The H8 IDE Controller is a special piggy-back board for the Z80, designed to fit on the modern Z80 CPU boards, that provides an interface to IDE devices, including Compact Flash cards (using a simple adapter).
This implementation supports only one drive, and treats it as a CompactFlash card.
The CF card images are simple blocks of data, of the specified size (capacity). MMS software will initialize/use the "magic sector" data with partitioning and filesystem information. This magic sector is the same format as used for the MMS 77320 or Z67 SASI disks (with different boot code).
fmtsasi.jar may be used to create GIDE images that include the header, for use with the extended cpmtools. This also initializes the boot code for GIDE (different from SASI), as well as the partition tables. This is the preferred method for creating GIDE images.
MMS Software also supports segmentation of large (> 256M) CF cards. Segments are 256M in size, and are denoted in the boot string as 'A' thru 'Z'. Segments cannot be mixed or changed once booted.
In the MMS Monitor ROM, the boot letter for the GIDE is 'X' and the "unit number" is the partition number (only one LUN is supported). To boot partition 0 of the GIDE CF card, using segment A, the boot command is:
SW501 settings for default boot from GIDE are x101xxxx.