; ================================================================
;   Example source for target 'tap'
;   Tape file for ZX Spectrum and Jupiter ACE
;   Copyright  (c)  Günter Woigk 1994 - 2017
;                   mailto:kio@little-bat.de
; ================================================================


; fill byte is 0x00
; #code has an additional argument: the sync byte for the block.
; The assembler calculates and appends checksum byte to each segment.
; Note: If a segment is appended without an explicite address, then the sync byte and the checksum byte
; of the preceding segment are not counted when calculating the start address of this segment.


#target tap


; sync bytes:
headerflag:     equ 0
dataflag:       equ 0xff


; some Basic tokens:
tCLEAR      equ     $FD             ; token CLEAR
tLOAD       equ     $EF             ; token LOAD
tCODE       equ     $AF             ; token CODE
tPRINT      equ     $F5             ; token PRINT
tRANDOMIZE  equ     $F9             ; token RANDOMIZE
tUSR        equ     $C0             ; token USR


pixels_start    equ 0x4000      ; ZXSP screen pixels
attr_start      equ 0x5800      ; ZXSP screen attributes
printer_buffer  equ 0x5B00      ; ZXSP printer buffer
code_start      equ 24000



; ---------------------------------------------------
;       ram-based, non-initialized variables
;       (note: 0x5B00 is the printer buffer)
;       (note: system variables at 0x5C00 were initialized by Basic)
; ---------------------------------------------------

#data VARIABLES, printer_buffer, 0x100

; define some variables here



; ---------------------------------------------------
;       a Basic Loader:
; ---------------------------------------------------

#code PROG_HEADER,0,17,headerflag
        defb    0                       ; Indicates a Basic program
        defb    "mloader   "            ; the block name, 10 bytes long
        defw    variables_end-0         ; length of block = length of basic program plus variables
        defw    10                      ; line number for auto-start, 0x8000 if none
        defw    program_end-0           ; length of the basic program without variables


#code PROG_DATA,0,*,dataflag

        ; ZX Spectrum Basic tokens

; 10 CLEAR 23999
        defb    0,10                    ; line number
        defb    end10-($+1)             ; line length
        defb    0                       ; statement number
        defb    tCLEAR                  ; token CLEAR
        defm    "23999",$0e0000bf5d00   ; number 23999, ascii & internal format
end10:  defb    $0d                     ; line end marker

; 20 LOAD "" CODE 24000
        defb    0,20                    ; line number
        defb    end20-($+1)             ; line length
        defb    0                       ; statement number
        defb    tLOAD,'"','"',tCODE     ; token LOAD, 2 quotes, token CODE
        defm    "24000",$0e0000c05d00   ; number 24000, ascii & internal format
end20:  defb    $0d                     ; line end marker

; 30 RANDOMIZE USR 24000
        defb    0,30                    ; line number
        defb    end30-($+1)             ; line length
        defb    0                       ; statement number
        defb    tRANDOMIZE,tUSR         ; token RANDOMIZE, token USR
        defm    "24000",$0e0000c05d00   ; number 24000, ascii & internal format
end30:  defb    $0d                     ; line end marker

program_end:

        ; ZX Spectrum Basic variables

variables_end:



; ---------------------------------------------------
;       a machine code block:
; ---------------------------------------------------

#code CODE_HEADER,0,17,headerflag
        defb    3                       ; Indicates binary data
        defb    "mcode     "            ; the block name, 10 bytes long
        defw    code_end-code_start     ; length of data block which follows
        defw    code_start              ; default location for the data
        defw    0                       ; unused


#code CODE_DATA, code_start,*,dataflag

; Z80 assembler code and data

; set print channel to Screen:
        ld      a,2
        call    $1601

; print a message:
        ld      hl,msg
1$      ld      a,(hl)
        and     a
        ret     z
        inc     hl
        rst     2
        jr      1$

msg:    dm      13, "Hello World!", 13, 0

code_end: