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diff --git a/docs/os12/mdfs.net/Docs/Comp/BBC/OS1-20/CA39 b/docs/os12/mdfs.net/Docs/Comp/BBC/OS1-20/CA39 new file mode 100644 index 0000000..576492f --- /dev/null +++ b/docs/os12/mdfs.net/Docs/Comp/BBC/OS1-20/CA39 @@ -0,0 +1 @@ +*************************************************************************
* *
* VDU 24 - DEFINE GRAPHICS WINDOW *
* *
* 8 parameters *
* *
*************************************************************************
;&31C/D Left margin
;&31E/F Bottom margin
;&320/1 Right margin
;&322/3 Top margin
CA39 JSR &CA81 ;exchange 310/3 with 328/3
CA3C LDX #&1C ;
CA3E LDY #&2C ;
CA40 JSR &D411 ;calculate width=right - left
; height = top-bottom
CA43 ORA &032D ;
CA46 BMI &CA81 ;exchange 310/3 with 328/3 and exit
CA48 LDX #&20 ;X=&20
CA4A JSR &D149 ;scale pointers to mode
CA4D LDX #&1C ;X=&1C
CA4F JSR &D149 ;scale pointers to mode
CA52 LDA &031F ;check for negative margins
CA55 ORA &031D ;
CA58 BMI &CA81 ;if found exchange 310/3 with 328/3 and exit
CA5A LDA &0323 ;
CA5D BNE &CA81 ;exchange 310/3 with 328/3 and exit
CA5F LDX &0355 ;screen mode
CA62 LDA &0321 ;right margin hi
CA65 STA &DA ;store it
CA67 LDA &0320 ;right margin lo
CA6A LSR &DA ;/2
CA6C ROR ;A=A/2
CA6D LSR &DA ;/2
CA6F BNE &CA81 ;exchange 310/3 with 328/3
CA71 ROR ;A=A/2
CA72 LSR ;A=A/2
CA73 CMP C3EF,X ;text window right hand margin maximum
CA76 BEQ &CA7A ;if equal CA7A
CA78 BPL &CA81 ;exchange 310/3 with 328/3
CA7A LDY #&00 ;Y=0
CA7C LDX #&1C ;X=&1C
CA7E JSR &D47C ;set(300/7+Y) from (300/7+X)
***************** exchange 310/3 with 328/3 *****************************
CA81 LDX #&10 ;X=10
CA83 LDY #&28 ;Y=&28
CA85 JMP &CDE6 ;exchange 300/3+Y and 300/3+X
CA88 INY ;Y=Y+1
CA89 TYA ;A=Y
CA8A LDY #&00 ;Y=0
CA8C STY &034D ;text window width hi (bytes)
CA8F STA &034C ;text window width lo (bytes)
CA92 LDA &034F ;bytes per character
CA95 LSR ;/2
CA96 BEQ &CAA1 ;if 0 exit
CA98 ASL &034C ;text window width lo (bytes)
CA9B ROL &034D ;text window width hi (bytes)
CA9E LSR ;/2
CA9F BCC &CA98 ;
CAA1 RTS ;
*************************************************************************
* *
* VDU 29 - SET GRAPHICS ORIGIN *
* *
* 4 parameters *
* *
*************************************************************************
;
CAA2 LDX #&20 ;
CAA4 LDY #&0C ;
CAA6 JSR &D48A ;(&300/3+Y)=(&300/3+X)
CAA9 JMP &D1B8 ;set up external coordinates for graphics
*************************************************************************
* *
* VDU 127 (&7F) - DELETE (entry 32) *
* *
*************************************************************************
CAAC JSR &C5C5 ;cursor left
CAAF JSR &C588 ;A=0 if text cursor A=&20 if graphics cursor
CAB2 BNE &CAC7 ;if graphics then CAC7
CAB4 LDX &0360 ;number of logical colours less 1
CAB7 BEQ &CAC2 ;if mode 7 CAC2
CAB9 STA &DE ;else store A (always 0)
CABB LDA #&C0 ;A=&C0
CABD STA &DF ;store in &DF (&DE) now points to C300 SPACE pattern
CABF JMP &CFBF ;display a space
CAC2 LDA #&20 ;A=&20
CAC4 JMP &CFDC ;and return to display a space
CAC7 LDA #&7F ;for graphics cursor
CAC9 JSR &D03E ;set up character definition pointers
CACC LDX &035A ;Background graphics colour
CACF LDY #&00 ;Y=0
CAD1 JMP &CF63 ;invert pattern data (to background colour)
***** Add number of bytes in a line to X/A ******************************
CAD4 PHA ;store A
CAD5 TXA ;A=X
CAD6 CLC ;clear carry
CAD7 ADC &0352 ;bytes per character row
CADA TAX ;X=A
CADB PLA ;get back A
CADC ADC &0353 ;bytes per character row
CADF RTS ;and return
;
********* control scrolling in paged mode *******************************
CAE0 JSR &CB14 ;zero paged mode line counter
CAE3 JSR &E9D9 ;osbyte 118 check keyboard status; set LEDs
CAE6 BCC &CAEA ;if carry clear CAEA
CAE8 BMI &CAE0 ;if M set CAE0 do it again
CAEA LDA &D0 ;VDU status byte
CAEC EOR #&04 ;invert bit 2 paged scrolling
CAEE AND #&46 ;and if 2 cursors, paged mode off, or scrolling
CAF0 BNE &CB1C ;barred then CB1C to exit
CAF2 LDA &0269 ;paged mode counter
CAF5 BMI &CB19 ;if negative then exit via CB19
CAF7 LDA &0319 ;current text line
CAFA CMP &0309 ;bottom margin
CAFD BCC &CB19 ;increment line counter and exit
CAFF LSR ;A=A/4
CB00 LSR ;
CB01 SEC ;set carry
CB02 ADC &0269 ;paged mode counter
CB05 ADC &030B ;top of text window
CB08 CMP &0309 ;bottom margin
CB0B BCC &CB19 ;increment line counter and exit
CB0D CLC ;clear carry
CB0E JSR &E9D9 ;osbyte 118 check keyboard status; set LEDs
CB11 SEC ;set carry
CB12 BPL &CB0E ;if +ve result then loop till shift pressed
**************** zero paged mode counter *******************************
CB14 LDA #&FF ;
CB16 STA &0269 ;paged mode counter
CB19 INC &0269 ;paged mode counter
CB1C RTS ;
;
*********part of intitialisation routines ******************************
CB1D PHA ;save A
CB1E LDX #&7F ;X=&7F
CB20 LDA #&00 ;A=0
CB22 STA &D0 ;VDU status byte to set default conditions
CB24 STA &02FF,X ;zero 300,37E
CB27 DEX ;with this loop
CB28 BNE &CB24 ;
CB2A JSR &CD07 ;implode character definitions
CB2D PLA ;get back A
CB2E LDX #&7F ;X=&7F
CB30 STX &0366 ;mode 7 write cursor character
CB33 BIT &028E ;available RAM pages
CB36 BMI &CB3A ;if 32k CB3A
CB38 ORA #&04 ;ensure only modes 4-7 are available
CB3A AND #&07 ;X=A and 7 ensure legal mode
CB3C TAX ;X=mode
CB3D STX &0355 ;set screen mode flag
CB40 LDA &C414,X ;no. of colours -1 in mode table
CB43 STA &0360 ;number of logical colours less 1
CB46 LDA &C3FF,X ;number of bytes /character for each mode
CB49 STA &034F ;bytes per character
CB4C LDA &C43A,X ;display mode pixels/byte table
CB4F STA &0361 ;pixels per byte
CB52 BNE &CB56 ;if <> 0 CB56
CB54 LDA #&07 ;else A=7
CB56 ASL ;A=A*2
CB57 TAY ;Y=A
CB58 LDA &C406,Y ;mask table
CB5B STA &0363 ;colour mask left
CB5E ASL ;A=A*2
CB5F BPL &CB5E ;If still +ve CB5E
CB61 STA &0362 ;colour mask right
CB64 LDY &C440,X ;screen display memory index table
CB67 STY &0356 ;memory map type
CB6A LDA &C44F,Y ;VDU section control
CB6D JSR &E9F8 ;set hardware scrolling to VIA
CB70 LDA &C44B,Y ;VDU section control
CB73 JSR &E9F8 ;set hardware scrolling to VIA
CB76 LDA &C459,Y ;Screen RAM size hi byte table
CB79 STA &0354 ;screen RAM size hi byte
CB7C LDA &C45E,Y ;screen ram address hi byte
CB7F STA &034E ;hi byte of screen RAM address
CB82 TYA ;Y=A
CB83 ADC #&02 ;Add 2
CB85 EOR #&07 ;
CB87 LSR ;/2
CB88 TAX ;X=A
CB89 LDA &C466,X ;row multiplication table pointer
CB8C STA &E0 ;store it
CB8E LDA #&C3 ;A=&C3
CB90 STA &E1 ;store it (&E0) now points to C3B5 or C375
CB92 LDA &C463,X ;get nuber of bytes per row from table
CB95 STA &0352 ;store as bytes per character row
CB98 STX &0353 ;bytes per character row
CB9B LDA #&43 ;A=&43
CB9D JSR &C5A8 ;A=A and &D0:&D0=A
CBA0 LDX &0355 ;screen mode
CBA3 LDA &C3F7,X ;get video ULA control setting
CBA6 JSR &EA00 ;set video ULA using osbyte 154
CBA9 PHP ;push flags
CBAA SEI ;set interrupts
CBAB LDX &C469,Y ;get cursor end register data from table
CBAE LDY #&0B ;Y=11
CBB0 LDA &C46E,X ;get end of 6845 registers 0-11 table
CBB3 JSR &C95E ;set register Y
CBB6 DEX ;reduce pointers
CBB7 DEY ;
CBB8 BPL &CBB0 ;and if still >0 do it again
CBBA PLP ;pull flags
CBBB JSR &C839 ;set default colours
CBBE JSR &C9BD ;set default windows
CBC1 LDX #&00 ;X=0
CBC3 LDA &034E ;hi byte of screen RAM address
CBC6 STX &0350 ;window area start address lo
CBC9 STA &0351 ;window area start address hi
CBCC JSR &C9F6 ;use X and Y to set new cursor address
CBCF LDY #&0C ;Y=12
CBD1 JSR &CA2B ;set registers 12 and 13 in CRTC
CBD4 LDA &0358 ;background text colour
CBD7 LDX &0356 ;memory map type
CBDA LDY &C454,X ;get section control number
CBDD STY &035D ;set it in jump vector lo
CBE0 LDY #&CC ;Y=&CC
CBE2 STY &035E ;upper byte of link address
CBE5 LDX #&00 ;X=0
CBE7 STX &0269 ;paged mode counter
CBEA STX &0318 ;text column
CBED STX &0319 ;current text line
CBF0 JMP (&035D) ;jump vector set up previously
*************************************************************************
* *
* OSWORD 10 - READ CHARACTER DEFINITION *
* *
*************************************************************************
;&EF=A:&F0=X:&F1=Y, on entry YX contains number of byte to be read
;(&DE) points to address
;on exit byte YX+1 to YX+8 contain definition
CBF3 JSR &D03E ;set up character definition pointers
CBF6 LDY #&00 ;Y=0
CBF8 LDA (&DE),Y ;get first byte
CBFA INY ;Y=Y+1
CBFB STA (&F0),Y ;store it in YX
CBFD CPY #&08 ;until Y=8
CBFF BNE &CBF8 ;
CC01 RTS ;then exit
;
*************************************************************************
* *
* MAIN SCREEN CLEARANCE ROUTINE *
* *
*************************************************************************
;on entry A contains background colour which is set in every byte
;of the screen
************************ Mode 0,1,2 entry point *************************
CC02 STA &3000,X ;
CC05 STA &3100,X ;
CC08 STA &3200,X ;
CC0B STA &3300,X ;
CC0E STA &3400,X ;
CC11 STA &3500,X ;
CC14 STA &3600,X ;
CC17 STA &3700,X ;
CC1A STA &3800,X ;
CC1D STA &3900,X ;
CC20 STA &3A00,X ;
CC23 STA &3B00,X ;
CC26 STA &3C00,X ;
CC29 STA &3D00,X ;
CC2C STA &3E00,X ;
CC2F STA &3F00,X ;
************************ Mode 3 entry point *****************************
CC32 STA &4000,X ;
CC35 STA &4100,X ;
CC38 STA &4200,X ;
CC3B STA &4300,X ;
CC3E STA &4400,X ;
CC41 STA &4500,X ;
CC44 STA &4600,X ;
CC47 STA &4700,X ;
CC4A STA &4800,X ;
CC4D STA &4900,X ;
CC50 STA &4A00,X ;
CC53 STA &4B00,X ;
CC56 STA &4C00,X ;
CC59 STA &4D00,X ;
CC5C STA &4E00,X ;
CC5F STA &4F00,X ;
CC62 STA &5000,X ;
CC65 STA &5100,X ;
CC68 STA &5200,X ;
CC6B STA &5300,X ;
CC6E STA &5400,X ;
CC71 STA &5500,X ;
CC74 STA &5600,X ;
CC77 STA &5700,X ;
************************ Mode 4,5 entry point ***************************
CC7A STA &5800,X ;
CC7D STA &5900,X ;
CC80 STA &5A00,X ;
CC83 STA &5B00,X ;
CC86 STA &5C00,X ;
CC89 STA &5D00,X ;
CC8C STA &5E00,X ;
CC8F STA &5F00,X ;
************************ Mode 6 entry point *****************************
CC92 STA &6000,X ;
CC95 STA &6100,X ;
CC98 STA &6200,X ;
CC9B STA &6300,X ;
CC9E STA &6400,X ;
CCA1 STA &6500,X ;
CCA4 STA &6600,X ;
CCA7 STA &6700,X ;
CCAA STA &6800,X ;
CCAD STA &6900,X ;
CCB0 STA &6A00,X ;
CCB3 STA &6B00,X ;
CCB6 STA &6C00,X ;
CCB9 STA &6D00,X ;
CCBC STA &6E00,X ;
CCBF STA &6F00,X ;
CCC2 STA &7000,X ;
CCC5 STA &7100,X ;
CCC8 STA &7200,X ;
CCCB STA &7300,X ;
CCCE STA &7400,X ;
CCD1 STA &7500,X ;
CCD4 STA &7600,X ;
CCD7 STA &7700,X ;
CCDA STA &7800,X ;
CCDD STA &7900,X ;
CCE0 STA &7A00,X ;
CCE3 STA &7B00,X ;
************************ Mode 7 entry point *****************************
CCE6 STA &7C00,X ;
CCE9 STA &7D00,X ;
CCEC STA &7E00,X ;
CCEF STA &7F00,X ;
CCF2 INX ;
CCF3 BEQ &CD65 ;exit
****************** execute required function ****************************
CCF5 JMP (&035D) ;jump vector set up previously
********* subtract bytes per line from X/A ******************************
CCF8 PHA ;Push A
CCF9 TXA ;A=X
CCFA SEC ;set carry for subtraction
CCFB SBC &0352 ;bytes per character row
CCFE TAX ;restore X
CCFF PLA ;and A
CD00 SBC &0353 ;bytes per character row
CD03 CMP &034E ;hi byte of screen RAM address
CD06 RTS ;return
*************************************************************************
* *
* OSBYTE 20 - EXPLODE CHARACTERS *
* *
*************************************************************************
;
CD07 LDA #&0F ;A=15
CD09 STA &0367 ;font flag indicating that page &0C,&C0-&C2 are
;used for user defined characters
CD0C LDA #&0C ;A=&0C
CD0E LDY #&06 ;set loop counter
CD10 STA &0368,Y ;set all font location bytes
CD13 DEY ;to page &0C to indicate only page available
CD14 BPL &CD10 ;for user character definitions
CD16 CPX #&07 ;is X= 7 or greater
CD18 BCC &CD1C ;if not CD1C
CD1A LDX #&06 ;else X=6
CD1C STX &0246 ;character definition explosion switch
CD1F LDA &0243 ;A=primary OSHWM
CD22 LDX #&00 ;X=0
CD24 CPX &0246 ;character definition explosion switch
CD27 BCS &CD34 ;
CD29 LDY &C4BA,X ;get soft character RAM allocation
CD2C STA &0368,Y ;font location bytes
CD2F ADC #&01 ;Add 1
CD31 INX ;X=X+1
CD32 BNE &CD24 ;if X<>0 then CD24
CD34 STA &0244 ;current value of page (OSHWM)
CD37 TAY ;Y=A
CD38 BEQ &CD06 ;return via CD06 (ERROR?)
CD3A LDX #&11 ;X=&11
CD3C JMP &F168 ;issue paged ROM service call &11
;font implosion/explosion warning
******** move text cursor to next line **********************************
CD3F LDA #&02 ;A=2 to check if scrolling disabled
CD41 BIT &D0 ;VDU status byte
CD43 BNE &CD47 ;if scrolling is barred CD47
CD45 BVC &CD79 ;if cursor editing mode disabled RETURN
CD47 LDA &0309 ;bottom margin
CD4A BCC &CD4F ;if carry clear on entry CD4F
CD4C LDA &030B ;else if carry set get top of text window
CD4F BVS &CD59 ;and if cursor editing enabled CD59
CD51 STA &0319 ;get current text line
CD54 PLA ;pull return link from stack
CD55 PLA ;
CD56 JMP &C6AF ;set up cursor and display address
CD59 PHP ;push flags
CD5A CMP &0365 ;Y coordinate of text input cursor
CD5D BEQ &CD78 ;if A=line count of text input cursor CD78 to exit
CD5F PLP ;get back flags
CD60 BCC &CD66 ;
CD62 DEC &0365 ;Y coordinate of text input cursor
CD65 RTS ;exit
;
CD66 INC &0365 ;Y coordinate of text input cursor
CD69 RTS ;exit
*********************** set up write cursor ********************************
CD6A PHP ;save flags
CD6B PHA ;save A
CD6C LDY &034F ;bytes per character
CD6F DEY ;Y=Y-1
CD70 BNE &CD8F ;if Y=0 Mode 7 is in use
CD72 LDA &0338 ;so get mode 7 write character cursor character &7F
CD75 STA (&D8),Y ;store it at top scan line of current character
CD77 PLA ;pull A
CD78 PLP ;pull flags
CD79 RTS ;and exit
;
CD7A PHP ;push flags
CD7B PHA ;push A
CD7C LDY &034F ;bytes per character
CD7F DEY ;
CD80 BNE &CD8F ;if not mode 7
CD82 LDA (&D8),Y ;get cursor from top scan line
CD84 STA &0338 ;store it
CD87 LDA &0366 ;mode 7 write cursor character
CD8A STA (&D8),Y ;store it at scan line
CD8C JMP &CD77 ;and exit
CD8F LDA #&FF ;A=&FF =cursor
CD91 CPY #&1F ;except in mode 2 (Y=&1F)
CD93 BNE &CD97 ;if not CD97
CD95 LDA #&3F ;load cursor byte mask
********** produce white block write cursor *****************************
CD97 STA &DA ;store it
CD99 LDA (&D8),Y ;get scan line byte
CD9B EOR &DA ;invert it
CD9D STA (&D8),Y ;store it on scan line
CD9F DEY ;decrement scan line counter
CDA0 BPL &CD99 ;do it again
CDA2 BMI &CD77 ;then jump to &CD77
CDA4 JSR &CE5B ;exchange line and column cursors with workspace copies
CDA7 LDA &0309 ;bottom margin
CDAA STA &0319 ;current text line
CDAD JSR &CF06 ;set up display address
CDB0 JSR &CCF8 ;subtract bytes per character row from this
CDB3 BCS &CDB8 ;wraparound if necessary
CDB5 ADC &0354 ;screen RAM size hi byte
CDB8 STA &DB ;store A
CDBA STX &DA ;X
CDBC STA &DC ;A again
CDBE BCS &CDC6 ;if C set there was no wraparound so CDC6
CDC0 JSR &CE73 ;copy line to new position
;using (&DA) for read
;and (&D8) for write
CDC3 JMP &CDCE ;
CDC6 JSR &CCF8 ;subtract bytes per character row from X/A
CDC9 BCC &CDC0 ;if a result is outside screen RAM CDC0
CDCB JSR &CE38 ;perform a copy
CDCE LDA &DC ;set write pointer from read pointer
CDD0 LDX &DA ;
CDD2 STA &D9 ;
CDD4 STX &D8 ;
CDD6 DEC &DE ;decrement window height
CDD8 BNE &CDB0 ;and if not zero CDB0
CDDA LDX #&28 ;point to workspace
CDDC LDY #&18 ;point to text column/line
CDDE LDA #&02 ;number of bytes to swap
CDE0 BNE &CDE8 ;exchange (328/9)+Y with (318/9)+X
CDE2 LDX #&24 ;point to graphics cursor
CDE4 LDY #&14 ;point to last graphics cursor
;A=4 to swap X and Y coordinates
*************** exchange 300/3+Y with 300/3+X ***************************
CDE6 LDA #&04 ;A =4
************** exchange (300/300+A)+Y with (300/300+A)+X *****************
CDE8 STA &DA ;store it as loop counter
CDEA LDA &0300,X ;get byte
\ No newline at end of file |