INT 2F U - DOS 4.0+ SELECT - DISPLAY FORMAT DISK PROMPT AX = ADC1h Return: AX destroyed??? Note: This function is called by DOS 4.0+ FORMAT utility just as it prompts for a disk to be formatted. It is only issued when the undocumentedInformation about a product which is not publicly available from the manufacturer, and must be determined by reverse-engineering (disassembly, trial-and-error, etc.). Undocumented information tends to change -- often dramatically -- between successive revisions of a product, since the manufacturer has no obligation to maintain compatibility in behavior which is not explicitly stated. /SELECT option was specified and is intercepted by SELECT displaying the prompt. However, the callout is still present in DOS 6.0 at least.