now put it somewhere handy OR AX,AX ; Anything there? JNZ rsint_8530_kr_do ; Yep... Take the shortcut ;--------------------------------------------------------------------------; ; See if we have anything. We loop here if nothing doing. Enable ; ; interrupts to permit something to work. ; ;--------------------------------------------------------------------------; STI ; Interrupt enable rsint_8530_kr_loop1: MOV ES,buffer_r_a[SI] ; Get the current buffer address MOV AX,ES:buffer_next ; Get head of queue OR AX,AX ; Anything in queue? JZ rsint_8530_kr_loop1 ; Yep.. Go process it ;--------------------------------------------------------------------------; ; Ok! Something is here.. We now have to scurry down the queue to find ; ; the last entry because it is the oldest! Disable interrupts to prevent ; ; someone from messing with it ; ;--------------------------------------------------------------------------; CLI ; Interrupt disable MOV ES,buffer_r_a[SI] ; Get the current buffer address MOV BX,ES ; Save this! MOV ES,ES:buffer_next ; Get head of queue rsint_8530_kr_loop2: MOV AX,ES:buffer_next ; Get --> to next in queue OR AX,AX ; Anything there? JZ rsint_8530_kr_found ; Nope.. Found end of queue MOV BX,ES ; Save last MOV ES,AX ; Point to next JMP rsint_8530_kr_loop2 ; Loop back for more rsint_8530_kr_found: STI ; Reenable interrupts MOV buffer_r_seg[SI],ES ; Set it up for shortcut next time. JMP SHORT rsint_8530_kr_fs ; Go send beginning FEND ;--------------------------------------------------------------------------; ; ES now points to a buffer with our data in it. Get current mode ; ; and go to it. ; ;--------------------------------------------------------------------------; rsint_8530_kr_do: MOV BL,kiss_flag[SI] ; Get the KISS-R mode AND BL,kiss_r_mode ; SUB BH,BH ; JMP DS:rsint_8530_krjmp[BX] ; Go where we gotta go rsint_8530_krjmp LABEL WORD ; Branch table DW OFFSET rsint_8530_kr_fs ; 0 = Start packet FEND DW OFFSET rsint_8530_kr_type ; 1 = Type DW OFFSET rsint_8530_kr_data ; 2 = Data DW OFFSET rsint_8530_kr_fe ; 3 = End packet FEND rsint_8530_kr_modes: ; Subroutine to set KISS-R mode MOV AL,kiss_flag[SI] ; Get the whole flag byte AND AL,0FFH-kiss_r_mode ; Remove the current mode setting OR AL,BL ; Put new one in MOV kiss_flag[SI],AL ; Put byte pack RET ; Return to caller ;--------------------------------------------------------------------------; ; Start a packet by sending FEND ; ;--------------------------------------------------------------------------; rsint_8530_kr_fs: ; Start packet FEND MOV buffer_r_out[SI],0 ; Clear output pointer MOV BL,kiss_r_mtype ; Set mode to data CALL rsint_8530_kr_modes ; MOV AX,kiss_fend ; Output FEND. We zero AH this way too.. JMP rsint_8530_status_ah ; Go load AH status data. ;--------------------------------------------------------------------------; ; Send the packet type ; ;--------------------------------------------------------------------------; rsint_8530_kr_type: ; Start packet FEND MOV AX,kiss_data ; Signal data frame -- zero AX this way MOV BL,kiss_r_mdata ; Set mode to data CALL rsint_8530_kr_modes ; JMP rsint_8530_status_ah ; Go load AH status data. ;--------------------------------------------------------------------------; ; Send packet data. Don't forget check for special characters ; ;--------------------------------------------------------------------------; rsint_8530_kr_data: ; Send packet data MOV AX,kiss_fesc ; Clear AH for call to status ; Set AL to escape if needed MOV BX,buffer_r_out[SI] ; Get output pointer MOV DL,ES:[BX] ; Get a data byte CMP DL,kiss_fend ; Data is FEND? JE rsint_8530_kr_dfend ; YES... Escape needed. CMP DL,kiss_fesc ; Data is FESC? JE rsint_8530_kr_dfesc ; YES... Escape needed. MOV AL,DL ; Regular data, let it go INC BX ; Increment pointer CMP BX,ES:buffer_dl ; Are we at the end of the data in buffer JAE rsint_8530_kr_end ; Yes.... MOV buffer_r_out[SI],BX ; Save new output pointer JMP rsint_8530_status_ah ; Go load AH status data. ; End of buffer detected. rsint_8530_kr_end: ; End of buffer but last data char in AL MOV BL,kiss_r_mfe ; Set mode to ending FEND CALL rsint_8530_kr_modes ; JMP rsint_8530_status_ah ; Go load AH status data. ; FEND found in data rsint_8530_kr_dfend: ; FEND in data stream MOV BYTE PTR ES:[BX],kiss_tfend ; Make the data a transposed FEND ; AL already has an FESC in it. Don't ; bump the pointer so we will send TFEND JMP rsint_8530_status_ah ; Go load AH status data. ; FESC found in data rsint_8530_kr_dfesc: ; FESC in data stream MOV BYTE PTR ES:[BX],kiss_tfesc ; Make the data a transposed FESC ; AL already has an FESC in it. Don't ; bump the pointer so we will send TFESC JMP rsint_8530_status_ah ; Go load AH status data. ;--------------------------------------------------------------------------; ; Send ending FEND and free everything up ; ;--------------------------------------------------------------------------; rsint_8530_kr_fe: MOV buffer_r_out[SI],0 ; Clear output pointer MOV buffer_r_seg[SI],0 ; Clear shortcut buffer address CLI ; Disable interrupts MOV ES,buffer_r_a[SI] ; Get the current buffer address MOV BX,ES ; rsint_8530_kr_feloop1: MOV AX,ES:buffer_next ; Get --> to next in queue OR AX,AX ; Anything there? JZ rsint_8530_kr_fefnd ; Nope.. Found end of queue MOV BX,ES ; Save last MOV ES,AX ; Point to next JMP rsint_8530_kr_feloop1 ; Loop back for more rsint_8530_kr_fefnd: ; ES = address of buffer we are finishing ; BX = buffer that points to one in ES MOV AX,ES ; Free this buffer CALL free_a_buffer ; Free a buffer instead MOV ES,BX ; Go back one buffer MOV ES:buffer_next,0 ; and zero his pointer STI ; Reenable interrupts MOV AX,kiss_fend ; Send FEND JMP rsint_8530_status_ah ; Go load AH status data. ;==========================================================================; ; Send a packet -- ES points to buffer to be sent. ; ;==========================================================================; rsint_8530_sendp: MOV ES:buffer_next,0 ; Put a zero in next buffer address ;--------------------------------------------------------------------------; ; See if queue is empty. If so this packet is the whole queue. We also ; ; need to attempt to turn on the transmitter ; ;--------------------------------------------------------------------------; MOV AX,buffer_t_a[SI] ; Get the transmit buffer address OR AX,AX ; Is there one? JNZ rsint_8530_sendp_q ; Yes. Must add this packet to the q ; This buffer is the whole queue. Put at the head MOV buffer_t_a[SI],ES ; Put this buffer on head of queue MOV ES:buffer_next,AX ; Put a zero in next buffer address ; Now try to turn on the transmitter TEST flags[SI],flags_xmt_on ; Transmitter on? JNZ rsint_8530_sendp_x ; Yes.. Don't do anything TEST options[SI],opt_fd ; Full duplex? JNZ rsint_8530_sendp_t ; Yes.. Go turn on transmitter TEST flags[SI],flags_dcd_on ; DCD on? JNZ rsint_8530_sendp_x ; Yes.. Don't do anything MOV AX,timer_dcd[SI] ; Get timer CMP AL,value_slot[SI] ; Slot expired? JB rsint_8530_sendp_x ; No... Don't do anything CALL random ; Get a random number CMP AL,value_p[SI] ; Check against "P" (the probability) JA rsint_8530_sendp_x ; Too big... Don't do anything ; Turn on transmitter rsint_8530_sendp_t: ; MOV DX,baseaddr[SI] ; Get port address CALL ton_clk_8530 ; Call the transmitter routine ; Do nothing rsint_8530_sendp_x: ; JMP rsint_exit ; Leave ;--------------------------------------------------------------------------; ; Add this packet to the transmit queue. ; ;--------------------------------------------------------------------------; rsint_8530_sendp_q: ; MOV BX,ES ; Save address of buffer to add to queue ; Loop around to find end of chain rsint_8530_sendp_loop: MOV ES,AX ; Address of buffer to test MOV AX,ES:buffer_next ; Get next one in chain OR AX,AX ; Anything left? JNZ rsint_8530_sendp_loop ; Yep.. Try again MOV ES:buffer_next,BX ; Add to chain JMP rsint_exit ; Leave ;==========================================================================; ; Receive a packet ; ;==========================================================================; rsint_8530_recvp: ;--------------------------------------------------------------------------; ; See if we have anything. We loop here if nothing doing. Enable ; ; interrupts to permit something to work. ; ;--------------------------------------------------------------------------; STI ; Interrupt enable rsint_8530_recvp_loop1: MOV ES,buffer_r_a[SI] ; Get the current buffer address MOV AX,ES:buffer_next ; Get head of queue OR AX,AX ; Anything in queue? JZ rsint_8530_recvp_loop1 ; Yep.. Go process it ;--------------------------------------------------------------------------; ; Ok! Something is here.. We now have to scurry down the queue to find ; ; the last entry because it is the oldest! Disable interrupts to prevent ; ; someone from messing with it ; ;--------------------------------------------------------------------------; CLI ; Interrupt disable MOV ES,buffer_r_a[SI] ; Get the current buffer address MOV BX,ES ; Save this! MOV ES,ES:buffer_next ; Get head of queue rsint_8530_recvp_loop2: MOV AX,ES:buffer_next ; Get --> to next in queue OR AX,AX ; Anything there? JZ rsint_8530_recvp_done ; Nope.. Found end of queue MOV BX,ES ; Save last MOV ES,AX ; Point to next JMP rsint_8530_recvp_loop2 ; Loop back for more rsint_8530_recvp_done: ;--------------------------------------------------------------------------; ; Found the last item in the chain. Remove it from the queue and give ; ; it back to the user! ; ;--------------------------------------------------------------------------; MOV AX,ES ; This is the guy with the oldest data MOV ES,BX ; Restore the old pointer. This is the MOV ES:buffer_next,0 ; guy who contains the pointer we must zero! ;--------------------------------------------------------------------------; ; All done ; ;--------------------------------------------------------------------------; JMP rsint_exit ; ;==========================================================================; ; Status.. ; ;==========================================================================; rsint_8530_status: SUB AX,AX ; No status so far! rsint_8530_status_ah: ; This entry point used to set AH only. ; This is for when data is in AL. AH ; must be zero to use this entry point. MOV ES,buffer_r_a[SI] ; Get the current rcvr buffer address MOV BX,ES:buffer_next ; Get head of queue OR BX,BX ; Any packets waiting in receive buffer? JZ rsint_8530_statnor ; Nope... OR AH,rcvbuf_8530 ; Yep.... turn on low order bit rsint_8530_statnor: ; MOV BX,buffer_t_a[SI] ; Get the current xmit buffer address AND AH,txbuf_8530 ; Turn off the empty transmit bit OR BX,BX ; Any packets in transmit queue? JNZ rsint_8530_statnot ; Yep.... OR AH,0FFH-txbuf_8530 ; Turn on the empty transmit bit rsint_8530_statnot: ; JMP rsint_exit ; ;==========================================================================; ; Buffer control - Get/Free ; ;==========================================================================; rsint_8530_buff: MOV AX,ES ; Put it in parameter register OR AX,AX ; Did user supply an address JZ rsint_8530_get ; No.. Get him a buffer CALL free_a_buffer ; Free a buffer instead JMP rsint_exit ; rsint_8530_get: CALL get_a_buffer ; JMP rsint_exit ; ;==========================================================================; ; Set Timing values.. TXD, P, SLOT, CRC wait ; ;==========================================================================; rsint_8530_txd: SUB AH,AH ; Clear high order byte MOV value_txd[SI],AX ; Set value JMP rsint_exit ; rsint_8530_setp: OR AL,AL ; Can't set zero! JZ rsint_8530_setp_0 ; MOV value_p[SI],AL ; Set value rsint_8530_setp_0: ; JMP rsint_exit ; rsint_8530_slot: MOV value_slot[SI],AL ; Set value JMP rsint_exit ; rsint_8530_crcwt: SUB AH,AH ; Clear high order byte MOV value_crc[SI],AX ; Set value JMP rsint_exit ; ;==========================================================================; ;==========================================================================; ;==========================================================================; ; 8530 Service subroutines. Used by both the Service and the interrupt ; ; handlers ; ;==========================================================================; ;==========================================================================; ; 8530 Interrupt control ; ;==========================================================================; int_8530: ;--------------------------------------------------------------------------; ; Basic setup for R15 is DCD. ; ;--------------------------------------------------------------------------; MOV AL,sccreg15 ; Point at WR15 OUT DX,AL ; MOV AL,dcd_ie ; ;--------------------------------------------------------------------------; ; If we have are receiving, want break/abort! ; ;--------------------------------------------------------------------------; TEST flags[SI],flags_dcd_on ; Receiver on? JZ int_8530_no_rx1 ; Nope.. OR AL,rxie_brk ; Want abort/break! int_8530_no_rx1: ;--------------------------------------------------------------------------; ; If we have are transmitting data then we want TX underruns ; ;--------------------------------------------------------------------------; TEST flags[SI],flags_xmt_on ; Transmitter on? JZ int_8530_no_tx1 ; Nope.. CMP period_xmtr[SI],period_x_tx ; Event = sending data JNE int_8530_no_tx1 ; Nope.. OR AL,txie_eom ; Add eom interrupt int_8530_no_tx1: ;--------------------------------------------------------------------------; ; Now set R15 ; ;--------------------------------------------------------------------------; OUT DX,AL ; ;--------------------------------------------------------------------------; ; Basic setup for R1 is external ; ;--------------------------------------------------------------------------; MOV AL,sccreg1 ; Point at WR1 OUT DX,AL ; MOV AL,exi_enab ; ;--------------------------------------------------------------------------; ; If we are transmitting data then we want TX ; ;--------------------------------------------------------------------------; TEST flags[SI],flags_xmt_on ; Transmitter on? JZ int_8530_no_tx2 ; Nope.. CMP period_xmtr[SI],period_x_tx ; Event = sending data JNE int_8530_no_tx2 ; Nope.. OR AL,txi_enab ; Add Tx Interrupt Master Enable int_8530_no_tx2: ;--------------------------------------------------------------------------; ; If we are receiving data then we want RX ; ;--------------------------------------------------------------------------; TEST flags[SI],flags_dcd_on ; Receiver on? JZ int_8530_no_rx2 ; Nope.. OR AL,rxi_all ; Add Rx Interrupt Master Enable int_8530_no_rx2: ;--------------------------------------------------------------------------; ; Now set R1 ; ;--------------------------------------------------------------------------; OUT DX,AL ; ;--------------------------------------------------------------------------; ; Done.. ; ;--------------------------------------------------------------------------; RET ; ;==========================================================================; ; 8530 Ready receiver and clock -- Use only on initialization and on ; ; half duplex links. Will destroy timing... ; ; ; ; Type "B" card is assumed full-duplex as far as clocking. ; ; ; ; Seconadry entry point: ; ; ; ; 8530 Ready receiver -- Does not destroy timing ; ;==========================================================================; ron_clk_8530: ;--------------------------------------------------------------------------; ; Setup 8530 -- Register 11 -- Oscillator ; ; ; ; Type "A" ; ; For channel "B": ; ; Use Crystal, Clock both rx and tx from DPLL, output xtal on TRXC ; ; For channel "A": ; ; Use Clock both rx and tx from DPLL ; ; ; ; Type "B" ; ; Rx clock = DPLL, tx clock is RTXC, output BRG on TRXC ; ;--------------------------------------------------------------------------; MOV AL,sccreg11 ; Point at WR11 OUT DX,AL ; ; Guess at type B MOV AL,rxc_dpll+txc_rtxc+trxc_out+trxc_brg ; Type "B" card setting CMP type_8530[SI],type_8530_a ; Type "A" card (internal Osc)? JNE ron_clk_8530bb ; Nope.. Guessed right ; Type "A" card setting TEST DX,scc_chan_mask ; Channel "A" or "B" JZ ron_clk_8530b1 ; "B"! MOV AL,rxc_dpll+txc_dpll ; Setting for "A" JMP SHORT ron_clk_8530bb ; ron_clk_8530b1: MOV AL,xtal_osc+rxc_dpll+txc_dpll+trxc_out+trxc_xtl ; ; Output the clock setting ron_clk_8530bb: OUT DX,AL ; Put out ;--------------------------------------------------------------------------; ; Setup 8530 -- Register 12 and 13 ; ; 12 = Lower byte of divisor ; ; 13 = Upper byte of divisor ; ; ; ; For type "A" card with internal oscillator, use tables ; ; ; ; For type "B" card with external oscillator, use the equation. ; ; ; ; 32*data_rate = 1 / (brg+2) * clock period ; ; ; ;--------------------------------------------------------------------------; MOV AL,sccreg12 ; Point at WR12 OUT DX,AL ; MOV BL,data_rate[SI] ; Get the data rate SUB BH,BH ; Zero high order byte SHL BL,1 ; *2 for a word lookup CMP type_8530[SI],type_8530_a ; Type "A" card (internal Osc)? JNE ron_clk_8530_bdiv ; Nope.. Guessed right ron_clk_8530_adiv: ; Clock setting for 8530 Type "A" card MOV AX,divx32_8530[BX] ; Get the whole divisor JMP SHORT ron_clk_8530_dive ; Go set the rate ron_clk_8530_bdiv: ; Clock setting for 8530 Type "B" card PUSH DX ; We are gonna lose him on the MUL/DIV MOV AX,clock_8530[SI] ; Get the clock frequency in Khz MUL word_100 ; Multiply by hundred DIV divdr_8530[BX] ; Divide by datarate table (which is DEC AX ; already divided by 10. The result is DEC AX ; the baud rate generator setting in AX ; but we still must subtract 2 POP DX ; Ooopss lost DX is shuffle so get it back ron_clk_8530_dive: ; Divisor info in AX so set it OUT DX,AL ; Put out lower byte MOV AL,sccreg13 ; Point at WR13 OUT DX,AL ; MOV AL,AH ; Get the upper divisor OUT DX,AL ; Put out lower byte ;--------------------------------------------------------------------------; ; Setup 8530 -- Register 14 -- DPLL ; ; This register has both commands and bit functions ; ; 1) NRZI mode ; ; 2) DPLL source = BRG ; ; 3) Start the BRG ; ; ; ; If type "B" card, keep selecting BRG in from PCC ; ; ; ; The rest of WR14 setup happens after the Secondary Entry Point! ; ; ; ;--------------------------------------------------------------------------; SUB AH,AH ; Assume type "A" card CMP type_8530[SI],type_8530_a ; Type "A" card (internal Osc)? JE ron_clk_8530_brgrtxc1 ; Yep.. MOV AH,brg_clck ; Set BRG clock in = PCC ron_clk_8530_brgrtxc1: ; Come here when BRG source is RTXC MOV AL,sccreg14 ; Point at WR14 OUT DX,AL ; MOV AL,mod_nrzi ; Command -> NRZI OR AL,AH ; BRG source bit as determined above OUT DX,AL ; MOV AL,sccreg14 ; Point at WR14 OUT DX,AL ; MOV AL,dpll_brg ; Command -> DPLL source = BRG OR AL,AH ; BRG source bit as determined above OUT DX,AL ; MOV AL,sccreg14 ; Point at WR14 OUT DX,AL ; MOV AL,enab_brg ; Start BRG OR AL,AH ; BRG source bit as determined above OUT DX,AL ; ;--------------------------------------------------------------------------; ; Secondary entry point is here. This is used to start receiving when ; ; DCD appears for example! It assumes the clocks are already set. ; ;--------------------------------------------------------------------------; ron_8530: ;--------------------------------------------------------------------------; ; Setup 8530 -- Register 14 -- DPLL ; ; This register has both commands and bit functions ; ; 1) Put DPLL in search mode. Start the BRG ; ;--------------------------------------------------------------------------; SUB AH,AH ; Assume type "A" card CMP type_8530[SI],type_8530_a ; Type "A" card (internal Osc)? JE ron_clk_8530_brgrtxc2 ; Yep.. MOV AH,brg_clck ; Set BRG clock in = PCC ron_clk_8530_brgrtxc2: ; Come here when BRG source is RTXC MOV AL,sccreg14 ; Point at WR14 OUT DX,AL ; MOV AL,dpllsrch+enab_brg ; Command -> DPLL search + start BRG OR AL,AH ; BRG source bit as determined above OUT DX,AL ; ;--------------------------------------------------------------------------; ; Setup 8530 -- Register 0 and 3 ; ; Use the write to WR0 to reset the receive CRC also ; ; ; ; 8 bits for receive, rx CRC enable. If DCD active then ; ; add hunting and rx enable. ; ;--------------------------------------------------------------------------; MOV AL,rst_rcrc ; Reset RX CRC OUT DX,AL ; MOV AL,sccreg3 ; Point at WR3 OUT DX,AL ; MOV AL,rx_8bits+rx_crcon ; TEST flags[SI],flags_dcd_on ; DCD on? JZ ron_8530_nodcd1 ; Nope OR AL,hunt_on+rx_enabl ; Yep.. Enable Rx and hunt ron_8530_nodcd1: ; OUT DX,AL ; ;--------------------------------------------------------------------------; ; Setup Interrupt control and go ; ;--------------------------------------------------------------------------; CALL int_8530 ; RET ; Done ;==========================================================================; ; 8530 Off -- Disable this port on the 8530. ; ;==========================================================================; off_8530: MOV AL,sccreg1 ; Point at WR1 OUT DX,AL ; SUB AL,AL ; OUT DX,AL ; Put out MOV AL,sccreg15 ; Now to WR15 OUT DX,AL ; SUB AL,AL ; Disable all interrupts! OUT DX,AL ; RET ; ;==========================================================================; ; 8530 Ready transmitter and clock. ; ; Type "A" card: ; ; For half duplex lines, switch crystal and slow down ; ; Full duplex uses DPLL timing so don't mess with clocks ; ; Type "B" card: ; ; The output of the BRG is routed thru an external divide-by-32 ; ; circuit and then used as the transmitter clock. No changes ; ; are needed when going from receive to transmit and vice versa. ; ;==========================================================================; ton_clk_8530: CMP type_8530[SI],type_8530_a ; Type "A" card (internal Osc)? JNZ ton_clk_8530_fd ; No... Dont mess with clocks TEST options[SI],opt_fd ; Full duplex? JNZ ton_clk_8530_fd ; Yes.. Dont mess with clocks ;--------------------------------------------------------------------------; ; Setup 8530 -- Register 11 -- Oscillator ; ; Use Crystal, Clock both rx and tx from BRG, output xtal on TRXC ; ;--------------------------------------------------------------------------; MOV AL,sccreg11 ; Point at WR11 OUT DX,AL ; TEST DX,scc_chan_mask ; Channel "A" or "B" JZ ton_clk_8530b1 ; "B"! MOV AL,rxc_brg+txc_brg ; Setting for "A" JMP SHORT ton_clk_8530bb ; ton_clk_8530b1: MOV AL,xtal_osc+rxc_brg+txc_brg+trxc_out+trxc_xtl ; ton_clk_8530bb: OUT DX,AL ; Put out ;--------------------------------------------------------------------------; ; Setup 8530 -- Register 12 and 13 ; ; 12 = Lower byte of divisor ; ; 13 = Upper byte of divisor ; ;--------------------------------------------------------------------------; MOV AL,sccreg12 ; Point at WR12 OUT DX,AL ; MOV BL,data_rate[SI] ; Get the data rate SUB BH,BH ; Zero high order byte SHL BL,1 ; *2 for a word lookup MOV AX,divx1_8530[BX] ; Get the whole divisor OUT DX,AL ; Put out lower byte MOV AL,sccreg13 ; Point at WR13 OUT DX,AL ; MOV AL,AH ; Get the upper divisor OUT DX,AL ; Put out lower byte ;--------------------------------------------------------------------------; ; Setup 8530 -- Register 14 -- DPLL ; ; This register has both commands and bit functions ; ; Start brg ; ;--------------------------------------------------------------------------; MOV AL,sccreg14 ; Point at WR14 OUT DX,AL ; MOV AL,enab_brg ; Start BRG OUT DX,AL ; Note: Didn't woory about BRG source ; Since we don't got thru this code for ; A type "B" card ;--------------------------------------------------------------------------; ; Next code is common for both Full and Half Duplex ; ;--------------------------------------------------------------------------; ton_clk_8530_fd: ;--------------------------------------------------------------------------; ; Setup 8530 -- Register 5 -- Transmitter control ; ; DTR, 8bits, TX enable, RTS, CRC ; ;--------------------------------------------------------------------------; MOV AL,sccreg5 ; Point at WR5 OUT DX,AL ; MOV AL,dtr_pin+tx_8bits+tx_enabl+rts_pin+tx_crcen ; OUT DX,AL ; ;--------------------------------------------------------------------------; ; Set flags and stuff ; ;--------------------------------------------------------------------------; OR flags[SI],flags_xmt_on ; Transmitter on! MOV period_xmtr[SI],period_x_txd ; Event = TXD delay MOV timer_xmtr[SI],0 ; Set transmitter timer to zero ;--------------------------------------------------------------------------; ; Setup Interrupt control and go ; ;--------------------------------------------------------------------------; CALL int_8530 ; RET ;