TITLE   'NSGEN V3.4 - WRITE CP/M 2.2 TO NORTH STAR DISK'
;       PAGE    44
;
; These routines copyright (c) 1980, 1981, 1982 by Steve Bogolub,
; 2338 S. Scoville Ave., Berwyn, IL 60402. This software may be
; used freely for non-commercial purposes only, and may not be sold.
;
;************************************************************
;
;  THIS PROGRAM IS SET UP TO PROVIDE THE FUNCTIONS
; OF THE DIGITAL RESEARCH STANDARD CP/M PROGRAM
; 'SYSGEN', BUT FOR A NORTH STAR DOUBLE DENSITY
; VERSION OF CP/M. SINCE THE NORTH STAR HAS 10
; SECTORS PER TRACK, WITH 512 BYTES PER SECTOR
; USING DOUBLE DENSITY, THE STANDARD SYSGEN PROGRAM
; IS WORTHLESS. USING THIS VERSION, THE CCP AND
; BDOS ARE WRITTEN OUT TO CONSECTIVE SECTORS OF
; TRACK ONE, 0-9 INCLUSIVE. ELEVEN 512-BYTE
; SECTORS ARE REQUIRED, SO THE LAST ONE IS
; WRITTEN OUT TO TRACK ZERO, SECTOR THREE. THE
; CCP/BDOS CODE IS ASSUMED TO BE LOADED INTO
; CONTIGUOUS MEMORY LOCATIONS STARTING AT 0980H.
; THE CONTROL CODE FOR THE JADE DOUBLE D FLOPPY
; DISK CONTROLLER IS EXPECTED AT ADDRESS 1F80H,
; EXTENDING FOR 1024 BYTES. THIS CODE IS WRITTEN
; OUT TO TRACK ZERO, SECTORS ONE AND TWO. THE
; NORTH STAR BIOS IS ASSUMED TO RESIDE IN MEMORY
; FROM 2380H TO 2F7FH INCLUSIVE. THE LAST 512 BYTES
; OF BIOS (2D80H - 2F7FH) PERFORM THE FUNCTION
; OF DISK BOOT, AND ARE WRITTEN OUT TO TRACK ZERO,
; SECTOR FOUR, WHERE THE NORTH STAR PROM BOOT
; EXPECTS TO FIND THE SYSTEM BOOT CODE. THE REST
; OF BIOS (1ST 3K, 2380H - 2D7FH) IS WRITTEN OUT
; TO TRACK ZERO, SECTORS 5-9 INCLUSIVE. TRACK
; ZERO, SECTOR ZERO IS RESERVED FOR A LIFEBOAT-
; COMPATIBLE ID AND FUTURE ADDITIONS.
;
;  IN ORDER TO FIND THE RIGHT SECTORS, WE ASSUME
; THAT THERE ARE 40 LOGICAL SECTORS PER TRACK,
; NUMBERED 1-40 INCLUSIVE. IN ORDER TO WRITE AT
; HIGH SPEED, WE ASSUME THAT THERE ARE 4 LOGICAL
; SECTORS PER PHYSICAL SECTOR, AND LOAD THE C-REG
; WITH THE APPROPRIATE DEBLOCKING FLAG BEFORE
; CALLING BIOS TO WRITE A SECTOR. IN ADDITION,
; WE READ OR WRITE EVERY 3RD NORTH STAR SECTOR.
;
        ORG     0100H           ;ORG TO TPA
;
;  BDOS EQUATES
;
BDOS    EQU     0005H           ;BDOS ENTRY ADDRESS
CONIN   EQU     1               ;CONSOLE INPUT
CONOUT  EQU     2               ;CONSOLE OUTPUT
;
CR      EQU     0DH             ;ASCII CR
LF      EQU     0AH             ;ASCII LF
;
;  BIOS OFFSET EQUATES
;
WARMB   EQU     0000H           ;BIOS WARM BOOT VECTOR
BIOS    EQU     WARMB+1         ;PTR TO BIOS VECTOR TABLE
;
SELDSK  EQU     1BH-3           ;SELECT DISK DRIVE
SETTRK  EQU     SELDSK+3        ;SET TRACK NUMBER
SETSEC  EQU     SETTRK+3        ;SET SECTOR NUMBER
SETDMA  EQU     SETSEC+3        ;SET DMA ADDRESS
READ    EQU     SETDMA+3        ;READ SELECTED SECTOR
WRITE   EQU     READ+3          ;WRITE SELECTED SECTOR
;
NDRVS   EQU     2               ;# OF DRIVES WE CAN USE
                                ;(ONLY A: AND B: ARE N*)
;
;  CP/M IMAGE ADDRESS (WHERE CCP LEFT BY MOVCPM)
;
CPMIA   EQU     0980H
;
;  PROGRAM START. SET UP STACK PTR AND GET SOURCE DISK.
;
NSGEN:  LXI     SP,NSGEN        ;SET STACK PTR
        LXI     H,HELLO         ;PRINT OUT SIGNON
        CALL    MSGOT
;
GETSRC: LXI     H,SRCMSG        ;ASK FOR SOURCE DISK LETTER
        CALL    MSGOT
        CALL    CHARIN          ;GET SINGLE CHAR FOLDED
        CPI     CR              ;IS ANSWER <RET>?
        JZ      GETDST          ;SKIP SOURCE GET IF SO
        STA     SRCLET          ;SAVE LETTER IF NOT
        SUI     'A'             ;MAP TO BINARY VALUE FROM 0
        CPI     NDRVS           ;MAKE SURE NOT TOO BIG
        JC      SRCOK           ;PASS IF OK
        LXI     H,BADNAM        ;FLAG ERROR IF NOT
        CALL    MSGOT
        JMP     GETSRC          ; AND TRY AGAIN
;
SRCOK:  CALL    BSEL            ;CALL BIOS TO SELECT DISK
        LXI     H,SRCON         ;PROMPT FOR SOURCE DISK
        CALL    MSGOT
        CALL    CHARIN          ;WAIT FOR <RET>
        CPI     CR
        JNZ     REBOOT          ;REBOOT IF ANYTHING ELSE TYPED
;
;  READ THE SYSTEM FROM THE SPECIFIED DRIVE
;
        XRA     A               ;IF OK, FLAG DISK READ OPS
        STA     DFLAG
        CALL    XFRSYS          ;READ SYSTEM INTO MEMORY
        JNZ     GETSRC          ;IF ABORTED, TRY AGAIN
        LXI     H,FNCDUN        ;FUNCTION DONE
        CALL    MSGOT
;
;  GET THE DESTINATION DISK
;
GETDST: LXI     H,DSTMSG        ;GET DESTINATION NAME
        CALL    MSGOT
        CALL    CHARIN
        CPI     CR              ;SEE IF DONE
        JZ      REBOOT          ;GET OUT IF SO
        STA     DSTLET          ;IF NOT, SAVE DEST LETTER
        SUI     'A'             ;MAKE SURE IN RANGE
        CPI     NDRVS
        JC      DSTOK           ;PASS IF SO
        LXI     H,BADNAM        ;FLAG BAD NAME IF NOT
        CALL    MSGOT
        JMP     GETDST          ; THEN ASK AGAIN
;
DSTOK:  CALL    BSEL            ;CALL BIOS TO SELECT DISK
        LXI     H,DSTON         ;PROMPT FOR SOURCE DISK
        CALL    MSGOT
        CALL    CHARIN          ;WAIT FOR <RET>
        CPI     CR
        JNZ     REBOOT          ;REBOOT IF ANYTHING ELSE TYPED
;
;  WRITE TO THE DESTINATION DISK
;
        MVI     A,1             ;FLAG DISK WRITE
        STA     DFLAG
        CALL    XFRSYS          ;WRITE OUT SYSTEM
        JNZ     GETDST          ;NO MSG IF ABORTED
        LXI     H,FNCDUN        ;INDICATE DONE
        CALL    MSGOT
        JMP     GETDST          ;ASK ABOUT WRITING AGAIN
;
;  HERE WHEN DONE TO SELECT DRIVE A AND REBOOT
;
REBOOT: XRA     A               ;SELECT DRIVE A
        CALL    BSEL
        JMP     WARMB           ; THEN REBOOT CP/M
;
;  SUBROUTINE XFRSYS TRANSFERS THE SYSTEM IMAGE FROM
; OR TO THE SELECTED DISK, BASED ON THE CONTENTS OF
; 'DFLAG'. IF 'DFLAG' CONTAINS ZERO, THE SYSTEM IS
; READ IN. IF 'DFLAG' CONTAINS ONE, THE SYSTEM IS
; WRITTEN OUT. BIOS DISK READ AND WRITE ARE CALLED
; DIRECTLY TO DO I/O. IF AN ERROR IS RETURNED FROM
; BIOS, IT IS REPORTED TO THE OPERATOR, WHO IS GIVEN
; THE OPTION OF IGNORING THE ERROR, OR ABORTING THE
; XFER. IF THE XFER WAS ABORTED, WE RETURN NON-ZERO
; IN ACC. BECAUSE THE HOST BUFFER CONTENTS ARE
; SCRAPPED ON I/O ERROR, WE CANNOT RETRY THE I/O.
; BESIDES, THE BIOS HAS ALREADY RETRIED IT FOR US.
;
XFRSYS: MVI     A,MAXSEC        ;GET # OF CP/M SECTORS TO XFER
        STA     SCOUNT          ; AND SET COUNT TO DO
        LXI     H,SECTBL        ;PT TO SECTOR TABLE
        SHLD    SECPTR          ;INIT THE SECTOR ADDRESS PTR
;
;  GET NEXT SECTOR ADDRESS FROM TABLE, AND SET BIOS PTRS
;
NXTSEC: LHLD    SECPTR          ;GET NEXT SECTOR ADDRESS
        MOV     A,M             ; INTO ACC
        RLC                     ;BRING TRACK BIT INTO POSITION
        ANI     1               ;TRACK IS ZERO OR ONE
        MOV     C,A             ;PUT TRK # IN C FOR BIOS
        CALL    BTRK            ;CALL BIOS TO SET TRACK #
        LHLD    SECPTR          ;GET SECTOR ADDRESS AGAIN
        MOV     A,M
        ANI     7FH             ;STRIP TRACK BIT
        MOV     C,A             ;GET INTO CORRECT REG
        INX     H               ;BOP SECTOR TABLE PTR
        SHLD    SECPTR          ; AND UPDATE
        CALL    BSEC            ;CALL BIOS TO SET SECTOR #
        LHLD    SECPTR          ;GET TABLE PTR AGAIN
        MOV     A,M             ;GET LOGICAL SECTOR #
        RRC                     ;CALC MEM OFFSET HIGH BYTE
        ANI     7FH
        MOV     B,A             ;PUT FINAL VALUE IN BC
        MOV     A,M             ;NOW CALC LOW BYTE
        RRC
        ANI     80H
        MOV     C,A
        INX     H               ;BOP PTR AGAIN
        SHLD    SECPTR
        LXI     H,CPMIA         ;CALC MEM ADDR
        DAD     B
        MOV     B,H             ;NEED IT IN BC
        MOV     C,L
        CALL    BDMA            ;CALL BIOS TO SET DMA ADDR
;
;  TIME TO DO THE SECTOR READ OR WRITE. CHECK DFLAG TO DECIDE.
;
DOIO:   LDA     DFLAG           ;ARE WE READING OR WRITING?
        ORA     A               ;IF ZERO, READING
        JNZ     WRTSEC          ;BRANCH IF WRITING
        CALL    BREAD           ;IF READING, CALL BIOS TO DO IT
        JMP     CHKSEC          ;NOW GO CHECK FOR ERRORS
;
WRTSEC: CALL    BWRITE          ;CALL BIOS TO WRITE SECTOR
;
CHKSEC: ORA     A               ;ERROR IF BIOS RETURNS NON-ZERO
        JZ      XFROK           ;PASS IF I/O OK
;
;  I/O ERROR. ASK OPERATOR FOR A RULING.
;
IOERR:  LXI     H,IOEMSG        ;REPORT ERROR, AND ASK
        CALL    MSGOT           ; WHAT ACTION TO TAKE
        CALL    CHARIN          ;GET REPLY
        CPI     'I'             ;IGNORE THE ERROR?
        JZ      XFROK           ;GO ON IF SO
        SUI     'A'             ;ABORT THE XFER?
        JNZ     IOERR           ;ASK AGAIN IF NEITHER OF THE ABOVE
        INR     A               ;IF ABORT,
        RET                     ; RETURN NON-ZERO TO CALLER
;
;  COUNT OFF LAST SECTOR TO SEE IF DONE
;
XFROK:  LDA     SCOUNT
        DCR     A               ;COUNT OFF LAST SECTOR
        STA     SCOUNT
        JNZ     NXTSEC          ;IF MORE TO DO, GO BACK
        RET                     ; ELSE RET ZERO TO CALLER
;
;
;  BIOS I/O ROUTINES -- DISK SELECT
;
BSEL:   MOV     C,A             ;MOVE DISK # TO BIOS REG
        LXI     D,SELDSK        ;SELECT DISK
        JMP     GOBIOS
;
;  -- SET TRACK
;
BTRK:   LXI     D,SETTRK        ;SET TRACK C
        JMP     GOBIOS
;
;  -- SET SECTOR
;
BSEC:   LXI     D,SETSEC        ;SET SECTOR C
        JMP     GOBIOS
;
;  -- SET DMA ADDRESS
;
BDMA:   LXI     D,SETDMA        ;SET DMA ADDR BC
        JMP     GOBIOS
;
;  -- READ SECTOR
;
BREAD:  LXI     D,READ          ;READ SETUP SECTOR
        JMP     GOBIOS
;
;  -- WRITE SECTOR
;
BWRITE: LXI     D,WRITE         ;WRITE SETUP SECTOR
;
;  SINCE WE KNOW THAT THE NORTH STAR I/O IS BEING
; DEBLOCKED, LOAD C-REG WITH A VALUE OF 2 TO PREVENT
; PRE-READ FOR EVERY SECTOR BUT THE LAST ONE. FOR THAT
; SECTOR, LOAD C-REG WITH A VALUE OF 1 TO FORCE A WRITE
; TO FLUSH THE BIOS DEBLOCKING BUFFER BEFORE WE LEAVE,
; OR A REBOOT MAY LOSE THE LAST PHYSICAL SECTOR WE
; WANTED TO WRITE OUT.
;
        MVI     C,2             ;WRITE TO UNALLOCATED
        LDA     SCOUNT          ;CHECK FOR WRITING TO
        DCR     A               ; LAST SECTOR
        JNZ     GOBIOS          ;JUMP IF NOT
        DCR     C               ;FORCE WRITE IF LAST
;
;  XFER TO BIOS VIA VECTOR WHOSE OFFSET IS IN DE
;
GOBIOS: LHLD    BIOS            ;PT TO BIOS WARM BOOT VECTOR
        DAD     D               ;CALC DESIRED VECTOR ADDR
        PCHL                    ;GO THERE
;
;
;  OUTPUT MESSAGE PT'ED AT BY HL TO CONSOLE. MESSAGE
; IS A STRING OF CHARACTERS TERMINATED BY A ZERO BYTE.
;
MSGOT:  MOV     A,M             ;GET NEXT BYTE
        ORA     A
        RZ                      ;IF NULL, DONE
        PUSH    H               ;IF NOT, SAVE PTR
        MOV     E,A             ;CHAR TO BDOS REG
        MVI     C,CONOUT        ;FUNCTION
        CALL    BDOS            ;GO OUTPUT CHAR
        POP     H               ;RESTORE PTR
        INX     H               ;PT TO NEXT BYTE
        JMP     MSGOT           ;GO BACK FOR MORE
;
;  CONSOLE INPUT CHAR FUNCTION. LOWER CASE IS FOLDED
; TO UPPER ON RETURN.
;
CHARIN: MVI     C,CONIN         ;CONSOLE INPUT FUNCTION
        CALL    BDOS            ;GET CHAR FROM CONSOLE
        CPI     'A'+20H         ;FOLD LOWER CASE
        RC
        CPI     'Z'+20H+1
        RNC
        SUI     20H
        RET
;
;  MESSAGES
;
HELLO:  DB      'NSGEN V3.4',0
SRCMSG: DB      CR,LF,'Enter source drive name (A-','A'+NDRVS-1
        DB      ') or <ret> to skip: ',0
DSTMSG: DB      CR,LF,'Enter destination drive name (A-'
        DB      'A'+NDRVS-1,') or <ret> to reboot: ',0
BADNAM: DB      CR,LF,'Invalid drive name.',0
SRCON:  DB      CR,LF,'Source on '
SRCLET: DB      ' :, then type <ret>: ',0
DSTON:  DB      CR,LF,'Destination on '
DSTLET: DB      ' :, then type <ret>: ',0
FNCDUN: DB      CR,LF,'Function complete.',0
IOEMSG: DB      CR,LF,'Disk I/O error. Type "I" to ignore or'
        DB      ' "A" to abort transfer: ',0
;
;  SECTOR ADDRESS TABLE. EACH ENTRY CONSISTS
; OF TWO BYTES. THE FIRST BYTE REPRESENTS THE
; SECTOR'S DISK LOCATION. IF HIGH BIT IS SET,
; SECTOR IS ON TRACK ONE. IF NOT, SECTOR IS
; ON TRACK ZERO. LOW SEVEN BITS REPRESENT SECTOR
; NUMBER WITHIN TRACK. THE SECOND BYTE OF THE
; ENTRY IS THE LOGICAL SECTOR OFFSET FROM THE
; START OF THE CP/M IMAGE IN MEMORY, WHICH IS
; USED TO CALCULATE THE ACTUAL MEMORY ADDRESS
; OF THAT SECTOR SO THAT I/O CAN BE DONE.
;
;  MAXSEC REPRESENTS THE TOTAL NUMBER OF
; SECTORS IN THE TABLE. REASSEMBLE TO CHANGE
; THE NUMBER OF SECTORS INVOLVED IN A TRANSFER.
;
SECTBL:                         ;SECTOR TABLE
;
                                        ; NORTH STAR TRK, SEC
;
        DB      01+80H,00,02+80H,01,03+80H,02,04+80H,03 ; 1,0
        DB      13+80H,12,14+80H,13,15+80H,14,16+80H,15 ; 1,3
        DB      25+80H,24,26+80H,25,27+80H,26,28+80H,27 ; 1,6
        DB      37+80H,36,38+80H,37,39+80H,38,40+80H,39 ; 1,9
        DB      09+80H,08,10+80H,09,11+80H,10,12+80H,11 ; 1,2
        DB      21+80H,20,22+80H,21,23+80H,22,24+80H,23 ; 1,5
        DB      33+80H,32,34+80H,33,35+80H,34,36+80H,35 ; 1,8
        DB      05+80H,04,06+80H,05,07+80H,06,08+80H,07 ; 1,1
        DB      17+80H,16,18+80H,17,19+80H,18,20+80H,19 ; 1,4
        DB      29+80H,28,30+80H,29,31+80H,30,32+80H,31 ; 1,7
        DB      13+00H,40,14+00H,41,15+00H,42,16+00H,43 ; 0,3
        DB      25+00H,56,26+00H,57,27+00H,58,28+00H,59 ; 0,6
        DB      37+00H,68,38+00H,69,39+00H,70,40+00H,71 ; 0,9
        DB      09+00H,48,10+00H,49,11+00H,50,12+00H,51 ; 0,2
        DB      21+00H,52,22+00H,53,23+00H,54,24+00H,55 ; 0,5
        DB      33+00H,64,34+00H,65,35+00H,66,36+00H,67 ; 0,8
        DB      05+00H,44,06+00H,45,07+00H,46,08+00H,47 ; 0,1
        DB      17+00H,72,18+00H,73,19+00H,74,20+00H,75 ; 0,4
        DB      29+00H,60,30+00H,61,31+00H,62,32+00H,63 ; 0,7
;
MAXSEC  EQU     ($-SECTBL)/2    ;# OF SECTORS IN TABLE
;
;  VARIABLE DATA
;
DFLAG:  DS      1               ;=0, READ SYS. =1, WRITE SYS.
SECPTR: DS      2               ;PTR INTO SECTBL
SCOUNT: DS      1               ;COUNT OF SECTORS LEFT TO XFER
;
        END     NSGEN