File formats¶

Cahute aims at handling all file formats surrounding CASIO calculators, either defined by CASIO themselves or by software made by the community.

Note that there are several ways of exploring file formats by CASIO, depending on what your entrypoint is. The sections in this document

By format¶

The file formats described by topic are the following:

By CASIO container subtype¶

Multiple file formats by CASIO use what has been named a “standard header” by the community. Said header is 32 (0x20) bytes long, and is obfuscated by using bitwise NOT.

The format of this header is the following:

Offset	Size	Field name	Description	Values
0 (0x00)	14 B	File Type (FT)	Type of the file.	See the subsections below.
14 (0x0E)	1 B	Control 1 (C1)	First control byte.	Should be set to `(FS + 0x41) & 0xFF`.
15 (0x0F)	1 B	Reserved		Should be set to `\0`.
16 (0x10)	4 B	File Size (FS)		Big endian 32-bit integer.
20 (0x14)	1 B	Control 2 (C2)	Second control byte.	Should be set to `(FS + 0xB8) & 0xFF`.
21 (0x15)	7 B	Reserved		Should be set to `\0`.
28 (0x1C)	2 B	Obfuscation Options
30 (0x1E)	2 B	Object Count (OC)		Big endian 16-bit integer.

Some subtypes, mostly those for fx-CP and fx-CG models, have a “standard subheader”, which has the following format:

Offset

Size

Field name

Description

Values

0 (0x00)

4 B

Checksum (CS)

Big endian 32-bit integer.

4 (0x04)

1 B

File type (FT)

5 (0x05)

1 B

Target platform (FP)

Value set according to the targeted platform:

Value	Description
`0x00`	fx-CP.
`0x01`	fx-CG (Prizm).

6 (0x06)

4 B

Reserved.

Set to \0.

10 (0x0A)

4 B

Data Size (DS)

Big endian 32-bit integer.

14 (0x0E)

4 B

Control value (C3)

Big endian 32-bit integer.

This should be set depending on the platform to:

For the fx-CP, FS - 0x1000 - 4.
For the fx-CG, FS - 0x7000 - 4.

18 (0x12)

4 B

Reserved.

Set to \0.

22 (0x16)

4 B

Message Zone Size (MZS)

Big endian 32-bit integer.

Unreliable, may and should be set to 0.

26 (0x1A)

6 B

Targeted Add-in Platform (AP)

For C1A, should be set to GY437.

32 (0x20)

28 B

Title (T)

Title or language name.

60 (0x3C)

4 B

File Size (FS)

Big endian 32-bit integer.

64 (0x40)

11 B

Internal Add-in Name (IN)

75 (0x4B)

192 B

Language Labels

8 times a 24 bytes long string.

267 (0x10B)

1 B

e-Activity strip flag (EAS)

Available values are the following:

Value	Description
`0x00`	The e-Activity can’t be used.
`0x01`	The e-Activity can be used.

268 (0x10C)

4 B

Reserved

Set to \0.

272 (0x110)

10 B

Add-in version.

282 (0x11A)

2 B

Reserved.

Set to \0.

284 (0x11C)

14 B

Timestamp

YYYY.MMDD.HHmm-formatted date.

Known types for this container format are the following:

FT (StandardHeader)	FT (StandardSubheader)	Type
`CASIO\0\0\0c2p\0\0\0`	N/A	fx-CP picture
`Ly755 \x2C\0\x01\0\x01\0`	`0x02`	fx-CG f-key files
`Ly755 \x2C\0\x01\0\x01\0`	`0x04`	fx-CG language files
`USBPower\x12\0\x10\0\x10\0`	N/A	fx-9860G language files
`USBPower\x2C\0\x01\0\x01\0`	`0x01`	fx-CG add-ins
`USBPower\x31\0\x10\0\x10\0`	N/A	Main memory archives (fx-CP)
`USBPower\x49\0\x10\0\x10\0`	N/A	e-Activity files
`USBPower\x62\0\x10\0\x10\0`	N/A	Main memory archives (fx-9860G)
`USBPower\x75\0\x10\0\x10\0`	N/A	Main memory archives (fx-CG)
`USBPower\x7D\0\x10\0\x10\0`	N/A	fx-CG picture
`USBPower\xF3\0\x10\0\x10\0`	N/A	fx-9860G add-ins

Todo

Document the \xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF case, in which we need to use the extension instead of the format within the file.

By extension¶

The file formats described by extension are the following:

Extension	Description
`.C2P`	fx-CP picture
`.CAS`	CASIOLINK archives
`.CASRC`	casrc configuration file
`.CAT`	Catalog files (CAT)
`.CTF`	Calculator Text Format (CTF)
`.FXP`	FX Program (FXP)
`.G1A`	fx-9860G add-ins
`.G1E`	e-Activity files
`.G1L`	fx-9860G language files
`.G1M`	Main memory archives
`.G2R`	Main memory archives
`.G3A`	fx-CG add-ins
`.G3L`	fx-CG language files
`.G3M`	Main memory archives
`.G3P`	fx-CG picture
`.GRC`	GraphCard file format