; B5MH-3.INS - BYE5 insert for Morrow MD5, MD11, MD16, MD34 - 10/10/85
;
; Z80 SIO
;
; This is an insert, not an overlay
;
; This insert adapts the Morrow computers using hard disk and CP/M+
; with banked memory to BYE5.
;
;
;= = = = = = = = = = = = = = = = = =
;
; 10/10/85 Reorganized and simplified. - Ed Meyer
; B5MH-3
;
; 08/25/85 Fixed BUG in the Morrow BIOS INTER-BANK routine.
; B5MH-2 - Paul Bartholomew
;
; 08/17/85 Updated for compatibility with BYE501.
; B5MH-1 - George Peace
;
;= = = = = = = = = = = = = = = = = =
;
;
; To get this to work correctly with a Morrow MD-HD, you must use the
; following cable configuration:
;
; Modem End Morrow MD-HD End
; ========= ================
; GND 1 <--------> 1 GND - ground
; TD 2 --------> 3 RD - receive data
; RD 3 <-------- 2 TD - transmit data
; SG 7 <--------> 7 SG - signal ground
; CD 8 --------> 4 CD - carrier detect
; DTR 20 <-------- 5 DTR - data terminal ready
;
;
; Depending on the setting of the jumpers inside your computer, pins 2
; and 3 may or may not need to be crossed.
;
; MAKE SURE THE JUMPERS INSIDE THE MORROW ARE SET TO FACTORY SETTINGS.
; (See Appendix D, figures D-5 and D-6 of the MD-11 users guide)
;
; NOTE: The CD (Carrier Detect) line is connected the Morrow pin 4 (RTS
; on most computers, while usually pin 8 is carrier detect.)
;
;-----------------------------------------------------------------------
;
;
; Set ONE of the following to YES, the other to NO
;
PMPORT EQU NO ; Yes, using "Printer/Modem" port
AUXPORT EQU YES ; Yes, using "Auxilliary" port
;
PORT EQU 060H ; Port for local console output
CONST EQU PORT+1 ; Local console status
;
;
IF PMPORT
BPORT EQU 062H
BAUDS EQU 051H
MODEW EQU 07EH
ENDIF ; PMPORT
IF AUXPORT
BPORT EQU 070H
BAUDS EQU 050H
MODEW EQU 03EH
ENDIF ; AUXPORT
;
;
; The following define the port addresses to use.
;
DPORT EQU BPORT ; Data port
MDCTL1 EQU BPORT+1 ; Status/control port
BRPORT EQU 053H
;
;
; The following are MDCTL1 status masks
;
MDRCV EQU 1 ; Data available
MDSND EQU 4 ; Transmit buffer empty
DCD EQU 8 ; Data carrier detect
;
;-----------------------------------------------------------------------
;
;
; See if we still have a carrier - if not, return with the zero flag set
;
MDCARCK:MVI A,10H ; Reset status
OUT MDCTL1
IN MDCTL1 ; Get status
ANI DCD ; Check for data carrier
RET ; Return
;.....
;
;
; Disconnect and wait for an incoming call
;
MDINIT: MVI A,18H ; Reset channel
OUT MDCTL1
MVI A,4 ; Setup to write register 4
OUT MDCTL1
MVI A,44H ; No parity, 1 stop, 16x
OUT MDCTL1
MVI A,1 ; Setup to write register 1
OUT MDCTL1
MVI A,0
OUT MDCTL1
MVI A,5 ; Setup to write register 5
OUT MDCTL1
MVI A,0 ; DTR, RTS both off
OUT MDCTL1
PUSH B ; Save in case it's being used elsewhere
MVI B,20 ; 2 second delay
;
OFFTI: CALL DELAY ; 0.1 second delay
DCR B
JNZ OFFTI ; Keep looping until finished
POP B ; Restore bc
MVI A,3 ; Setup to write register 3
OUT MDCTL1
MVI A,0C1H ; 8 bits, enable receive
OUT MDCTL1
MVI A,5 ; Setup to write register 5
OUT MDCTL1
MVI A,0EAH ; DTR, RTS, TX on, 8 bits
OUT MDCTL1
IF IMODEM ; If using intelligent modem
CALL IMINIT ; Go initialize modem now
ENDIF ; IMODEM
;
RET ; Return
;.....
;
;
; Input a character from the modem port
;
MDINP:
IN DPORT ; Get character
RET ; Return
;.....
;
;
; Check the status to see if a character is available. If not, return
; with the zero flag set. If yes, use 0FFH to clear the flag.
;
MDINST:
IN MDCTL1 ; Get status
ANI MDRCV ; Got a character?
RZ ; Return if none
ORI 0FFH ; Otherwise, set the proper flag
RET ; And return
;.....
;
;
; Send a character to the modem
;
MDOUTP: OUT DPORT ; Send it
RET ; Return
;.....
;
;
; See if the output is ready for another character
;
MDOUTST:
IN MDCTL1
ANI MDSND ; Mask it
RET ; Return
;.....
;
;
; Reinitialize the modem and hang up the phone by dropping DTR and
; leaving it inactive.
;
MDQUIT: IF IMODEM ; If using an intelligent modem
CALL IMQUIT ; Tell it to shut down
ENDIF ; IMODEM
;
;
; Called by the main program after caller types BYE.
;
MDSTOP: MVI A,5 ; Setup to write register 5
OUT MDCTL1
MVI A,0 ; Clear DTR, RTS causing shutdown
OUT MDCTL1
RET
;.....
;
;
; The following routine sets the baudrate. BYE5 asks for the maximum
; speed you have available.
;
SETINV: MVI A,0FFH
ORA A ; Make sure the zero flag is set
RET
;.....
;
;
SET300: LXI H,BD300
JMP SETBAUD
;.....
;
;
SET1200:LXI H,BD1200
JMP SETBAUD
;.....
;
;
SET2400:LXI H,BD2400
JMP SETBAUD
;.....
;
;
SETBAUD:MVI A,MODEW
OUT BRPORT
MOV A,M
OUT BAUDS
INX H
MOV A,M
OUT BAUDS
XRA A ; Say rate is ok
RET ; Return
;.....
;
;
; The following are baud rates for BPORT -- they will have to be changed
; for your particular CTC.
;
BD300: DW 832
BD1200:DW 208
BD2400:DW 104
BD9600:DW 26
;.....
;
;
;Find address of INTER-BANK BUG in Morrow's BIOS
;
FINDBUG:LDA FNDBUG ; See if we already found the address
ORA A
JZ FBUG0 ; No, go find it
LHLD BUGADR ; Yes, return with address
RET
;.....
;
;
FBUG0: LHLD 1
INX H
MOV E,M
INX H
MOV D,M
XCHG ; Hl points to warm boot code
;
;
; The warm boot in common memory is as follows:
;
; loc opcodes mneumonics
; ---- ------- --------------------
; xxxx 21 yyyy LD HL,BNK-WBOOT ;WARM BOOT code in SYSTEM bank
; xxxx 18 zz JR INTER-BANK
;
; We will find the address of INTER-BANK and modify it to fix the BUG.
;
; The INTER-BANK code in COMMON memory is as follows:
;
; loc opcodes mneumonics
; ---- ------- --------------------
; xxxx 3A yyyy LD A,(SYSMTE-BANK-BITS)
; xxxx CB 47 BIT 0,A ;Should be BIT 1,A (CB 4F)
;
;
;
FBUG1: MOV A,M
CPI 18H ; Look for JR to INTER-BANK
JZ FBUG2
INX H
JMP FBUG1
;
FBUG2: INX H
MOV A,M ; Get JR offset
INX H
MOV E,A
MVI D,0
DAD D ; HL now points to INTER-BANK
;
FBUG3: MOV A,M
CPI 0CBH ; Look for bit opcode
JZ FBUG4
INX H
JMP FBUG3
;
FBUG4: INX H
SHLD BUGADR
MVI A,0FFH
STA FNDBUG
RET
;.....
;
;
FNDBUG: DB 0
BUGADR: DW 0
BUGVAL: DB 0
;.....
;
;
; Perform system or hardware dependent PRE-processing. The following
; code will be executed by the PATCH subroutine before the BIOS jump
; table is overwritten. This will allow the BIOS intercept routines to
; operate as early as the initial signon message display.
;
MDPREP: CALL FINDBUG ; Get address of BIOS bug
MOV A,M
STA BUGVAL ; Save old value
MVI M,04FH ; Change the bit 0,A to a bit 1,A
;
;
; OK, the BIOS BUG is now fixed.
;
;
; Replace the NEWJTBL BIOS routing table with our own
;
;
LXI H,JTBLNEW ; Get replacement table address
LXI D,NEWJTBL ; Get address to overwrite
LXI B,JTBLEN ; Get number of bytes to overwrite
DB 0EDH,0B0H ; Move the jump table
;
;
; Move the BIOS intercept routines up to common memory
;
LXI H,STCOMN ; Start of interface routines
LXI D,COMMN ; Address in high memory to load them
LXI B,COMLEN ; Length of common code
DB 0EDH,0B0H ; Move the code to common memory
RET
;.....
;
;
; Perform system or hardware dependent POST-processing. The following
; code will be executed by the EXCPM routine before returning control to
; CP/M Plus when the BYE5 program is terminated.
;
MDPOSP: CALL FINDBUG ; Get address of BIOS bug
LDA BUGVAL ; Get old value
MOV M,A ; Un-fix the BIOS bug (make it a bit 0)
RET
;.....
;
;
; The following code is required for proper operation on the Morrow
; MD-HD. As the MD-HD operates in a banked environment, BIOS calls MAT
; originate in any bank (0 or 1). It is therefore possible that window
; 1 (where BYE5 resides) will not be selected at the time a BIOS call is
; made. As a result, steps must be taken to be sure that the BIOS jump
; table does not direct a BIOS call into bank 1 unless that bank is
; selected. This code is moved up to common memory where it will be
; visible to all banks. For each of the intercepted BIOS calls, it will:
;
; - save the caller's stack pointer
; - save the caller's bank select mask
; - switch to bank 1
; - execute the BYE interface routine and then the
; original BIOS routine as necessary
; - recover the caller's stack pointer
; - reset the bank select mask to that of the caller
; - return control to the caller
;
;
;NOTE: With Morrow MD-HD computers (BIOS <= 2.0), the free common memory
; is from FF48H to FFA9H (97 bytes). Make sure COMLEN is <= 61H!
;
; All other common RAM is used by BIOS for stacks and interrupts.
;
;
COMMN EQU 0FF48H ; Address for unmodified bios <= 2.0
;
SXBIOS EQU 0F885H ; Address of stack for BIOS intercepts
;
PNTSELM EQU 0FE51H+1 ; Pointer to SELMEN JMP +1
;
BNKSTB EQU 41H ; Bank select port
;
STCOMN EQU $
;
WBCOMN EQU COMMN+($-STCOMN) ; Warm boot
CALL SWIN
JMP MBOOT
;.....
;
;
CSCOMN EQU COMMN+($-STCOMN) ; Console status
CALL SWIN
CALL MSTAT
JMP SWOUT
;....
;
;
CICOMN EQU COMMN+($-STCOMN) ; Console input
CALL SWIN
CALL MINPUT
JMP SWOUT
;.....
;
;
COCOMN EQU COMMN+($-STCOMN) ; Console output
CALL SWIN
CALL MOUTPUT
JMP SWOUT
;.....
;
;
SWIN EQU COMMN+($-STCOMN) ; Bank switch in routine
; Destroys register HL,A
POP H ; Get return address
DB 0EDH,073H
DW SXSAVE
LXI SP,SXBIOS ; Load new stack pointer in common
PUSH H
CALL FNDSBB ; HL=address of SYSTEM-BANK-BITS
MOV A,M
RRC ; Bank # in bit 1, move to bit 0
ANI 1 ; A now has the current bank in it
POP H
PUSH PSW ; Save it for return from BIOS
MVI A,1 ; Get bank 1 mask
CALL SELMEM
PUSH H ; Put return address on new stack
RET
;.....
;
;
SWOUT EQU COMMN+($-STCOMN) ; Bank switch out routine
MOV H,A ; Save A reg. (for console input call)
POP PSW ; Retrieve caller's bank selection mask
DB 0EDH,07BH
DW SXSAVE
CALL SELMEM
MOV A,H ; Restore A reg. (for console input call)
RET
;.....
;
;
SELMEM EQU COMMN+($-STCOMN)
PUSH H
LHLD PNTSELM
CALL MYPC
POP H
RET
;.....
;
;
MYPC EQU COMMN+($-STCOMN)
PCHL
;.....
;
;
FNDSBB EQU COMMN+($-STCOMN) ; Point HL to SYSMTE-BANK-BITS
PUSH D
LHLD PNTSELM
INX H
INX H
MOV E,M
INX H
MOV D,M ; DE points to SYSTEM-BANK-BITS
XCHG
POP D
RET
;.....
;
;
SXSAVE EQU COMMN+($-STCOMN)
DS 2 ; Save area for caller's stack pointer
;
COMLEN EQU $-STCOMN ; Length of common memory interface code
;
JTBLNEW:
JMP MCBOOT ; Cold boot
JMP WBCOMN ; Warm boot
JMP CSCOMN ; Modem status test
JMP CICOMN ; Modem input routine
JMP COCOMN ; Modem output routine
;
IF (NOT HARDLOG) AND (NOT PRINTER)
JMP COCOMN ; Modem list device
JMP COCOMN ; Modem punch device
JMP CICOMN ; Modem reader device
ENDIF ; (NOT HARDLOG) AND (NOT PRINTER)
;
JTBLEN EQU $-JTBLNEW
;
; end
;----------------------------------------------------------------------
