DOS Utility to degragment HD

[pearce_jj]

...as an experiment, I wrote a little TSR to make DOS report 6.00 instead of 3.30

;
; VERSION6.ASM
;
; Intercept DOS Int 21h function 30h and return 6.00
;

CODE		SEGMENT BYTE PUBLIC
		ASSUME	CS:CODE, DS:CODE
		ORG	100H

ENTRY:		JMP	INIT
						
HOOK:		CMP	AH, 30H				; function 30h?
		JE	GETVER				; yes, handle locally
			
							; no, chain to DOS
		DB	0EAH				; jmp far
INT21		DD	0				; saved INT21 vector

GETVER:		MOV	AX, 6				; return version 6.00
		IRET

INIT:		MOV	AX, 3521H			; get original INT21 vector
		INT	21H

		MOV	WORD PTR INT21, BX		; and save it
		MOV	WORD PTR INT21 + 2, ES
		
		MOV	AH, 25H				; set new INT21 vector
		MOV	DX, OFFSET HOOK
		INT	21H

		MOV	DX, OFFSET INIT
		INT	27H				; terminate, stay resident

CODE		ENDS
		END	ENTRY

Isn't thee a builtin command to do this since 6.0? DOSVER possibly it was called - and could set the reported version based on the executable running I think

 

[krebizfan]

Isn't thee a builtin command to do this since 6.0? DOSVER possibly it was called - and could set the reported version based on the executable running I think

SETVER which started in DOS 5 and the table of application support could be modified by the user.

 

[Beerhunter]

I don't know if anyone has mentioned this but there was an IBM Internal Use Only program called DVOO (or maybe devoo or similar). I'd try a search for that.

 

[pearce_jj]

Never heard of that - wikipedia seems to suggest it was public though, "The IBM PC DOS operating system that was shipped with the IBM Personal Computers in 1982 had included a Disk Volume Organization Optimizer for defragmenting the 5¼-inch floppy disks that were used by the machines."

 

[Beerhunter]

Never heard of that - wikipedia seems to suggest it was public though, "The IBM PC DOS operating system that was shipped with the IBM Personal Computers in 1982 had included a Disk Volume Organization Optimizer for defragmenting the 5¼-inch floppy disks that were used by the machines."

I find that difficult to believe. (I'll check in the PC DOS manual next time I am in the museum.)

In my time (1983 onward), DVOO was strictly "IBM Internal Use Only" and we only used it to defrag hard files.

 

[Billyray]

I still use Softlogic's Disk Optimizer Ver. 2 for DOS 3.3 Here's a link to a review.