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Adding Support for a modified IBM Sectored Disk Format
The IBM sector configuration files are text files in JSON format. The root object of the JSON should be an array. A single file can have as may format descriptions as desired.
There is an example of a configuration file with 2 definitions in it at the end of this document.
Format Identification
name
String - Required
This is a descriptive name of the format. It is only used for informational purposes.
ex: “name”: “North Star”
settings
String - Required
This name is used by the Fast Imager to remember user preferences related to this format.
ex: “settings”: “525NorthStar_Hard10x256”
export
[String] - Required
An array of disk image format names that can be used to save images of this format. It uses the internal names of formats.
ex: “export”: [“northstar_nsi”]
Media and Geometry
media
String - Required
The physical type of media used.
| Value | Description |
|---|---|
| 5.25 | 5.25“ Floppy Disk |
| 3.5 | 3.5” Floppy Disk |
| 8 | 8“ Floppy Disk |
ex: “media”: “5.25”
encoding
String - Required
Encoding and bitrate used.
| Value | Description |
|---|---|
| fm_250 | FM encoding with 250kbps (4µs cell window) |
| fm_500 | FM encoding with 500kbps (2µs cell window) |
| mfm_250 | MFM encoding with 250kbps (4µs cell window) |
| mfm_500 | MFM encoding with 500kbps (2µs cell window) |
| m2fm_500 | M2FM encoding with 500kbps (2µs cell window) |
ex: “encoding”: “fm_250”
bitOrder
String
Bytes stored on disk are most commonly stored in “most significant bit” order, although some platforms store bytes in “least significant bit” order. This value allows you to specify which order should be used. If no value is provided, then it defaults to msb.
| Value | Description |
|---|---|
| msb | Most significant bit comes first |
| lsb | Least significant bit comes first |
ex: “bitOrder”: “lsb”