; ***************************************************************************
; Load a machine code program using the TAP format
;
; Author: Peter Mount, Area51.dev & Contributors
; URL: https://area51.dev/sinclair/asm/loaders/tap/
; ***************************************************************************

; 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 explicit 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

; Include Spectrum headers from http://localhost:1313/sinclair/spectrum/reference/include/zasm/headers/
#include "headers.z80"

; ***************************************************************************
; Header block containing the block name and the size of the BASIC program
; ***************************************************************************

#code PROG_HEADER,0,17,0
        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

; ***************************************************************************
; Data block containing a simple BASIC program:
;
; 10 CLEAR 23999            ; Set end of Basic memory
; 20 LOAD "" CODE 24000     ; Load next file to the free memory
; 30 RANDOMIZE USR 24000    ; Execute the loaded code
;
; This will when run mark memory from 24000 (0x5DC0) to be unavailable to
; BASIC and everything above that point is then usable by the machine code
; program who's entry point is address 24000 (0x5DC0).
; ***************************************************************************

#code PROG_DATA,0,*,0xff

                                            ; 10 CLEAR 23999
        defb    0,10                        ; line number
        defb    end10-($+1)                 ; line length
        defb    0                           ; statement number
        defb    BAS_CLEAR                   ; 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    BAS_LOAD,'"','"',BAS_CODE   ; 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    BAS_RANDOMIZE, BAS_USR      ; 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: