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;=======================================================================
;
; XMHB.Z80 - XMODEMXX PATCH FILE FOR ROMWBW HBIOS
;
; Wayne Warthen - wwarthen@gmail.com
; Updated: 2017-11-08
;
;=======================================================================
;
; Overlay file is Z80, build with M80:
; M80 =XMHB
; L80 XMHB,XMHB/N/X/E
;
.Z80
ASEG
;
NO EQU 0
YES EQU NOT NO
;
ERRDET EQU NO ; detect parity/framing/overrun errs
;
BASE EQU 100H ; start of cp/m normal program area
;
BDOS EQU 00005H ; BDOS function dispatch vector
;
;=======================================================================
;
; Jump table: The jump table must be in exactly the same sequence as the
; one in XMODEM. Note the ORG of 103H - This jump table has no jump to
; 'BEGIN'.
;
ORG BASE + 3 ;start after 'JMP BEGIN'
;
JP CONOUT ;must be 00000h if not used, see below
JP MINIT ;initialization routine (if needed)
JP UNINIT ;undo whatever 'MINIT' did (or return)
JPTBL:
JP SENDR ;send character (via pop psw)
JP CAROK ;test for carrier
JP MDIN ;receive data byte
JP GETCHR ;get character from modem
JP RCVRDY ;check receive ready
JP SNDRDY ;check send ready
JP SPEED ;get speed value for file transfer time
JP EXTRA1 ;extra for custom routine
JP EXTRA2 ;extra for custom routine
JP EXTRA3 ;extra for custom routine
;
;-----------------------------------------------------------------------
;
; Output character to console
;
CONOUT EQU 0 ; not used
;
;-----------------------------------------------------------------------
;
; Initialize modem
;
; This procedure has been usurped to dynamically detect the type
; of system we are running on and install the *real* jump table
; entries as appropriate.
;
MINIT:
;
; Announce
LD DE,RBC ; RetroBrew Computers
LD C,9 ; BDOS string display function
CALL BDOS ; Do it
;
; Identify BIOS (RomWBW HBIOS or UNA UBIOS)
CALL IDBIO ; 1=HBIOS, 2=UBIOS
LD (BIOID),A ; Save it
DEC A ; Test for HBIOS
JR Z,HINIT ; Do HBIOS setup
DEC A ; Test for UBIOS
JR Z,UINIT ; Do UBIOS setup
;
; Neither UNA nor RomWBW
LD DE,BIOERR ; BIOS error message
LD C,9 ; BDOS string display function
CALL BDOS ; Do it
JP 0 ; Bail out!
;
HINIT:
;
; Display RomWBW notification string
LD DE,HBTAG ; BIOS notification string
LD C,9 ; BDOS string display function
CALL BDOS ; Do it
;
; Get platform id from RomWBW HBIOS and save it
LD B,0F1H ; HBIOS VER function 0xF1
LD C,0 ; Required reserved value
RST 08 ; Do it, L := Platform ID
LD A,L ; Move to A
LD (PLTID),A ; Save it
;
; Get CPU speed from RomWBW HBIOS and save it
LD B,0F8H ; HBIOS SYSGET function 0xF8
LD C,0F0H ; CPUINFO subfunction 0xF0
RST 08 ; Do it, L := CPU speed in MHz
LD A,L ; Move it to A
LD (CPUSPD),A ; Save it
JR MINIT1 ; Continue general initialization
;
UINIT:
;
; Display UNA notification string
LD DE,UBTAG ; BIOS notification string
LD C,9 ; BDOS string display function
CALL BDOS ; Do it
;
; Get CPU speed from UNA and save it
LD C,0F8H ; UNA BIOS Get PHI function
RST 08 ; Returns speed in Hz in DE:HL
LD B,4 ; Divide MHz in DE:HL by 100000H
UINIT1:
SRL D ; ... to get approx CPU speed in
RR E ; ...MHz. Throw away HL, and
DJNZ UINIT1 ; ...right shift DE by 4.
INC E ; Fix up for value truncation
LD A,E ; Put in A
LD (CPUSPD),A ; Save it
JR MINIT1 ; Continue general initialization
;
MINIT1:
; NOTE: PLTID is only set if RomWBW HBIOS is active. This is OK
; because RC2014 is only supported by RomWBW HBIOS at this point.
LD A,(PLTID) ; Get the platform id
CP 7 ; Check for RC2014
JR Z,RCINIT ; Handle RC2014 special
;
; Check for Z180 which implies ASCI serial port
LD DE,00202H ; D := 2, E := 2
MLT DE ; DE := D * E == 4
BIT 2,E ; Bit 2 wil be set if mlt happend
JR Z,MINIT2 ; Not Z180 (ASCI), look for others
LD HL,ASCI_JPTBL ; Point to Z180 (ASCI) jump table
LD DE,ASCI ; ASCI port notification string
JR MINIT3 ; Complete the initialization
;
MINIT2:
; Not a Z180, so assume RBC standard UART serial port
LD HL,UART_JPTBL ; Assume Z80 (UART)
LD DE,UART ; UART port notification string
JR MINIT3 ; Complete the initialization
;
RCINIT:
; RC2014, use HBIOS calls
LD HL,1250 ; Smaller receive loop tiemout scalar
LD (RCVSCL),HL ; ... to compensate for BIOS overhead
LD HL,HBIOS_JPTBL ; HBIOS jump table address
LD DE,COMX ; HBIOS console notification string
JR MINIT3 ; Complete the initialization
;
MINIT3:
PUSH HL ; Save HL
; Display port notification string
LD C,9 ; BDOS string display function
CALL BDOS ; Do it
;
; Newline
LD C,9 ; BDOS string display function
LD DE,CRLF ; Newline
CALL BDOS ; Do it
;
; Copy real vectors into active jump table
POP HL ; Recover HL
LD DE,JPTBL ; Real jump table is destination
LD BC,7 * 3 ; Copy 7 3-byte entries
LDIR ; Do the copy
;
; Return with CPU speed in A
LD A,(CPUSPD) ; A := CPU speed in MHz
LD HL,(RCVSCL) ; HL := receive scalar
RET ; and return
;
; Identify active BIOS. RomWBW HBIOS=1, UNA UBIOS=2, else 0
;
IDBIO:
;
; Check for UNA (UBIOS)
LD A,(0FFFDH) ; fixed location of UNA API vector
CP 0C3H ; jp instruction?
JR NZ,IDBIO1 ; if not, not UNA
LD HL,(0FFFEH) ; get jp address
LD A,(HL) ; get byte at target address
CP 0FDH ; first byte of UNA push ix instruction
JR NZ,IDBIO1 ; if not, not UNA
INC HL ; point to next byte
LD A,(HL) ; get next byte
CP 0E5H ; second byte of UNA push ix instruction
JR NZ,IDBIO1 ; if not, not UNA, check others
LD A,2 ; UNA BIOS id = 2
RET ; and done
;
IDBIO1:
; Check for RomWBW (HBIOS)
LD HL,(0FFFEH) ; HL := HBIOS ident location
LD A,'W' ; First byte of ident
CP (HL) ; Compare
JR NZ,IDBIO2 ; Not HBIOS
INC HL ; Next byte of ident
LD A,~'W' ; Second byte of ident
CP (HL) ; Compare
JR NZ,IDBIO2 ; Not HBIOS
LD A,1 ; HBIOS BIOS id = 1
RET ; and done
;
IDBIO2:
; No idea what this is
XOR A ; Setup return value of 0
RET ; and done
;
;
;
BIOID DB 0 ; BIOS ID, 1=HBIOS, 2=UBIOS
PLTID DB 0 ; Platform ID
CPUSPD DB 10 ; CPU speed in MHz
RCVSCL DW 2800 ; RECV loop timeout scalar
;
RBC DB "RBC, 08-Nov-2017$"
;
UART DB ", UART0$"
ASCI DB ", ASCI0$"
COMX DB ", COM0$"
;
UBTAG DB " [UNA]$"
HBTAG DB " [WBW]$"
;
CRLF DB 13, 10, "$"
;
BIOERR DB 13, 10, 13, 10, "++ Unknown BIOS ++", 13, 10, "$"
;
;-----------------------------------------------------------------------
;
; Uninitialize modem
;
UNINIT:
RET ; not initialized, so no 'UN-INITIALIZE'
;
;-----------------------------------------------------------------------
;
; The following are all dummy routines that are unused because MINIT
; dynamically installs the real jump table.
;
SENDR:
CAROK:
MDIN:
GETCHR:
RCVRDY:
SNDRDY:
SPEED:
EXTRA1:
EXTRA2:
EXTRA3:
RET
;
;=======================================================================
;=======================================================================
;
; Standard RBC Projects 8250-like UART port @ 68H
;
; Will be used for all RBC Z80 systems.
;
;=======================================================================
;=======================================================================
;
; UART port constants
;
U_BASE EQU 68H ; UART base port
U_DATP EQU U_BASE + 0 ; data in port
U_DATO EQU U_BASE + 0 ; data out port
U_CTLP EQU U_BASE + 5 ; control/status port
U_SNDB EQU 20H ; bit to test for send ready
U_SNDR EQU 20H ; value when ready to send
U_RCVB EQU 01H ; bit to test for receive ready
U_RCVR EQU 01H ; value when ready to receive
U_PARE EQU 04H ; bit for parity error
U_OVRE EQU 02H ; bit for overrun error
U_FRME EQU 08H ; bit for framing error
;
; Following jump table is dynamically patched into real jump
; table at program startup. See MINIT above. Note that only a
; subset of the jump table is overlaid (SENDR to SPEED).
;
UART_JPTBL:
JP U_SENDR ; send character (via pop psw)
JP U_CAROK ; test for carrier
JP U_MDIN ; receive data byte
JP U_GETCHR ; get character from modem
JP U_RCVRDY ; check receive ready
JP U_SNDRDY ; check send ready
JP U_SPEED ; get speed value for file transfer time
;
;-----------------------------------------------------------------------
;
; Send character on top of stack
;
U_SENDR:
POP AF ; get character to send from stack
OUT (U_DATO),A ; send to port
RET
;
;-----------------------------------------------------------------------
;
; Test and rep;ort carrier status, Z set if carrier present
;
U_CAROK:
XOR A ; not used, always indicate present
RET
;
;-----------------------------------------------------------------------
;
; Get a character (assume character ready has already been tested)
;
U_MDIN:
U_GETCHR:
IN A,(U_DATP) ; read character from port
RET
;
;-----------------------------------------------------------------------
;
; Test for character ready to receive, Z = ready
; Error code returned in A register
; *** Error code does not seem to be used ***
;
U_RCVRDY:
IN A,(U_CTLP) ; get modem status
;
IF ERRDET
;
; With error detection (slower)
PUSH BC ; save scratch register
PUSH AF ; save full status on stack
AND U_FRME | U_OVRE | U_PARE ; isolate line err bits
LD B,A ; save err status in B
POP AF ; get full status back
AND U_RCVB ; isolate ready bit
CP U_RCVR ; test it (set flags)
LD A,B ; get the error code back
POP BC ; restore scratch register
;
ELSE
;
; No error detection (faster)
AND U_RCVB ; isolate ready bit
CP U_RCVR ; test it (set flags)
LD A,0 ; report no line errors
;
ENDIF
;
RET
;
;-----------------------------------------------------------------------
;
; Test for ready to send a character, Z = ready
;
U_SNDRDY:
IN A,(U_CTLP) ; get status
AND U_SNDB ; isolate transmit ready bit
CP U_SNDR ; test for ready value
RET
;
;-----------------------------------------------------------------------
;
; Report baud rate (index into SPTBL returned in regsiter A)
;
U_SPEED:
LD A,8 ; arbitrarily return 9600 baud
RET
;
;=======================================================================
;=======================================================================
;
; Standard RBC Projects Z180 primary ASCI port
;
; Will be used for all RBC Z180 systems.
;
;=======================================================================
;=======================================================================
;
; ASCI port constants
;
A_DATP EQU 48H ;Z180 TSR - ASCI receive data port
A_DATO EQU 46H ;Z180 TDR - ASCI transmit data port
A_CTLP EQU 44H ;Z180 STAT - ASCI status port
A_CTL2 EQU 40H ;Z180 CNTLA - ASCI control port
A_SNDB EQU 02H ;Z180 STAT:TDRE - xmit data reg empty bit
A_SNDR EQU 02H ;Z180 STAT:TDRE - xmit data reg empty value
A_RCVB EQU 80H ;Z180 STAT:RDRF - rcv data reg full bit
A_RCVR EQU 80H ;Z180 STAT:RDRF - rcv data reg full value
A_PARE EQU 20H ;Z180 STAT:PE - parity error bit
A_OVRE EQU 40H ;Z180 STAT:OVRN - overrun error bit
A_FRME EQU 10H ;Z180 STAT:FE - framing error bit
;
; Following jump table is dynamically patched over initial jump
; table at program startup. See MINIT above. Note that only a
; subset of the jump table is overlaid (SENDR to SPEED).
;
ASCI_JPTBL:
JP A_SENDR ;send character (via pop psw)
JP A_CAROK ;test for carrier
JP A_MDIN ;receive data byte
JP A_GETCHR ;get character from modem
JP A_RCVRDY ;check receive ready
JP A_SNDRDY ;check send ready
JP A_SPEED ;get speed value for file transfer time
;
;-----------------------------------------------------------------------
;
; Send character on top of stack
;
A_SENDR:
POP AF ; get character to send from stack
OUT0 (A_DATO),A ; send to port
RET
;
;-----------------------------------------------------------------------
;
; Test and rep;ort carrier status, Z set if carrier present
;
A_CAROK:
XOR A ; not used, always indicate present
RET
;
;-----------------------------------------------------------------------
;
; Get a character (assume character ready has already been tested)
;
A_MDIN:
A_GETCHR:
IN0 A,(A_DATP) ; read character from port
RET
;
;-----------------------------------------------------------------------
;
; Test for character ready to receive, Z = ready
; Error code returned in A register
; *** Error code does not seem to be used ***
;
A_RCVRDY:
IN0 A,(A_CTLP) ; get modem status
PUSH BC ; save scratch register
PUSH AF ; save full status on stack
AND A_FRME | A_OVRE | A_PARE ; isolate line err bits
LD B,A ; save err status in B
; Z180 ASCI ports will stall if there are errors.
; Error bits are NOT cleared by merely reading
; the status register. Below, bit 3 of ASCI
; control register is written with a zero to
; clear error(s) if needed.
JP Z,A_RCVRDY2 ; if no errs, continue
IN0 A,(A_CTL2) ; get current control register
AND 0F7H ; force err reset bit to zero
OUT0 (A_CTL2),A ; write control register
A_RCVRDY2:
POP AF ; get full status back
AND A_RCVB ; isolate ready bit
CP A_RCVR ; test it (set flags)
LD A,B ; get the error code back
POP BC ; restore scratch register
RET
;
;-----------------------------------------------------------------------
;
; Test for ready to send a character, Z = ready
;
A_SNDRDY:
IN A,(A_CTLP) ; get status
AND A_SNDB ; isolate transmit ready bit
CP A_SNDR ; test for ready value
RET
;
;-----------------------------------------------------------------------
;
; Report baud rate (index into SPTBL returned in regsiter A)
;
A_SPEED:
LD A,8 ; arbitrarily return 9600 baud
RET
;
;=======================================================================
;=======================================================================
;
; HBIOS CONSOLE (COM0:)
;
; Will be used for all RC2014 systems
;
;=======================================================================
;=======================================================================
;
; Following jump table is dynamically patched over initial jump
; table at program startup. See MINIT above. Note that only a
; subset of the jump table is overlaid (SENDR to SPEED).
;
HBIOS_JPTBL:
JP HB_SENDR ;send character (via pop psw)
JP HB_CAROK ;test for carrier
JP HB_MDIN ;receive data byte
JP HB_GETCHR ;get character from modem
JP HB_RCVRDY ;check receive ready
JP HB_SNDRDY ;check send ready
JP HB_SPEED ;get speed value for file transfer time
;
;-----------------------------------------------------------------------
;
; Send character on top of stack
;
HB_SENDR:
POP AF ; get character to send from stack
PUSH BC
PUSH DE
PUSH HL
LD B,01H ; HBIOS OUT function
LD C,0 ; console is unit 0 by fiat
LD E,A ; character to E
RST 08 ; HBIOS call
POP HL
POP DE
POP BC
RET
;
;-----------------------------------------------------------------------
;
; Test and rep;ort carrier status, Z set if carrier present
;
HB_CAROK:
XOR A ; not used, always indicate present
RET
;
;-----------------------------------------------------------------------
;
; Get a character (assume character ready has already been tested)
;
; This routine must NOT block.
;
HB_MDIN:
HB_GETCHR:
PUSH BC
PUSH DE
PUSH HL
LD B,02H ; HBIOS IST function
LD C,0 ; console is unit 0 by fiat
RST 08 ; HBIOS call, A := bytes pending
JR NZ,HB_MDIN1 ; If char(s) waiting, go get it
XOR A ; otherwise, return null
JR HB_MDIN2 ; and done
HB_MDIN1:
LD B,00H ; HBIOS IN function
LD C,0 ; console is unit 0 by fiat
RST 08 ; HBIOS call
LD A,E ; byte received to A
HB_MDIN2:
POP HL
POP DE
POP BC
RET
;
;-----------------------------------------------------------------------
;
; Test for character ready to receive, Z = ready
; Error code returned in A register
; *** Error code does not seem to be used ***
;
HB_RCVRDY:
PUSH BC
PUSH DE
PUSH HL
LD B,02H ; HBIOS IST function
LD C,0 ; console is unit 0 by fiat
RST 08 ; HBIOS call, A := bytes pending
SUB 1 ; CF set IFF zero
RL A ; CF to bit 0 of A
AND 01H ; set Z flag as needed
LD A,0 ; report no line errors
POP HL
POP DE
POP BC
RET
;
;-----------------------------------------------------------------------
;
; Test for ready to send a character, Z = ready
;
HB_SNDRDY:
PUSH BC
PUSH DE
PUSH HL
LD B,03H ; HBIOS OST function
LD C,0 ; console is unit 0 by fiat
RST 08 ; HBIOS call, A := xmit buf bytes avail
SUB 1 ; CF set IFF zero
RL A ; CF to bit 0 of A
AND 01H ; set Z flag as needed
POP HL
POP DE
POP BC
RET
;
;-----------------------------------------------------------------------
;
; Report baud rate (index into SPTBL returned in regsiter A)
;
HB_SPEED:
LD A,8 ; arbitrarily return 9600 baud
RET
;
END