Applecorn/auxmem.misc.s
2021-09-02 15:47:03 -04:00

452 lines
14 KiB
ArmAsm

* AUXMEM.MISC.S
* (c) Bobbi 2021 GPLv3
*
* Misc functions and API entry block
* 02-Sep-2021 Written GSINIT/GSREAD
* OSBYTE $80 - ADVAL
************************************
* Read input device or buffer status
BYTE80 LDY #$00 ; Prepare return=&00xx
TXA ; X<0 - info about buffers
BMI ADVALBUF ; X>=0 - read input devices
CPX #$7F
BNE ADVALNONE
ADVALWAIT JSR KBDREAD
BCS ADVALWAIT
TAX
BPL ADVALOK1 ; &00xx for normal keys
INY ; &01xx for function/edit keys
ADVALOK1 RTS
ADVALNONE LDX #$00 ; Input, just return 0
RTS
ADVALBUF INX
BEQ :ADVALKBD ; Fake keyboard buffer
INX
BEQ :ADVALOK ; Serial input, return 0
LDX #$01 ; For outputs, return 1 char free
RTS
:ADVALKBD BIT $C000 ; Test keyboard data/strobe
BPL :ADVALOK ; No Strobe, return 0
INX ; Strobe, return 1
:ADVALOK RTS
******************
* Helper functions
******************
* Beep
*
* Sound measurement shows the tone formula is:
* 1.230 MHz
* ------------- = cycles
* 8 * frequency
*
* cycles = BEEPX*5+10
*
* So:
* BEEPX = (cycles-10)/5
* So:
* BEEPX = ( 1.230 MHz )
* (------------- - 10 ) / 5
* (8 * frequency )
* BEEPX EQU #57 ; note=C5
BEEPX EQU #116 ; note=C4
BEEP PHA
PHX
PHY
LDY #$00 ; duration
:L1 LDX #BEEPX ; 2cy pitch 2cy
*------------------------------------------------------
:L2 DEX ; 2cy BEEPX * 2cy
BNE :L2 ; 3cy/2cy (BEEPX-1) * 3cy + 1 * 2cy
*------------------------------------------------------
* BEEPX*5-1cy
LDA $C030 ; 4cy BEEPX*5+5
DEY ; 2cy BEEPX*5+7
BNE :L1 ; 3cy/2cy BEEPX*5+10
PLY ;
PLX
PLA
RTS
** Delay approx 1/100 sec
*************************
** Enter at DELAY with CS to test keyboard
** Enter at CENTI to ignore keyboard
**
*CENTI CLC ; Don't test keyboard
*DELAY PHX ; 3cy
* PHY ; 3cy
* LDY #10 ; 2cy 10 * 1/1000s
**------------------------------------------------
*:L1 LDX #$48 ; 2cy $48 gives about 1/1000s
*:L2 BCC :L3 ; 2cy/3cy Don't test kbd
* LDA $C000 ; 4cy
* BMI :L5 ; 2cy keypress, exit early
*:L3 DEX ; 2cy
* BNE :L2 ; 3cy/2cy -> 72*(2+2+4+2+2+3)-1
** ; = 1079 -> 0.00105s
**------------------------------------------------
*:L4 DEY ; 2cy
* BNE :L1 ; 3cy/2cy
*:L5 PLY ; 4cy
* PLX ; 4cy
* RTS ; 6cy
* Print string pointed to by X,Y to the screen
OUTSTR TXA
* Print string pointed to by A,Y to the screen
PRSTR STA OSTEXT+0 ; String in A,Y
STY OSTEXT+1
:L1 LDA (OSTEXT) ; Ptr to string in ZP3
BEQ PRSTROK
JSR OSASCI
INC OSTEXT
BNE :L1
INC OSTEXT+1
BRA :L1
PRSTROK RTS
* Print NL if not already at column 0
FORCENL LDA #$86
JSR OSBYTE
TXA
BEQ PRSTROK
JMP OSNEWL
* Print XY in hex
OUT2HEX TYA
JSR OUTHEX
TAX ; Continue into OUTHEX
* Print hex byte in A
OUTHEX PHA
LSR
LSR
LSR
LSR
AND #$0F
JSR PRNIB
PLA
AND #$0F ; Continue into PRNIB
* Print hex nibble in A
PRNIB CMP #$0A
BCC :S1
CLC ; >= $0A
ADC #'A'-$0A
JSR OSWRCH
RTS
:S1 ADC #'0' ; < $0A
JMP OSWRCH
* GSINIT - Initialise for GSTRANS string parsing
************************************************
* On entry,
* (OSLPTR),Y=>start of string (spaces will be skipped)
* CLC = filename style parsing
* SEC = *KEY style parsing
* On exit,
* X = preserved
* Y = prepared for future calls to GSREAD
* EQ = end of line (nb: not "" null string)
* NE = not end of line
*
* Very difficult to write this without it being a direct clone
* from the BBC MOS. ;)
*
GSINTGO ROR GSFLAG ; CY initially into bit 7
JSR SKIPSPC ; Skip any spaces
INY ; Step past in case it's a quote
CMP #$22 ; Is it a quote?
BEQ GSINTGO1
DEY ; Wasn't a quote, step back
CLC ; Prepare CC=no leading quote
GSINTGO1 ROR GSFLAG ; Rotate 'leading-quote' into flags
CMP #$0D
RTS ; Return EQ if end of line
* GSFLAG set to:
* bit7: leading quote found
* bit6: CC=filename CS=*KEY
* GSREAD - Read a character from a GSTRANS parsed string
********************************************************
* On entry,
* (OSLPTR),Y=>current string pointer
* On exit,
* A = parsed character
* X = preserved
* CS = end of string (space or <cr> or ")
* Y =updated to start of next word or end of line
* EQ=end of line after this string
* NE=not end of line, more words follow
* CC = not end of string
* Y =updated for future calls to GSREAD
* VS=control character, <$20
* VC=not control character >$1F
*
* No string present is checked for with:
* JSR GSINIT:BEQ missingstring
*
* A null string is checked for with:
* JSR GSINIT:JSR GSREAD:BCS nullstring
*
* A string is skipped with:
* JSR GSINIT
* loop
* JSR GSREAD:BCC loop
*
* A string is copied with:
* JSR GSINIT
* LDX #0
* loop
* JSR GSREAD:BCS done
* STA data,X
* INX:BNE loop
* done
*
GSRDGO LDA #$00 ; Prepare to clear accumulator
GSREADLP STA GSCHAR ; Update accumulator
LDA (OSLPTR),Y ; Get current character
CMP #$0D ; End of line?
BNE GSREAD2 ; No, check character
BIT GSFLAG
BPL GSREADEND ; We aren't waiting for a closing quote
* ; End of line before closing quote
ERRBADSTR BRK
DB $FD
ASC 'Bad string'
BRK
GSREAD2 CMP #' '
BCC ERRBADSTR ; Embedded control char
BNE GSREAD3 ; Not a space, process it
BIT GSFLAG ; Can space terminate string?
BMI GSREADCHAR ; We're waiting for a terminating quote
* ; so return the space character
BVC GSREADEND ; Space is a terminator, finish
GSREAD3 CMP #$22 ; Is it a quote?
BNE GSREADESC ; Not quote, check for escapes
BIT GSFLAG ; Was there an opening quote?
BPL GSREADCHAR ; Not waiting for a closing quote
INY ; Waiting for quote, check next character
LDA (OSLPTR),Y
CMP #$22 ; Is it another quote?
BEQ GSREADCHAR ; Quote-Quote, expand to single quote
* End of string
* Either closing quote, or a space seperator, or end of line
GSREADEND JSR SKIPSPC ; Skip any spaces to next word
SEC ; SEC=end of string
RTS ; and (OSLPTR),Y=>next word or end of line
* CS=end of string
* EQ=end of line
* NE=not end of line, more words follow
GSREADESC CMP #$7C ; Is is '|' escape character
BNE GSREADCHAR ; No, return as character
INY ; Step to next character
LDA (OSLPTR),Y
CMP #$7C
BEQ GSREADCHAR ; bar-bar expands to bar
CMP #$22
BEQ GSREADCHAR ; bar-quote expands to quote
CMP #'!' ; Is it bar-pling?
BNE GSREAD5 ; No, check for bar-letter
INY ; Step past it
LDA #$80 ; Set bit 7 in accumulator
BNE GSREADLP ; Loop back to check next character(s)
GSREAD5 CMP #'?' ; Check for '?'
BCC ERRBADSTR ; <'?', bad character
BEQ GSREADDEL ; bar-query -> DEL
AND #$1F ; Convert bar-letter to control code
BIT SETV ; SEV=control character
BVS GSREADOK
GSREADDEL LDA #$7F
GSREADCHAR CLV ; CLV=not control character
GSREADOK INY ; Step to next character
ORA GSCHAR ; Add in any bit 7 from |! prefix
CLC ; CLC=not end of string
RTS
* CC=not end of string
* VS=control character
* VC=not control character
* Read a byte from sideways ROM
RDROM LDX #$0F ; Returns X=current ROM, Y=0, A=byte
LDY #$00 ; We haven't really got any ROMs
LDA ($F6),Y ; so just read directly
RTS
EVENT LDA #<OSEVENM
LDY #>OSEVENM
JMP PRSTR
OSEVENM ASC 'OSEVEN.'
DB $00
**********************************************************
* Interrupt Handlers, MOS redirection vectors etc.
**********************************************************
* Invoked from GSBRK in main memory. On IIgs only.
GSBRKAUX >>> IENTAUX ; IENTAUX does not do CLI
* Continue into IRQBRKHDLR
* TO DO: Check, IENTAUX modifies X
* IRQ/BRK handler
IRQBRKHDLR PHA
* Mustn't enable IRQs within the IRQ handler
* Do not use WRTMAIN/WRTAUX macros
STA $C004 ; Write to main memory
STA $45 ; $45=A for ProDOS IRQ handlers
STA $C005 ; Write to aux memory
TXA
PHA
CLD
TSX
LDA $103,X ; Get PSW from stack
AND #$10
BEQ :IRQ ; IRQ
SEC
LDA $0104,X
SBC #$01
STA FAULT
LDA $0105,X
SBC #$00
STA FAULT+1
PLA
TAX
PLA
CLI
JMP (BRKV) ; Pass on to BRK handler
:IRQ >>> XF2MAIN,A2IRQ ; Bounce to Apple IRQ handler
IRQBRKRET
>>> IENTAUX ; IENTAUX does not do CLI
PLA ; TODO: Pass on to IRQ1V
TAX
PLA
NULLRTI RTI
PRERR LDY #$01
PRERRLP LDA (FAULT),Y
BEQ PRERR1
JSR OSWRCH
INY
BNE PRERRLP
NULLRTS
PRERR1 RTS
MOSBRKHDLR LDA #<MSGBRK
LDY #>MSGBRK
JSR PRSTR
JSR PRERR
JSR OSNEWL
JSR OSNEWL
STOP JMP STOP ; Cannot return from a BRK
MSGBRK DB $0D
ASC "ERROR: "
DB $00
* Default page 2 contents
DEFVEC DW NULLRTS ; $200 USERV
DW MOSBRKHDLR ; $202 BRKV
DW NULLRTI ; $204 IRQ1V
DW NULLRTI ; $206 IRQ2V
DW CLIHND ; $208 CLIV
DW BYTEHND ; $20A BYTEV
DW WORDHND ; $20C WORDV
DW WRCHHND ; $20E WRCHV
DW RDCHHND ; $210 RDCHV
DW FILEHND ; $212 FILEV
DW ARGSHND ; $214 ARGSV
DW BGETHND ; $216 BGETV
DW BPUTHND ; $218 BPUTV
DW GBPBHND ; $21A GBPBV
DW FINDHND ; $21C FINDV
DW FSCHND ; $21E FSCV
ENDVEC
*
* Acorn MOS entry points at the top of RAM
* Copied from loaded code to high memory
*
* Base of API entries here in loaded code
MOSVEC
* Real base of API entries in real memory
MOSAPI EQU $FFB6
ORG MOSAPI
* OPTIONAL ENTRIES
* ----------------
*OSSERV JMP SERVICE ; FF95 OSSERV
*OSCOLD JMP NULLRTS ; FF98 OSCOLD
*OSPRSTR JMP OUTSTR ; FF9B OSPRSTR
*OSFF9E JMP NULLRTS ; FF9E
*OSSCANHEX JMP RDHEX ; FFA1 SCANHX
*OSFFA4 JMP NULLRTS ; FFA4
*OSFFA7 JMP NULLRTS ; FFA7
*PRHEX JMP OUTHEX ; FFAA PRHEX
*PR2HEX JMP OUT2HEX ; FFAD PR2HEX
*OSFFB0 JMP NULLRTS ; FFB0
*OSWRRM JMP NULLRTS ; FFB3 OSWRRM
* COMPULSARY ENTRIES
* ------------------
VECSIZE DB ENDVEC-DEFVEC ; FFB6 VECSIZE Size of vectors
VECBASE DW DEFVEC ; FFB7 VECBASE Base of default vectors
OSRDRM JMP RDROM ; FFB9 OSRDRM Read byte from paged ROM
OSCHROUT JMP OUTCHAR ; FFBC CHROUT Send char to VDU driver
OSEVEN JMP EVENT ; FFBF OSEVEN Signal an event
GSINIT JMP GSINTGO ; FFC2 GSINIT Init string reading
GSREAD JMP GSRDGO ; FFC5 GSREAD Parse general string
NVWRCH JMP WRCHHND ; FFC8 NVWRCH Nonvectored WRCH
NVRDCH JMP RDCHHND ; FFCB NVRDCH Nonvectored RDCH
OSFIND JMP (FINDV) ; FFCE OSFIND
OSGBPB JMP (GBPBV) ; FFD1 OSGBPB
OSBPUT JMP (BPUTV) ; FFD4 OSBPUT
OSBGET JMP (BGETV) ; FFD7 OSBGET
OSARGS JMP (ARGSV) ; FFDA OSARGS
OSFILE JMP (FILEV) ; FFDD OSFILE
OSRDCH JMP (RDCHV) ; FFE0 OSRDCH
OSASCI CMP #$0D ; FFE3 OSASCI
BNE OSWRCH
OSNEWL LDA #$0A ; FFE7 OSNEWL
JSR OSWRCH
OSWRCR LDA #$0D ; FFEC OSWRCR
OSWRCH JMP (WRCHV) ; FFEE OSWRCH
OSWORD JMP (WORDV) ; FFF1 OSWORD
OSBYTE JMP (BYTEV) ; FFF4 OSBYTE
OSCLI JMP (CLIV) ; FFF7 OSCLI
NMIVEC DW NULLRTI ; FFFA NMIVEC
RSTVEC DW STOP ; FFFC RSTVEC
IRQVEC
* Assembler doesn't like running up to $FFFF, so we bodge a bit
MOSEND
ORG MOSEND-MOSAPI+MOSVEC
DW IRQBRKHDLR ; FFFE IRQVEC
MOSVEND
* Buffer for one 512 byte disk block in aux mem
AUXBLK ASC '**ENDOFCODE**'
DS $200-13