[Coco] Re: Disk Basic and 512 byte block floppies.

[John Collyer]

If you want to write a floppy disk driver for Win XP you could add to the
three specific areas below the coco values needed to support real coco
disks.
The floppy disk driver sample from Microsoft driver development kit.

The file flo_data.h located in the directory contains the locations needed.

 "C:\WINDDK\src\storage\fdc\flpydisk\flo_data.h"

If you add the right values then the flpydisk sample could become the
default
floppy driver for Win XP.  Get it tested by Microsoft and they will provide
you with a key.  I think that the standard floppy driver will then
read/write
coco floppies correctly if the right values are added to the file flo_data.h
With the added support you should be able to access the real coco diskettes.
You could add an array and enum to the types all the known coco types you
want supported.


Portions from flo_data.h:

typedef enum _DRIVE_MEDIA_TYPE {
    Drive360Media160,                      // 5.25"  360k  drive;  160k
media

//
// For each drive/media combination, define important constants.
//

typedef struct _DRIVE_MEDIA_CONSTANTS {
    MEDIA_TYPE MediaType;
    UCHAR      StepRateHeadUnloadTime;
    UCHAR      HeadLoadTime;
    UCHAR      MotorOffTime;
    UCHAR      SectorLengthCode;
    USHORT     BytesPerSector;
    UCHAR      SectorsPerTrack;
    UCHAR      ReadWriteGapLength;
    UCHAR      FormatGapLength;
    UCHAR      FormatFillCharacter;
    UCHAR      HeadSettleTime;
    USHORT     MotorSettleTimeRead;
    USHORT     MotorSettleTimeWrite;
    UCHAR      MaximumTrack;
    UCHAR      CylinderShift;
    UCHAR      DataTransferRate;
    UCHAR      NumberOfHeads;
    UCHAR      DataLength;
    UCHAR      MediaByte;
    UCHAR      SkewDelta;
} DRIVE_MEDIA_CONSTANTS, *PDRIVE_MEDIA_CONSTANTS;

//
// The following values were gleaned from many different sources, which
// often disagreed with each other.  Where numbers were in conflict, I
// chose the more conservative or most-often-selected value.
//

DRIVE_MEDIA_CONSTANTS
_DriveMediaConstants[_NUMBER_OF_DRIVE_MEDIA_COMBINATIONS_] =
{
    { F5_160_512,   0xdf, 0x2, 0x25, 0x2, 0x200, 0x08, 0x2a, 0x50, 0xf6,
0xf, 1000, 1000, 0x27, 0, 0x2, 0x1, 0xff, 0xfe, 0 },
    { F5_180_512,   0xdf, 0x2, 0x25, 0x2, 0x200, 0x09, 0x2a, 0x50, 0xf6,
0xf, 1000, 1000, 0x27, 0, 0x2, 0x1, 0xff, 0xfc, 0 },
...
...
...
    { F3_1Pt44_512, 0xd1, 0x2, 0x25, 0x2, 0x200, 0x12, 0x1b, 0x65, 0xf6,
0xf,  500, 1000, 0x4f, 0, 0x0, 0x2, 0xff, 0xf0, 3 },
    { F3_2Pt88_512, 0xa1, 0x2, 0x25, 0x2, 0x200, 0x24, 0x38, 0x53, 0xf6,
0xf,  500, 1000, 0x4f, 0, 0x3, 0x2, 0xff, 0xf0, 6 }
};



John Collyer