; UNMDISK.ASM  BY ERIK A MCBETH DECEMBER 1986
; PLEASE DISTRIBUTE BUT DON'T SELL!!
; ONCE MODIFIED AND ASSEMBLED, UNMDISK.COM WILL "REMOVE" THE MEMORY
; DISK SET UP BY MEM?.COM (OR PLAIN MDISK.COM) SINCE MEM?.COM MODIFIES
; THE BIOS JUMP TABLE.  THIS SHOULD WORK WITH OTHER PROGRAMS THAT MESS
; WITH THIS JUMP TABLE
; WHAT YOU WILL NEED
; 1) ASM.COM (OR CLONE)
; 2) LOAD.COM (OR CLONE)
; 3) TELL.COM
; 4) AN EDITOR   
; 5) TPA.COM (OPTIONAL)
;
; WHAT TO DO
; 1) RUN TELL.COM (GET A HARD COPY USING ^P)
; 2) FIND SECTION OF PROGRAM WITH R????? EQU 0????H AND ENTER VALUES THAT
; TELL.COM GIVES YOU (THE VALUES ARE IN THE ORDER OF TELL, RCONIN IS
; Console Input routine  (waits for char.)
; 3) ASSEMBLE WITH ASM (ASM UNMDISK)
; 4) LOAD WITH LOAD (LOAD UNMDISK)
; 5) RUN NM
; 6) RUN TELL.COM AGAIN AND MAKE SURE THE NUMBERS ARE THE SAME AS THOSE
; PREVIOUS
; 7) RUN MEM?.COM
; 8) WHEN YOU DON'T THE MDISK ANY LONGER, RUN UNMDISK.COM
; 9) USE TPA.COM IF YOU WANT TO CONFIRM THAT UNMDISK IS DOING IT'S JOB
; ERIK A MCBETH
; 22635 IRIS AVE
; TORRANCE, CA 90505

; I'M GOING TO TRY AND REWRITE MEM?.COM SO THAT IT WILL STORE THE ORIGINAL
; BIOS JUMP TABLE AND RESTORE IT WHEN YOU RUN IT AGAIN.


BDOS      EQU  0005H
PSTRING   EQU  09H

; SHOULDN'T NEED TO TOUCH THESE
; THE OFFSET SIMPLY ADDS A ONE TO THE ADDRESS SO THAT WE PUT OUR CORRECT
; JUMP ADDRESS DOWN ON THE MODIFIED ADDRESS AND NOT ON JMP (CODE C3)
OFFSET    EQU  01H
CBOOT     EQU  00H + OFFSET
WBOOT     EQU  03H + OFFSET
CONST     EQU  06H + OFFSET
CONIN     EQU  09H + OFFSET
CONOUT    EQU  0CH + OFFSET
LIST      EQU  0FH + OFFSET
PUNCH     EQU  12H + OFFSET
READER    EQU  15H + OFFSET
HOME      EQU  18H + OFFSET
SELDSK    EQU  1BH + OFFSET
SETTRK    EQU  1EH + OFFSET
SETSEC    EQU  21H + OFFSET
SETDMA    EQU  24H + OFFSET
READ      EQU  27H + OFFSET
WRITE     EQU  2AH + OFFSET
LISTST    EQU  2DH + OFFSET
SECTRAN   EQU  30H + OFFSET

; THESE WILL BE CHANGED USING TELL.COM, IF YOU DON'T CHANGE THESE YOU
; MAY END UP EITHER REFORMATING OR SCREWING SOMETHING UP (NOTHING REALLY
; HORRIBLE)
; BY THE WAY, THESE ARE FOR A KAYPRO 84 WITH TURBOROM AND ZCPR3,ZRDOS


BIOS      EQU  0E200H
RCBOOT    EQU  0E286H
RWBOOT    EQU  0E24EH
RCONST    EQU  0E50CH
RCONIN    EQU  0E50FH
RCONOUT   EQU  0E512H
RLIST     EQU  0E515H
RPUNCH    EQU  0E518H
RREADER   EQU  0E51BH
RHOME     EQU  0E365H
RSELDSK   EQU  0E369H
RSETTRK   EQU  0E36DH
RSETSEC   EQU  0E371H
RSETDMA   EQU  0E375H
RREAD     EQU  0E379H
RWRITE    EQU  0E384H
RLISTST   EQU  0E51EH
RSECTRAN  EQU  0E31AH


          ORG  100H
; IN SIMPLE TERMS, THE FOLLOWING STEPS SIMPLE LOAD IN THE CORRECT
; JUMP ADDRESS AND PLACE IT OVER THE MODIFIED ADDRESS

          LXI   H,RCBOOT  ; PICK UP 0E286H
          SHLD  BIOS+CBOOT ; PUT IT AT 0E201H (0E200H SAYS JMP)

          LXI   H,RWBOOT
          SHLD  BIOS+WBOOT

          LXI   H,RCONST
          SHLD  BIOS+CONST

          LXI   H,RCONIN
          SHLD  BIOS+CONIN

          LXI   H,RCONOUT
          SHLD  BIOS+CONOUT

          LXI   H,RLIST
          SHLD  BIOS+LIST

          LXI   H,RPUNCH
          SHLD  BIOS+PUNCH

          LXI   H,RREADER
          SHLD  BIOS+READER

          LXI   H,RHOME
          SHLD  BIOS+HOME

          LXI  H,RSELDSK
          SHLD  BIOS+SELDSK

          LXI  H,RSETTRK
          SHLD  BIOS+SETTRK

          LXI  H,RSETSEC
          SHLD  BIOS+SETSEC

          LXI  H,RSETDMA
          SHLD  BIOS+SETDMA

          LXI  H,RREAD
          SHLD  BIOS+READ

          LXI  H,RWRITE
          SHLD  BIOS+WRITE

          LXI  H,RLISTST
          SHLD  BIOS+LISTST

          LXI  H,RSECTRAN
          SHLD  BIOS+SECTRAN

          LXI D,UNINMESS  ; OUR MESSAGE
          MVI C,PSTRING   ; WE WANT THE BDOS TO PRINT A STRING
          CALL BDOS       ; PRINT IT
          
          JMP RWBOOT      ; KIND OF SNEAKY, THIS IS THE GENUINE ADDRESS OF
                          ; A WARM BOOT, MIGHT MAKE IT JMP BDOS UNTIL WE GET
                          ; ALL THE NUMBERS RIGHT

          UNINMESS: 
                    DB   '   Bios Jumps Restored$'