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- ;
- ; System-dependent installation overlay for ZMP
- ;
- ; Insert your own code as necessary in this file. Code contained herein
- ; has been written in Z80 code for use with M80. Once assembled,
- ; convert to hex with RELHEX and use MLOAD to overlay it over the main
- ; ZMPX.COM file to produce your very own ZMP.COM.
- ;
- ; Notes on modifying this file:
- ; Hi-Tech C requires that functions do not change either index register
- ; (IX or IY). If your overlay requires either of these to be changed, ensure
- ; they are restored to their original values on return.
- ; Since collecting parameters from C functions can be tricky, only change
- ; the parts marked 'Insert your own code here'. Do NOT modify the jump
- ; table at the start. Do NOT modify the entry/exit sections of each
- ; function. Do NOT pass 'GO'. Do NOT collect $200.
- ; Apart from defining modem functions, this file also defines terminal
- ; characteristics. Most have been set up for ADM-3A (with a few of my own
- ; additions). Modify to suit your own terminal. An inline print routine
- ; is provided for printing strings in the usual way: usage is
- ;
- ; call print
- ; db 'required string',0
- ;
- ; Don't forget to set your clock speed at the clkspd variable.
- ;
- ; If you find your overlay exceeds the maximum size (currently 0400h),
- ; you will have to re-compile the whole thing. Good luck. You might try
- ; informing us if you need to do this: if too many people need to do it, we
- ; haven't allowed enough room.
- ;
- ; Ron Murray 15/8/88
- ;
-
- ;User-set variables:
- clkspd equ 2 ; Processor clock speed in MHz
- mspeed equ 003ch ; Current baud rate: as used by BYE etc
- ; This MUST be the same as Mspeed in
- ; ZMP.H
-
- ;Set the following two equates to the drive and user area which will
- ; contain zmp's .OVR files, .CFG file and .FON file. Set both to zero
- ; to locate them on the drive from which zmp is invoked.
-
- overdrive equ 'A' ; Drive to find overlays on. Range is 'A'-'P'
- overuser equ 0 ; User area to find overlays
-
- userdef equ 0145h ; origin of this overlay: get this value
- ; from the .SYM file produced when ZMP.COM
- ; is linked
- ovsize equ 0400h ; max size of this overlay
-
- .z80 ; use z80 code
- aseg ; absolute
-
- org userdef
-
- esc equ 1bh
- ctrlq equ 11h
- cr equ 0dh
- lf equ 0ah
- bdos equ 5
-
- codebgn equ $
-
- ;Jump table for the overlay: do NOT change this
- jump_tab:
- jp scrnpr ; screen print
- jp mrd ; modem read with timeout
- jp mchin ; get a character from modem
- jp mchout ; send a character to the modem
- jp mordy ; test for tx buffer empty
- jp mirdy ; test for character received
- jp sndbrk ; send break
- jp cursadd ; cursor addressing
- jp cls ; clear screen
- jp invon ; inverse video on
- jp invoff ; inverse video off
- jp hide ; hide cursor
- jp show ; show cursor
- jp savecu ; save cursor position
- jp rescu ; restore cursor position
- jp mint ; service modem interrupt
- jp invec ; initialise interrupt vectors
- jp dinvec ; de-initialise interrupt vectors
- jp mdmerr ; test uart flags for error
- jp dtron ; turn DTR on
- jp dtroff ; turn DTR OFF
- jp init ; initialise uart
- jp wait ; wait seconds
- jp mswait ; wait milliseconds
- jp userin ; user-defined entry routine
- jp userout ; user-defined exit routine
- jp getvars ; get variables
-
- ;Spare jumps for compatibility with future versions
- jp spare ; spares for later use
- jp spare ; spares for later use
- jp spare ; spares for later use
- jp spare ; spares for later use
- jp spare ; spares for later use
-
- ;
- ; Main code starts here
- ;
- ;Screen print function
- scrnpr:
- ; <== Insert your own code here
- call print
- db 'This function not supported.',cr,lf,0
- ; <== End of your own code
- spare:
- ret
-
- ;User-defined entry routine: leave empty if not needed
- userin:
- ret
-
- ;User-defined exit routine: leave empty if not needed
- userout:
- ret
-
-
- ;Get a character from the modem: return in HL
- mchin:
- push bc
- ; <== Insert your own code here
- ld b,0 ; get input character
- call calmod ; in A
- ; <== End of your own code
- ld l,a ; put in HL
- ld h,0
- or a ; set/clear Z
- pop bc
- ret
-
- ;Send a character to the modem
- mchout:
- ld hl,2 ; get the character
- add hl,sp
- ld a,(hl)
- ; <== Insert your own code here
- push bc
- ld b,2 ; output to modem
- call calmod
- pop bc
- ; <== End of your own code
- ret ; done
-
- ;Test for output ready: return TRUE (1) in HL if ok
- mordy:
- ; <== Insert your own code here
- push bc
- ld b,4
- call calmod ; get status reg
- pop bc
- ld e,a ; save for test
- and 010h ; get tx buffer empty flag in A
- ld hl,1 ; assume ready
- jr nz,mordy1
- ld a,e ; ok, not ready. Is carrier there?
- and 020h
- jr nz,mordy1 ; no, fake it so we don't hang
- dec hl ; otherwise say not ready
- mordy1:
- ; <== End of your own code
- ld a,l ; set/clear Z
- or a
- ret
-
- ;Test for character at modem: return TRUE (1) in HL if so
- mirdy:
- ; <== Insert your own code here
- push bc
- ld b,4 ; get status reg
- call calmod
- pop bc
- and 08h ; 6551 bit 3
- ld hl,0 ; assume not ready
- jr z,mirdy1
- inc hl ; otherwise set it
- mirdy1:
- ; <== End of your own code
- ld a,l ; set/clear Z
- or a
- ret
-
- ;Send a break to the modem: leave empty if your system can't do it
- sndbrk:
- ; <== Insert your own code here
- push bc
- ld b,8
- call calmod ; get current ctl reg
- push af ; save it
- or 0ch ; set to send break
- ld b,10
- call calmod
- ; <== End of your own code
- ld hl,300
- call waithlms ; wait 300 mS
-
- ; <== Insert your own code here
- pop af
- ld b,10 ; restore original
- call calmod
- pop bc
- ; <== End of your own code
- ret
-
- ;Test UART flags for error: return TRUE (1) in HL if error
- mdmerr:
- ; <== Insert your own code here
- push bc
- ld b,4
- call calmod ; get status reg
- pop bc
- and 07h ; mask off error bits
- ld hl,0 ; assume not ready
- jr z,mdmer1
- inc hl ; otherwise set it
- mdmer1:
- ; <== End of your own code
- ld a,l ; set/clear Z
- or a
- ; <== End of your own code
- ret
-
- ;Turn DTR ON
- dtron:
- ; <== Insert your own code here
- push bc
- ld b,8 ; get command reg
- call calmod
- and 0f0h
- or 0bh ; set DTR & RTS on
- ld b,10
- call calmod
- pop bc
- ; <== End of your own code
- ret
-
- ;Turn DTR OFF
- dtroff:
- ; <== Insert your own code here
- push bc
- ld b,8 ; get command reg
- call calmod
- and 0f0h ; set DTR and RTS off
- ld b,10
- call calmod
- pop bc
- ; <== End of your own code
- ret
-
- ;Initialise the UART
- init:
- ld hl,2 ; get parameters
- add hl,sp
- ex de,hl
- call getparm ; in HL
- ld (brate),hl ; baud rate
- call getparm
- ld (parity),hl ; parity
- call getparm
- ld (data),hl ; data bits
- call getparm
- ld (stop),hl ; stop bits
- ; <== Insert your own code here
- ; using values below
- push bc
- ld b,12 ; read ctl reg
- call calmod ; to get old baud rate
- and 0fh
- ld e,a ; save in E
- ld a,(data) ; get data bits
- cp 7 ; if 7,
- jr nz,setbits
- set 5,e ; set bit 5
-
- setbits:
- ld a,(stop) ; get stop bits
- cp 2
- jr nz,setbrate ; if 2,
- set 7,e ; set bit 7
-
- setbrate:
- ld a,(brate) ; set baud rate: get index
- ld hl,brval
- ld c,a ; rate to BC
- ld b,0
- add hl,bc
- ld a,(hl) ; get baud rate value
- or a ; invalid if zero
- jr z,setctl
- ld a,e ; ok, remove old one
- and 0f0h
- or (hl) ; add new baud rate
- ld e,a
- ld a,c ; restore id
- ld (mspeed),a ; save for future use: this one's valid
-
- setctl:
- ld a,e ; value to a
- or 010h ; internal b/r gen
- ld b,14
- call calmod ; set it up
- ld a,(parity) ; do parity
- ld e,060h ; assume even
- cp 'E' ; even?
- jr z,setpar ; yes
- ld e,040h ; try odd
- cp 'O'
- jr z,setpar
- ld e,0 ; none
-
- setpar:
- ld a,0bh ; RTS, DTR on
- or e ; add parity
- ld b,10
- call calmod ; set it
- pop bc
- ; <== End of your own code
- ret
-
- brate: ds 2 ; baud rate:
- ; 0 = 110 baud 1 = 300 baud 2 = 450 baud
- ; 3 = 600 baud 4 = 710 baud 5 = 1200 baud
- ; 6 = 2400 baud 7 = 4800 baud 8 = 9600 baud
- ; 9 = 19200 baud 10 = 38400 baud 11 = 57600 baud
- ; 12 = 76800 baud
-
- parity: ds 2 ; parity
- data: ds 2 ; data bits
- stop: ds 2 ; stop bits
-
- ;Values for 6551 control reg for each baud rate: 0 if invalid
- brval:
- db 3,6,0,7,0,8,10,12,14,15,0,0,0
-
- ;My system needs a BIOS call to access the UART. If yours doesn't, you don't
- ; need anything here. Otherwise write your own.
- ;Modify the next instruction to jump to the BIOS routine
- calmod:
- ld hl,(1) ; get BIOS address
- ld l,0
- ld de,036h ; add offset into BIOS jump table
- add hl,de ; add to hl
- ld (calmod+1),hl ; modify the code
- push af ; save af
- ld a,0c3h ; use jp instruction
- ld (calmod),a
- pop af ; restore A
- jr calmod ; and do it
-
- ;****************************************************************************
- ;Video terminal sequences: these are for ADM-3A: Modify as you wish
- ;Cursor addressing:
- cursadd:
- ld hl,2 ; get parameters
- add hl,sp
- ex de,hl
- call getparm ; in HL
- ld (row),hl ; row
- call getparm
- ld (col),hl ; column
- ; <== Insert your own code here
- ; using values in row and col
- call print
- db esc,'=',0 ; ADM-3A leadin
- ld a,(row) ; row first
- add a,' ' ; add offset
- call cout
- ld a,(col) ; sane for column
- add a,' '
- call cout
- ; <== end of your own code
- ret
-
- row: ds 2 ; row
- col: ds 2 ; column
-
-
- ;Clear screen:
- cls:
- call print
- db 01ah,0
- ret
-
- ;Inverse video on:
- invon:
- call print
- db esc,')',0
- ret
-
- ;Inverse video off:
- invoff:
- call print
- db esc,'(',0
- ret
-
- ;Turn off cursor:
- hide:
- call print
- db esc,'z',0
- ret
-
- ;Turn on cursor:
- show:
- call print
- db esc,'v',0
- ret
-
- ;Save cursor position:
- savecu:
- ret
-
- ;Restore cursor position:
- rescu:
- ret
-
- ;****************************************************************************
-
- ;Service modem interrupt:
- mint:
- ret ; my system doesn't need this
-
- ;Initialise interrupt vectors:
- invec:
- ret ; ditto
-
- ;De-initialise interrupt vectors:
- dinvec:
- ret ; ditto
-
- ;****************** End of user-defined code ********************************
-
- ;Modem character test for 100 ms
- mrd:
- push bc ; save bc
- ld bc,100 ; set limit
- mrd1:
- call mirdy ; char at modem?
- jr nz,mrd2 ; yes, exit
- ld hl,1 ; else wait 1ms
- call waithlms
- dec bc ; loop till done
- ld a,b
- or c
- jr nz,mrd1
- ld hl,0 ; none there, result=0
- xor a
- mrd2:
- pop bc
- ret
-
- ; Inline print routine: destroys A and HL
-
- print:
- ex (sp),hl ; get address of string
- ploop:
- ld a,(hl) ; get next
- inc hl ; bump pointer
- or a ; done if zero
- jr z,pdone
- call cout ; else print
- jr ploop ; and loop
- pdone:
- ex (sp),hl ; restore return address
- ret ; and quit
-
- ;
- ;Output a character in A to the console
- ;
- cout:
- push bc ; save regs
- push de
- push hl
- ld e,a ; character to E
- ld c,2
- call bdos ; print it
- pop hl
- pop de
- pop bc
- ret
-
- ;Wait(seconds)
- wait:
- ld hl,2
- add hl,sp
- ex de,hl ; get delay size
- call getparm
- ; fall thru to..
- ;Wait seconds in HL
- waithls:
- push bc ; save bc
- push de ; de
- push ix ; and ix
- ld ix,0 ; then point ix to 0
- ; so we don't upset memory-mapped i/o
-
- ;Calculate values for loop constants. Need to have two loops to avoid
- ; 16-bit overflow with clock speeds above 9 MHz.
-
- outerval equ (clkspd / 10) + 1
- innerval equ (6667 / outerval) * clkspd
-
- wait10:
- ld b,outerval
-
- wait11:
- ld de,innerval
-
- wait12:
- bit 0,(ix) ; time-wasters
- bit 0,(ix)
- bit 0,(ix) ; 20 T-states each
- bit 0,(ix)
- bit 0,(ix)
- bit 0,(ix)
- dec de
- ld a,e
- ld a,d
- or e
- jr nz,wait12 ; 150 T-states per inner loop
- djnz wait11 ; decrement outer loop
- dec hl ; ok, decrement count in hl
- ld a,h
- or l
- jr nz,wait10
- pop ix ; done -- restore ix
- pop de ; de
- pop bc ; and bc
- ret
-
- ;Wait milliseconds
- mswait:
- ld hl,2
- add hl,sp
- ex de,hl ; get delay size
- call getparm
- ; fall thru to..
- ;Wait milliseconds in HL
- waithlms:
- push de
- w1ms0:
- ld de,39 * clkspd
- w1ms1:
- dec de
- ld a,d
- or e
- jr nz,w1ms1
- dec hl
- ld a,h
- or l
- jr nz,w1ms0
- pop de
- ret
-
- ;Get next parameter from (de) into hl
- getparm:
- ex de,hl ; get address into hl
- ld e,(hl) ; get lo
- inc hl
- ld d,(hl) ; then hi
- inc hl ; bump for next
- ex de,hl ; result in hl, address still in de
- ret
-
- ;Get address of user-defined variables
- getvars:
- ld hl,uservars
- ret
-
- uservars:
- dw overdrive ; all integer
- dw overuser
-
- if ($ - codebgn) gt ovsize
- toobig: jp errval ; Overlay too large!
- endif
-
- end