Block diagram
TAP files are used by emulators of ZX Spectrum computer (released in 1982 by Sinclair Research). TAP file stores blocks of data as if they are written to magnetic tape, which was used as primary media for ZX Spectrum. Contents of this file can be viewed as a very simple linear filesystem, storing named files with some basic metainformation prepended as a header.
This page hosts a formal specification of ZX Spectrum tape file using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
meta:
id: zx_spectrum_tap
title: ZX Spectrum tape file
file-extension: tap
xref:
justsolve: TAP_(ZX_Spectrum)
pronom: fmt/801
wikidata: Q34748140
license: CC0-1.0
endian: le
doc: |
TAP files are used by emulators of ZX Spectrum computer (released in
1982 by Sinclair Research). TAP file stores blocks of data as if
they are written to magnetic tape, which was used as primary media
for ZX Spectrum. Contents of this file can be viewed as a very
simple linear filesystem, storing named files with some basic
metainformation prepended as a header.
doc-ref: https://sinclair.wiki.zxnet.co.uk/wiki/TAP_format
seq:
- id: blocks
type: block
repeat: eos
enums:
flag_enum:
0x00: header
0xFF: data
header_type_enum:
0: program
1: num_array
2: char_array
3: bytes
types:
block:
seq:
- id: len_block
type: u2
- id: flag
type: u1
enum: flag_enum
- id: header
type: header
if: len_block == 0x13 and flag == flag_enum::header
- id: data
size: header.len_data + 4
if: len_block == 0x13
- id: headerless_data
size: len_block - 1
if: flag == flag_enum::data
header:
seq:
- id: header_type
type: u1
enum: header_type_enum
- id: filename
size: 10
pad-right: 0x20
- id: len_data
type: u2
- id: params
type:
switch-on: header_type
cases:
'header_type_enum::program': program_params
'header_type_enum::num_array': array_params
'header_type_enum::char_array': array_params
'header_type_enum::bytes': bytes_params
- id: checksum
type: u1
doc: Bitwise XOR of all bytes including the flag byte
program_params:
seq:
- id: autostart_line
type: u2
- id: len_program
type: u2
array_params:
seq:
- id: reserved
type: u1
- id: var_name
type: u1
doc: Variable name (1..26 meaning A$..Z$ +192)
- id: reserved1
contents: [0x00, 0x80]
bytes_params:
seq:
- id: start_address
type: u2
- id: reserved
size: 2