Mini-floppy Format Compatibilities

[pbirkel]

Because this topic comes up in all forums I thought that I'd post here to point out this interesting CDC Memorandum from 1979:

https://bitsavers.org/pdf/cdc/discs/floppy/E43-TK-001_Minifloppy_Format_Compatitibilities_19790611.pdf

TOC:
1.0 Introduction
1.1 References
2.0 9408 and SA400 Format Capability and Compatibility Head Styles
2.2 Single Density Soft Sector Formats
2.2.1 Minimum Gap Lengths
2.2.2 LSI Controller Capability (Single Density, Soft Sector)
2.3 Double Density Soft Sector Formats
2.4 Hard Sector Format Constraints
2.5 Single Board Minifloppy Controllers
2.5.1 Intel iSBC 204
2.5.2 SD Sales Versafloppy
2.5.3 Micropolis 1071 Controller
2.5.4 North Star Controller
2.5.5 Wameco FDC-l

APPENDIX A: Single Density and Double Density Formats
A.1 Modified IBM and Shugart Single Density Formats
A.2 ECMA Single Density Formats
A.3 Double Density Formats

APPENDIX B: Minimum Gap Lengths
B.1 Affect of Head Style on Gap Length
B.2 Drive Parameter and Variable Definitions
B.3 Minimum Gap 2 Length
B.3.1 Factors Determining Minimum Gap Length
B.3.2 Minimum Gap 2 Length Equations
B.4 Minimum Gap 3 Length
B.4.1 Factors Determining Minimum Gap Length
B.4.2 Minimum Gap 3 Length Equations
B.5 Minimum Gap 1 and Gap 4
B.6 Hard Sector Formats
B.6.1 Minimum Preamble For Postamble Left Blank
B.6.2 Minimum Postamble For Postamble Left Blank

 

[syzygy]

Thanks for this. I have not digested all of it, but this is the first time that I am seeing some specifics about gap length - I had pretty much given up learning more in that area.