                page    ,132

;       IOLITE3.ASM    (revised by cjv 30 apr 90)
;       Works only on a color monitor. Snow code removed.
;       Major change is the inclusion of Disk Letters (physical disk)
;       in the highlighted block, upper right corner.
;       Only color shown is white. (I use a mono VGA monitor.)
;

RETFARPOP       MACRO   X
                DB      0CAh
                DW      X
ENDM

CODE            SEGMENT
ASSUME          CS:CODE, DS:CODE, ES:CODE

GREEN           EQU    070h
                ORG     100h

START:          JMP     INIT                               

CATTRIB         DB      00              ;COLOR CRT CHAR ATTRIB STORAGE
DISKLTR         DB      00              ;Drive letter from int 13
COLOR           DB      00              ;DISKIO IND. CHAR ATTRIB STORAGE
CVIDSEG         DW      0B800h          ;BASE ADDR VID RAM SEG (COLOR)
OLDINT13        DD      00000000        ;ORIGINAL INT 13 VECTOR
CoAuthor        DB      'C. J. Vaisvil, 4/30/90'

NEWINT13:       CMP     DL,02h          ;CALL TO DRIVE # >= 1 (B)?
                JNB     HDISK           ;If its a HD, jump to adjust
                PUSH    AX              ;save AX
                MOV     AH,DL           ; swap DL into AH
                ADD     AH,65           ;add the 1st drive letter to AH
                MOV     CS:[DISKLTR],AH ;store the value
                POP     AX              ;get back to where we were
                MOV     CS:[COLOR],GREEN;FLOPPY (A or B)
                JMP     SHORT COLRSET   ;COLOR IS SET

HDISK:          PUSH    AX              ;save AX
                MOV     AH,DL           ;swap DL into AH
                ADD     AH,-61          ;add the 1st hdrive letter to AH
                MOV     CS:[DISKLTR],AH ;store the value
                POP     AX              ;get back to where we were
                MOV     CS:[COLOR],GREEN;FLOPPY (A or B)
                JMP     SHORT COLRSET   ;COLOR IS SET




COLRSET:        PUSH    AX              ;SAVE STUFF WE'LL BE DIDDLING WITH
                PUSH    DS
                MOV     DS,CS:[CVIDSEG] ;VID MEM SEG B800h
                MOV     AH,CS:[COLOR]   ;COLOR is always white

                CLI                                        
                xchg    ah,ds:[9Fh]     ;XCHG AH with B800:009F (r1,col79atr)
                MOV     CS:[CATTRIB],AH
                PUSH    AX              ;save AX
                MOV     AH,CS:[DISKLTR] ;Grab the disk letter
                XCHG    AH,DS:[09Eh]    ;XCHG AH with the ascii @ r1,col79
                MOV     CS:[DISKLTR],AH ;Save the ASCII that was there
                POP     AX              ;get back to where we were
                STI
                POP     DS                                 
                POP     AX                                 
                PUSHF                                      
                CALL    DWORD PTR CS:OLDINT13   ;IN DEBUG: CS:,CALL FAR [XXXX]
                PUSHF                                      
                PUSH    AX                                 
                PUSH    DS                                 
                MOV     DS,CS:[CVIDSEG]                          
                MOV     AH,CS:[CATTRIB]                          

                CLI                                        
                mov     ds:[9Fh],ah             ;MOV AH into B800:009F
                PUSH    AX                      ;Save AX
                MOV     AH,CS:[DISKLTR]         ;get what ascii was there
                mov     ds:[09Eh],AH            ;and put it back
                POP     AX                      ;Get back to where we were
                sti
                POP     DS                                 
                POP     AX                                 
                POPF                                       
                RETFARPOP       2                               

INIT:           PUSH    ES              
                SUB     AX,AX                              
                MOV     ES,AX                              
                MOV     AX,3513h                            
                INT     21h                                 
                MOV     WORD PTR [OLDINT13],BX                          
                MOV     WORD PTR [OLDINT13]+2,ES                          
                LEA     DX,[NEWINT13]                          
                MOV     AX,2513h                            
                INT     21h                                 
                POP     ES                                 
                MOV     DX,OFFSET INIT                       
                INT     27h

CODE            ENDS

                END     START
