;WRITTEN BY RUSSELL BUSHNELL 4/28/88
;VERSION 1.0

;
;
;SMALL XIOS - ALLOWS A LARGER XIOS TO EXIST IN
;NON-COMMON BANKED MEMORY(16K ALLOWED FOR RESIDENT MPM).
;
         ORG 0000H;
         PDISP   EQU $-3;SET IN REAL BIOS
                        ;USE THE VALUE OF XIOS.SPR (MPMLDR)
         XDOS    EQU PDISP-3;
         RXIOS1  EQU 0BFFFH - 0FH;LOCATION OF THE REAL BIOS1(ORG)
         RXIOS2  EQU 00000H;
         RXIOS3  EQU 00000H;
         RXIOS4  EQU 00000H;
         RXIOS5  EQU 00000H;
         BNKPRT  EQU 040H;
         XIOSBNK EQU 001H;
         CDISK   EQU 4;
;
         JMP COLDSTART;FROM COLD START LOADER
         JMP WARMSTART;FROM WARM BOOT
         JMP CONSTD;
         JMP CONIND;
         JMP CONOTD;
         JMP LIST;
         JMP RTNEMPTY;
         JMP RTNEMPTY;
         JMP HOME;
         JMP SELDSK;
         JMP SETTRK;
         JMP SETSEC;
         JMP SETDMA;
         JMP READ;
         JMP WRITE;
         JMP POLLPT;
         JMP SECTRAN;
         JMP SELMEMORY;EXTENDED I/O HERE DOWN(MPM)!
         JMP POLLDEVICE;
         JMP STARTCLOCK;
         JMP STOPCLOCK;
         JMP EXITREGION;
         JMP MAXCONSOLE;
         JMP SYSTEMINIT;
         JMP IDLE;


;
;
;
COLDSTART:
WARMSTART:
         MVI C,0;
         JMP XDOS;
;
CONSTD:
         CALL SETBNK;ENABLE BANK WERE XIOS IS.
         CALL RXIOS1 + 6;CALL THE REAL BIOS.
         CALL RTNBANK;RESTORE CALLING BANK.
         RET;
;
CONIND:
         CALL SETBNK;
         CALL RXIOS1 + 9;
         CALL RTNBANK;
         RET;
;
CONOTD:
         CALL SETBNK;
         CALL RXIOS1 + 12;
         CALL RTNBANK;
         RET;
;
LIST:
         CALL SETBNK;
         CALL RXIOS1 + 15;
         CALL RTNBANK;
         RET;
;
RTNEMPTY:
         CALL SETBNK;
         CALL RXIOS1 + 18;
         CALL RTNBANK;
         RET;
;
HOME:
         CALL SETBNK;
         CALL RXIOS1 + 24;
         CALL RTNBANK;
         RET;
;
SELDSK:
         CALL SETBNK;
         CALL RXIOS1 + 27;
         CALL RTNBANK;
         RET;
;
SETTRK:
         CALL SETBNK;
         CALL RXIOS1 + 30;
         CALL RTNBANK;
         RET;
;
SETSEC:
         CALL SETBNK;
         CALL RXIOS1 + 33;
         CALL RTNBANK;
         RET;
;
SETDMA:
         CALL SETBNK;
         CALL RXIOS1 + 36;
         CALL RTNBANK;
         RET;
;
READ:
         CALL SETBNK;
         CALL RXIOS1 + 39;
         CALL RTNBANK;
         RET;
;
WRITE:
         CALL SETBNK;
         CALL RXIOS1 + 42;
         CALL RTNBANK;
         RET;
;
POLLPT:
         CALL SETBNK;
         CALL RXIOS1 + 45;
         CALL RTNBANK;
         RET;
;
SECTRAN:
         CALL SETBNK;
         CALL RXIOS1 + 48;
         CALL RTNBANK;
         RET;
;
SELMEMORY:
         LXI H,3;
         DAD B;
         MOV A,M;
         STA CURBNK;
         OUT BNKPRT;
         RET;
CURBNK:  DB 01H;
;
POLLDEVICE:
         CALL SETBNK;
         CALL RXIOS1 + 54;
         CALL RTNBANK;
         RET;
;
STARTCLOCK:
         CALL SETBNK;
         CALL RXIOS1 + 57;
         CALL RTNBANK;
         RET;
;
STOPCLOCK:
         CALL SETBNK;
         CALL RXIOS1 + 60;
         CALL RTNBANK;
         RET;
;
EXITREGION:
         CALL SETBNK;
         CALL RXIOS1 + 63;
         CALL RTNBANK;
         RET;
;
MAXCONSOLE:
         CALL SETBNK;
         CALL RXIOS1 + 66;
         CALL RTNBANK;
         RET;
;
SYSTEMINIT:
         DI;
         MVI A, XIOSBNK;
         STA CURBNK;
         SHLD SVDJT;
         MOV L,C;
         MVI H,0;
         DAD H;
         DAD H;
         DAD H;
         SHLD SVDBPA;
;
         MVI A,10H;
         CALL STMVTR;
         MVI A,08H;
         CALL STMVTR;
         MVI A,04H;
         CALL STMVTR;
         MVI A,02H;
         CALL STMVTR;
         MVI A,01H;
         CALL STMVTR;
;
STMVTR:
         OUT 040H;
         CALL BOOT2;
         MVI A,0C3H;
         STA 0;
         LHLD SVDJT;
         SHLD 1;
         MVI A,0C3H;
         STA 0020H;
         LXI H,INTLHND;
         SHLD 0021H;
         RET;
;
BOOT2:
         XRA A;CLEAR SCRATCH AREA
         STA CDISK;
         MVI C,ENDZ-STARTZ;GET LENGTH OF ZERO AREA
         LXI H,STARTZ;GET SCRATCH ADDRESS
BOOTL:   MOV M,A;PUT ZERO IN MEMORY
         INX H;INC. POINTER
         DCR C;DECREMENT
         JNZ BOOTL;LOOP TILL DONE
         MVI M,LLIMIT;SET LINE LIMIT
         INX H;POINT TO LATCH BYTE
         MVI M,0;SET LATCH CODE = 0
GOCPM:
;
         ;SET JUMPS INTO CP/M IN LOWER MEMORY
;
         LXI H,80H;SET DEFAULT DMA ADDRESS
         SHLD DMAADD;
         RET;
;
IDLE:
         CALL SETBNK;
         CALL RXIOS1 + 72;
         CALL RTNBANK;
         RET;
;
SETBNK:
               ;ENABLES NON-COMMON XIOS BANK
         PUSH A;
         MVI A, XIOSBNK;
         OUT BNKPRT;
         POP A;
         RET;
;
RTNBANK:
                   ;RESTORES XIOS CALLING BANK
         PUSH A;
         LDA CURBNK;
         OUT BNKPRT;
         POP A;
         RET;
;
END;THATS ALL