Fields
Sixty-four bytes, with every number big-endian (unlike the 6510's own). The signature, the field order and the checks below match the text of VICE 3.8's cartconv program on this machine, which prints
CRT Version, Name, Hardware ID, Hardware Revision and Mode: exrom, game and refuses a header that is too short. The program itself could not be run here.
| Offset | Size | Field | Meaning | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 16 | Signature | C64 CARTRIDGE followed by three spaces. (VICE's other machines use C128 CARTRIDGE, CBM2 CARTRIDGE, VIC20 CARTRIDGE and PLUS4 CARTRIDGE, padded to 16 the same way.) | ||||||||||||||||||||
16 ($10) | 4 | Header length | normally $00000040. The first CHIP packet starts there; a value below $40 is refused by cartconv (“Illegal header size”), and the explorer then reads from $40. | ||||||||||||||||||||
20 ($14) | 2 | Version | $0100 (1.0) or $0101 (1.1). Version 1.1 is the one with the sub-type byte. | ||||||||||||||||||||
22 ($16) | 2 | Hardware type | which cartridge hardware: Hardware types. A type outside the table gives cartconv “Unknown CRT ID”. | ||||||||||||||||||||
24 ($18)25 ( $19) | 1 1 | EXROM, GAME | the level of the two cartridge-port lines at start-up: 0 pulls the line low (active), 1 leaves it high. The pair chooses the memory map:
| ||||||||||||||||||||
26 ($1A)27-31 | 1 5 | Sub-type (hardware revision), reserved | the hardware revision or variant of the type (cartconv's Hardware Revision), used from version 1.1; the five bytes after it are reserved | ||||||||||||||||||||
32 ($20) | 32 | Name | the cartridge's name as text, padded with zero bytes |
The CHIP packets follow at the header length, normally offset 64.
Not described
Unknown
- Reference: what the sub-type means for each hardware type; the explorer shows the number only.
- Reference: whether the header length is ever above
$40in real files; the explorer shows the extra bytes as a header extension.