This devhlp is used to read from a file opened with DevHlp_OpenFile.
- ES:DI = point to a SYIReadFile structure
- DL = 081h
- CY=0, AX = 0: read okay
- CY=1, AX = ERROR_BAD_LENGTH: packet is invalid
- CY=1, AX = <>0: other filesystem related errors
; assembler structure SYIReadFile struc length dw 8 ; length of structure (must be 8) buffer dd ? ; 16:16 address of a read buffer size dd ? ; number of bytes to read SYIReadFile ends
Valid at INIT time only. Although the size argument of the data structure implies, I’d recommend to better not read more than 32K at a time. Note that the buffer itself is segmented, so DMA overrun and other effects might apply, depending on the quality of the miniIFS in use.
IMHO, the length of structure should be 10, not 8.