; TODO LIST ; - HARDWARE INTERRUPT SYSTEM FUNCTION THING ; - LONG TERM BEEPER, ADD KEYDOWN NOISE ; - KEYBOARD REPEAT ; - GET TAPE DRIVE WORKING ; - SERIAL PORT! ; - ADD 8253 ; - ADD 2ND 8251 ; - ADD RS232 CONVERTER (?) ; - WIRE UP REST OF KEYBOARD LEDS ; - WIRE UP MODIFIER KEYS ; - REWRITE INKEY TO ACCOUNT FOR MODIFIERS ; - MOVE USER RAM TO 0X1000 AND UPGRADE ROM TO 32K ; - ; ---- MEMORY SPACE ---- Stack = 0x2D5F ; and down ScreenBuff = 0x2D60 ; thru to 0x2DFF Vectors = 0x2E00 ; thru to 0x2EFF VECT_H = 0x2E Scratch = 0x2F80 ; 0x2F00 thru 0x2FFF with 0x2FFF (127) being the magic interrupt feedback address ; nothing = -128 SpaceChar_OFF = 0 RWMode_OFF = 1 NibHigh_OFF = 2 Temp8_OFF = 3 LastInkey_OFF = 4 CursorPos_OFF = 5 ; cursor position 0-159 BlitCtr_OFF = 6 MagicSys_OFF = 127 ; night right address ; MonitorRAM = 0x0800 MonitorRAM = Scratch SpaceChar = MonitorRAM + SpaceChar_OFF RWMode = MonitorRAM + RWMode_OFF NibHigh = MonitorRAM + NibHigh_OFF Temp8 = MonitorRAM + Temp8_OFF LastInkey = MonitorRAM + LastInkey_OFF CursorPos = MonitorRAM + CursorPos_OFF BlitCtr = MonitorRAM + BlitCtr_OFF MagicSys = MonitorRAM + MagicSys_OFF UserExec = 0x0900 ; to be moved to 0x1000 later Eprom8255 = 0x3000 EpromRA = Eprom8255 + 0 EpromRB = Eprom8255 + 1 EpromRC = Eprom8255 + 2 EpromCR = Eprom8255 + 3 ; --- IO SPACE ---- UART = 0x0000 ; tape uart ODDS8255 = 0x1000 TimerBase = 0x2000 Timer0 = TimerBase + 0 Timer1 = TimerBase + 1 Timer2 = TimerBase + 2 TimerControl = TimerBase + 3 Keyboard = 0x3000 LCDBot = 0x4000 ; instruction reg ; 0x4001 ; data reg LCDTop = 0x5000 ; instruction reg ; 0x5001 ; data reg ; = 0x6000 Beeper = 0x7000 .area _START (ABS) .ORG 0X00 JR INIT .ORG 0X08 CALL DynFunc ; call with 0xCF RETI .ORG 0X10 ; call with 0xD7 LD 0x7F(IY), B EI RETI .ORG 0X18 ; call with 0xDF JP INIT .ORG 0X20 ; call with 0xE7 JP INIT .ORG 0X28 ; call with 0xEF JP INIT .ORG 0X30 ; call with 0xF7 JP INIT .ORG 0X38 ; call with 0xFF JP INIT .ORG 0X66 ; NMI JP INIT INIT: ; INIT SYSTEM LD SP,#Stack ; SET UP STACK LD HL,#INIT ; A BIT OF OVER-RETURN PROTECTION PUSH HL LD BC,#ODDS8255+3 ; turn on blue keyboard led (8255 @ IO0x1000) LD A, #0x93 ; JUST PORT C-high OUTPUT OUT (C),A LD A, #0xBF ; only bit 8 low. DEC BC ; now pointing at port C OUT (C), A LD IY,#Scratch ; init function vector table CALL InitVectors ; this sets up the instruction LD, 0xFF(IY), nn to trigger the function nn LD A, #0x2E LD I, A IM 2 EI ; LD 0x7F(IY), #9*2 ; LSB MUST BE 0 LD HL,#3000 CALL LONGDELAY ; wait for power to come up LD BC,#ODDS8255+2 ; port C LD A, #0x7F ; only bit 7 low OUT (C),A CALL LCDINIT ; initialize lcd CALL ClearScrnBuff LD HL,#InitString CALL PRINTSTRING JR MEMREADMODE NEWADDRESS: ; GET NEW MEMORY ADDRESS CALL LCDFLUSH CALL GETADDR DOADDRESS: ; PERFORM CURRENT OPERATION ON ADDRESS BIT 0,RWMode_OFF(IY) ; STILL 5 CYCLES, BUT DOESN'T OVERWRITE A JP NZ,MEMWRITE CALL PRINTSPACE LD A,(HL) CALL PRINTBYTE CALL LCDFLUSH GETCMD: ; GET NEW COMMAND CALL INKEY LD D, A LD A,#0x0A ; LINEFEED CALL PUTC LD A, D CP #'I' ; INCREMENT ADDRESS JR Z,INCHL CP #'D' ; DECREMENT ADDRESS JR Z,DECHL CP #'R' ; READ MODE, NEW ADDRESS JR Z,MEMREADMODE CP #'W' ; WRITE MODE, NEW ADDRESS JR Z,MEMWRITEMODE CP #'P' ; PROGRAM 2716 EPROM JP Z,EPPROG CP #'G' ; GO TO USER CODE JR Z,GOUSER CP #'A' ; DO ADDRESS AGAIN JR Z,SAMEHL JR NEWADDRESS GOUSER: CALL ClearScrnBuff CALL LCDFLUSH CALL #UserExec JR NEWADDRESS INCHL: ; NEXT ADDRESS INC HL SAMEHL: CALL PRINTADDRESS JR DOADDRESS DECHL: DEC HL CALL PRINTADDRESS JR DOADDRESS MEMREADMODE: ; CHANGE TO READ MODE LD RWMode_OFF(IY),#0 LD SpaceChar_OFF(IY),#'=' JR NEWADDRESS MEMWRITEMODE: ; CHANGE TO WRITE MODE LD RWMode_OFF(IY),#0xFF LD SpaceChar_OFF(IY),#':' JR NEWADDRESS MEMWRITE: ; DO MEMORY WRITE CALL PRINTSPACE CALL LCDFLUSH CALL INBYTE LD (HL),A JR GETCMD ; ----------------------- 2716 EPROM PROGRAMMER ------------------------- EPPROG: CALL ClearScrnBuff CALL LCDFLUSH LD A,#'P' CALL PUTC LD A,#0x08 ; INIT 8255 LD (EpromCR),A LD A,#0x80 LD (EpromRC),A LD HL,#EndString CALL PRINTSTRING CALL LCDFLUSH CALL GETADDR EX DE,HL LD HL,#StartString CALL PRINTSTRING CALL LCDFLUSH PUSH DE CALL GETADDR POP DE NOP EPNEXT: LD A,L LD (EpromRB),A LD A,(HL) LD (EpromRA),A LD A,H AND #0x0F OR #0x80 LD (EpromRC),A CALL DELAY OR #0x40 LD (EpromRC),A CALL DELAY AND #0x8F LD (EpromRC),A CALL DELAY LD A,L CP E JP Z,EPLAST INC HL JP EPNEXT EPLAST: LD A,H CP D JP Z,EPLASTLAST INC HL JP EPNEXT EPLASTLAST: LD A,#0x80 LD (EpromRC),A LD A,#'K' CALL PUTC RET ;--------------------------- GET KEY ----------------------------- ; REGS OK. INKEY: CALL KEYUP PUSH BC LD BC,#0x3000 JP KEYTEST NOKEY: XOR A ; A = 0 CP C ; C = 0? JP Z, KEYTEST ; if yes, don't decrement it. DEC C KEYTEST: ; look for key down IN A,(C) ; get code OR A ; test for zero JP Z, NOKEY CP #0xFF ; multistrike? JP Z, NOKEY INC C ; debounce counter JP NZ, KEYTEST ; not charged yet. LD LastInkey_OFF(IY),A ; SAVE FOR KEYUP POP BC RET ; ----------------------- WAIT FOR KEYUP ---------------------------- ; REGS OK. KEYUP: PUSH AF PUSH BC STILLKEY: LD BC,#0x3000 NOISEKEY: IN A,(C) CP LastInkey_OFF(IY) JP Z,STILLKEY INC C JP NZ, NOISEKEY POP BC POP AF RET ; ------------------------- INPUT BYTE ------------------------------- ; REGS OK INBYTE: PUSH HL LD HL, #NibHigh CALL INKEY CALL ALTER LD (HL),A CALL PRINTLOW CALL INKEY CALL ALTER RLD LD A, (HL) CALL PRINTLOW LD A, (HL) POP HL RET ;------------------------------- ADJUST ASCII FOR HEX -------------------- ; REGS OK ALTER: CP #0x3A JP M,ALT1 SUB #0x07 ALT1: AND #0x0F RET ;--------------------------------- GET 16 BIT ADDRESS ------------------------ ; Result in HL ; REGS OK GETADDR: PUSH AF CALL INBYTE ;PUSH AF LD H,A CALL INBYTE ;POP HL LD L,A POP AF RET ; ----------------------------- PRINT CURRENT DELIM --------------------------- ; REGS OK PRINTSPACE: PUSH AF LD A,(SpaceChar) CALL PUTC POP AF RET ;------------------------- PRINT WORD ------------------------------ ; REGS OK PRINTADDRESS: PUSH AF LD A,H CALL PRINTBYTE LD A,L CALL PRINTBYTE POP AF RET ;------------------------- PRINT BYTE ------------------------------ ; REGS OK PRINTBYTE: PUSH AF RLCA RLCA RLCA RLCA CALL PRINTLOW POP AF ; CALL PRINTLOW ; RET ;------------------------ PRINT LOW NIBBLE -------------------------- ; REGS OK PRINTLOW: PUSH AF ;AND #0x0F ;OR #0x30 ;CP #0x3A ;JP M,PLNCORR ;ADD A,#0x07 AND #0X0F CP #0X0A SBC #0X69 DAA PLNCORR: CALL PUTC CALL LCDFLUSH POP AF RET ;--------------------------- WAIT FOR SCREEN ------------------------------ SCRNBUSYLOOP: IN A,(C) BIT 7,A JR NZ,SCRNBUSYLOOP RET ; -------------------------------- PRINT A STRING ------------------------------ ; A AND HL MODIFIED PRINTSTRING: LD A,(HL) OR A ; set flags, zero? RET Z CALL PUTC INC HL JR PRINTSTRING ;--------------------------- TOTALLY CLEAR SCEEN ------------------------------ ; REGS OK TOTALCLEAR: PUSH BC LD BC,#LCDTop CALL SCRNBUSYLOOP LD A,#0x01 ; clear display OUT (C),A CALL SCRNBUSYLOOP LD A,#0x0F ; display on, cursor on, blinking on OUT (C),A LD BC,#LCDBot CALL SCRNBUSYLOOP LD A,#0x01 ; clear display OUT (C),A CALL SCRNBUSYLOOP LD A,#0x0C ; display on, cursor off, blinking off OUT (C),A POP BC RET ;--------------------------- INITIALIZE SCREEN ------------------------------- LCDINIT: LD A,#0x38 ; 8 bit mode LD BC,#LCDTop OUT (C),A CALL SCRNBUSYLOOP LD A,#0x0F ; display on, cursor on, blinking on OUT (C),A LD B,#0x40 ; lcd top LD A,#0x38 ; 8 bit mode OUT (C),A CALL SCRNBUSYLOOP LD A,#0x0C ; display on, cursor off, blinking off OUT (C),A JR TOTALCLEAR ; FINISH BY CLEARNING THE SCREEN ; --------------------------------- DELAY ---------------------------------- ; REGS OK DELAY: PUSH BC LD C,#0x04 DLYOL: LD B,#0x19 DLYIL: DEC B JP NZ,DLYIL DEC C JP NZ,DLYOL POP BC RET ; --------------------------------- Variable DELAY ---------------------------------- ; HL (input value) will return 0x00 ;LONGDELAY: ; PUSH BC ; LD BC,#0xFFFF ; -1 ;LDLY1: ;ADC HL,BC ;JR NZ, LDLY1 ; POP BC ; RET ;LONGDELAY: ; PUSH AF ;LDLY1: ; DEC HL ; LD A,H ; TEST HL ; OR L ; JR NZ, LDLY1 ; ; POP AF ; RET LONGDELAY: DEC HL INC H INC L LDLY1: DEC L JR NZ,LDLY1 DEC H JR NZ,LDLY1 RET ; ------------------------------------ CHORDED BEEP ----------------------- CSTMBELL: LD BC,#Beeper LD H,#0x40 LD DE,#0xFEFE L029FH: LD A,D SUB #0x01 JP NZ,L02ACH OUT (C),A NOP DEC H RET Z LD A,#0xFE L02ACH: LD D,A LD A,E SUB #0x03 JP NZ,L02B8H OUT (C),A NOP LD A,#0xFE L02B8H: LD E,A JP L029FH ; ------------------------------------ init dynamic vector table ----------------------- ; DESTROYS BC,DE,HL InitVectors: LD BC,#50 LD HL,#VectTable LD DE,#Vectors LDIR DynReturn: RET ; ------------------------------------ dynamic system function call ----------------------- ; B IS THE DESIRED FUNCTION NUMBER 0-127 ; VECT_H IS HIGH BYTE OF TABLE DynFunc2: LD 0x7F(IY), B ; THIS WILL REQUIRE HARDWARE THAT I'LL BUILD LATER EI RET DynFunc: ; but for now... (IX IS DESTROYED, BUT NOTHING ELSE USES IT) PUSH HL SLA B .BYTE 0xDD, 0x26, #VECT_H ; LD IXH, #VECT_H OHHH WERE INTO CHEAT CODES NOW!!!! .BYTE 0xDD, 0X68 ; LD IXL, B LD L, 0x00(IX) ; LD HL, (IX) LD H, 0x01(IX) EX (SP),HL ; THE ORIG HL VALUE IS BACK IN HL, THE NEW ADDRESS IS ON STACK RET ; RETURNS TO ADDRESS ON STACK ;) ; ------------------------------------ blit from buffer to screen ----------------------- LCDFLUSH: PUSH AF PUSH BC PUSH DE PUSH HL CALL TOTALCLEAR LD HL,#0X2DB0 ; ** BOTTOM LSI DATA LD BlitCtr_OFF(IY),#80 ; loop counter LD BC,#LCDTop LD DE,#80 ; 16 bit maths BLITLOOP: OR A ; clear carry flag SBC HL,DE ; TOP LSI DATA SET 4,B ; top display CALL SCRNBUSYLOOP INC C ; data LD A,(HL) OUT (C),A DEC C ; command ADD HL,DE ; BOTTOM LSI DATA RES 4,B ; BOTTOM DISPLAY CALL SCRNBUSYLOOP INC C ; data LD A,(HL) OUT (C),A DEC C ; command INC L ; we dont have to increment HL casue the screen data doesn't cross a page. DEC BlitCtr_OFF(IY) JP NZ,BLITLOOP POP HL POP DE POP BC POP AF ; CALL LCDCrsPos ; LEAVE CURSOR IN THE RIGHT PLACE ; RET ; ------------------------------------ position the cursor on the module ----------------------- ; sets lcd cursor to position in CursorPos LCDCrsPos: PUSH AF PUSH BC LD BC,#LCDTop ; ASSUME TOP LD A, CursorPos_OFF(IY) CP #80 ; IS IT ON THE FIRST OR SECOND LSE? 80 IS THE FIRST POS OF THE BOTTOM JR C,DOPOSCRS1 ; jump if value is less than value SUB #80 ; ADJUST FOR BOTTOM LSI LD BC,#LCDBot DOPOSCRS1: CP #40 ; IS IT BEFORE OR AFTER THE STUPID ADDRESSING GAP? JR C, DOPOSCRS2 ADD #24 DOPOSCRS2: ; send 'on' to whoever were talking to. OR #0x80 ; POSITION COMMAND PUSH AF CALL SCRNBUSYLOOP POP AF OUT (C),A ; send command. CALL SCRNBUSYLOOP LD A,#0x0F ; display on, cursor on, blinking on OUT (C),A LD A, #0x10 ; other lsi XOR B LD B, A LD A,#0x0C ; display on, cursor off, blinking off OUT (C),A POP BC POP AF RET ; --------------------------------- Position cursor in buffer ------------------------ ; ok, its stupid but this does make it easier. BuffCrsPos: LD CursorPos_OFF(IY), A RET ; ------------------------------------ blit buffer clear ----------------------- ClearScrnBuff: PUSH AF PUSH BC PUSH HL LD B,#160 LD HL,#0x2D60 LD A,#' ' CLEARLOOP: LD (HL),A INC HL DJNZ CLEARLOOP ; DEC B, JR NZ,CLEARLOOP LD CursorPos_OFF(IY), #0 POP HL POP BC POP AF RET ; ------------------------------------ mapped lcd putchar ----------------------- PUTC: PUSH HL CP #0x0A ; LINEFEED? JP Z,PUTCLF PUSH AF LD HL,#0x2D60 ; POINTER TO BUFFER LOC LD A,CursorPos_OFF(IY) ; GET INSERT POSITION ADD A,L LD L,A POP AF LD (HL),A ; PUT CHAR INC CursorPos_OFF(IY) ; ADJUST POINTER LD A,#159 CP CursorPos_OFF(IY) ; WAS CURSOR AT LAST LOCATION? JP NZ, PUTCDONE LD CursorPos_OFF(IY), #120 ; position reset SCROLL1: PUSH BC PUSH DE LD BC,#120 ; MOVE 120 BYTES LD HL,#0x2D60+40 ; FROM 2nd line LD DE,#0x2D60 ; TO first line LDIR LD B, #40 LD A, #' ' CLRLINE: LD (DE), A INC DE DJNZ CLRLINE ; DEC B , JR NZ, CLRLINE POP DE POP BC PUTCDONE: POP HL RET PUTCLF: ; WHERE IS THE CURSOR? LD A, CursorPos_OFF(IY) ; GET INSERT POSITION CP A, #40 ; FRIST LINE? JP M, PUTCGOL2 ; THEN GO TO LINE 2 CP A, #80 JP M, PUTCGOL3 ; THEN GO TO LINE 3 CP A, #120 JP M, PUTCGOL4 ; THEN GO TO LINE 4 LD CursorPos_OFF(IY), #120 ; position reset JR SCROLL1 PUTCGOL2: LD CursorPos_OFF(IY), #40 JR PUTCDONE PUTCGOL3: LD CursorPos_OFF(IY), #80 JR PUTCDONE PUTCGOL4: LD CursorPos_OFF(IY), #120 JR PUTCDONE ;------------------------------------------ Timer Init --------------------------------- ; channel 0 will be the baud for the comm uart (CLK INPUT IS 9.21MHz) ; MODE 2, BINARY, divide by 5 (1.8MHz FOR 115200) ; channel 1 will be the baud for the tape uart (CLK INPUT IS 4MHz) ; MODE 2, BINARY, divide by 255 (15KHz FOR 244 BAUD) ; channel 2 will be the tape counter. (CLK INPUT IS TAPE SENSOR) ; MODE 0, BINARY, preset to 0xFFFF TimerInit: PUSH AF PUSH BC LD BC, #TimerControl LD A, #0x3A ; 0011.1010 Channel 0, write both, mode 5 in binary OUT (C), A LD A, #0x7A ; 0111.1010 Channel 1, write both, mode 5 in binary OUT (C), A LD A, #0xB0 ; 1011.0000 Channel 2, write both, mode 0 in binary OUT (C), A DEC BC ; NOW POINTING TO COUNTER 2, PRELOAD WITH 0XFFFF LD A,#0xFF OUT (C), A OUT (C), A DEC BC ; NOW POINTING TO COUNTER 1, PRELOAD WITH 255 OUT (C), A XOR A OUT (C), A DEC BC ; NOW POINTING TO COUNTER 0, PRELOAD WITH 5 LD A,#5 OUT (C), A XOR A OUT (C), A POP BC POP AF RET ;------------------------------------------ STRINGS AND TABLES --------------------------------- InitString: .ASCII " A-3 Monitor V3.4 \n" .BYTE 00 StartString: .ASCII " RAM START " .BYTE 00 EndString: .ASCII " RAM END " .BYTE 00 .BYTE 00 VectTable: .WORD DynFunc ; 0 2E00 THE DYNAMIC FUNCTION CALL ROUTINE .WORD TOTALCLEAR ; 1 2E02 HARDWARE LEVEL CLEAR SCREEN .WORD PUTC ; 2 2E04 BUFFER PUT CHAR .WORD PRINTBYTE ; 3 BUFFER PRINT HEX BYTE .WORD PRINTADDRESS ; 4 BUFFER PRINT HEX WORD .WORD PRINTSTRING ; 5 BUFFER PRINT STRING .WORD INKEY ; 6 GET KEYSTROKE, BLOCKING .WORD KEYUP ; 7 WAIT FOR RELEASE OF LAST PRESSED KEY, BLOCKING .WORD INBYTE ; 8 INPUT HEX BYTE .WORD GETADDR ; 9 INPUT HEX WORD .WORD ClearScrnBuff ; A CLEAR SCREEN BUFFER .WORD LCDFLUSH ; B PUSH BUFFER TO SCREEN .WORD LCDCrsPos ; C HARDWARE LEVEL LCD CURSOR POSITION .WORD BuffCrsPos ; D SCREEN BUFFER CURSOR POSITION .WORD INIT .WORD INIT