<author>
<url url="mailto:stephan.muehlstrasser@web.de" name="Stephan Mühlstrasser">,<newline>
<url url="mailto:greg.king5@verizon.net" name="Greg King">
-<date>2015-03-08
+<date>2015-03-17
<abstract>
An overview over the Ohio Scientific runtime system as it is implemented for the cc65 C
<sect>Targets<p>
Currently the target "osic1p" is implemented. This works for the Ohio Scientific
-Challenger 1P machine.
+Challenger 1P machine and for the Briel Superboard /// replica.
<sect>Program file formats<p>
osic1p package comes with additional secondary linker config files, which are
used via <tt/-t osic1p -C <configfile>/.
-<sect1>
default config file (<tt/osic1p.cfg/)<p>
+<sect1>
Default config file (<tt/osic1p.cfg/)<p>
The default configuration is tailored to C programs.
There are no loadable drivers available.
+<sect>Support for different screen layouts<p>
+
+By default the conio library uses a 24 columns by 24 lines screen layout
+for the Challenger 1P, like under BASIC. In addition to that there is support
+for other screen layouts with extra modules.
+
+There is a module <tt/screen-c1p-24x24.o/ in the OSI-specific
+cc65 runtime library that contains all conio functions that depend
+on the screen layout. No further configuration is needed for using the
+default screen layout of the Challenger 1P.
+
+For other screen layouts additional versions of the screen module are
+available. The linker finds these modules without further configuration
+if they are specified on the compiler or linker command line. The
+extra module then overrides the default module.
+
+Sample <tt/cl65/ command line to override the default screen
+module with the module <tt/osic1p-screen-s3-32x28.o/:
+
+<tscreen><verb>
+cl65 -o hello -t osic1p osic1p-screen-s3-32x28.o hello.c
+</verb></tscreen>
+
+Currently the following extra screen configuration modules are implemented:
+
+<itemize>
+<item><tt>osic1p-screen-s3-32x28.o</tt>: 32 columns by 28 lines mode
+for Briel Superboard ///</item>
+</itemize>
+
<sect>Limitations<p>
<sect1>stdio implementation<p>
</enum>
</article>
+
+++ /dev/null
-;
-; based on PET implementation
-;
-; originally by:
-; Ullrich von Bassewitz, 26.10.2000
-;
-; Screen size variables
-;
-
- .export screensize
-
- .include "extzp.inc"
- .include "osic1p.inc"
-
-.proc screensize
- ldx #SCR_WIDTH
- ldy #SCR_HEIGHT
- rts
-.endproc
+++ /dev/null
-;\r
-; void clrscr (void);\r
-;\r
- .export _clrscr\r
- .import plot\r
- .include "extzp.inc"\r
- .include "osic1p.inc"\r
-\r
-; Adapted from the Challenger Character Graphics\r
-; Reference Manual, "2.3.3 MACHINE LANGUAGE SCREEN CLEAR"\r
-; This is self-modifying code!\r
-BANKS = VIDEORAMSIZE / $100\r
-\r
-_clrscr:\r
- lda #' '\r
- ldy #BANKS\r
- ldx #$00\r
-staloc:\r
- sta SCRNBASE,X\r
- inx\r
- bne staloc\r
- inc staloc+2\r
- dey\r
- bne staloc\r
- lda #>(SCRNBASE) ; Load high byte\r
- sta staloc+2 ; Restore base address\r
-\r
- lda #$00 ; Cursor in upper left corner\r
- sta CURS_X\r
- sta CURS_Y\r
- jmp plot ; Set the cursor position\r
+++ /dev/null
-;
-; cputc/cputcxy for Challenger 1P
-; Based on PET/CBM implementation
-;
-; void cputcxy (unsigned char x, unsigned char y, char c);
-; void cputc (char c);
-;
- .export _cputcxy, _cputc, cputdirect, putchar
- .export newline, plot
- .import popa, _gotoxy
-
- .include "osic1p.inc"
- .include "extzp.inc"
-
-FIRSTVISC = $85 ; Offset of first visible character in video RAM
-LINEDIST = $20 ; Offset in video RAM between two lines
-BLOCKSIZE = $100 ; Size of block to scroll
-
-_cputcxy:
- pha ; Save C
- jsr popa ; Get Y
- jsr _gotoxy ; Set cursor, drop x
- pla ; Restore C
-
-; Plot a character - also used as internal function
-
-_cputc: cmp #$0A ; CR?
- bne L1
- lda #0
- sta CURS_X
- beq plot ; Recalculate pointers
-
-L1: cmp #$0D ; LF?
- beq newline ; Recalculate pointers
-
-cputdirect:
- jsr putchar ; Write the character to the screen
-
-; Advance cursor position
-
-advance:
- cpy #(SCR_WIDTH - 1)
- bne L3
- jsr newline ; New line
- ldy #$FF ; + cr
-L3: iny
- sty CURS_X
- rts
-
-newline:
- inc CURS_Y
- lda CURS_Y
- cmp #SCR_HEIGHT ; Screen height
- bne plot
- dec CURS_Y ; Bottom of screen reached, scroll
- ldx #0
-scroll:
-.repeat 3, I ; Scroll screen in three blocks of size
- ; BLOCKSIZE
- lda SCRNBASE+(I*BLOCKSIZE)+FIRSTVISC+LINEDIST,x
- sta SCRNBASE+(I*BLOCKSIZE)+FIRSTVISC,x
-.endrepeat
- inx
- bne scroll
-
- lda #' ' ; Clear bottom line of screen
-bottom:
- sta SCRNBASE+(3*BLOCKSIZE)+FIRSTVISC,x
- inx
- cpx #SCR_WIDTH
- bne bottom
-
-plot: ldy CURS_Y
- lda ScrLo,y
- sta SCREEN_PTR
- lda ScrHi,y
- sta SCREEN_PTR+1
- rts
-
-; Write one character to the screen without doing anything else, return X
-; position in Y
-
-putchar:
- ldy CURS_X
- sta (SCREEN_PTR),y ; Set char
- rts
-
-; Screen address tables - offset to real screen
-
-.rodata
-
-ScrLo: .byte $85, $A5, $C5, $E5, $05, $25, $45, $65
- .byte $85, $A5, $C5, $E5, $05, $25, $45, $65
- .byte $85, $A5, $C5, $E5, $05, $25, $45, $65
- .byte $85
-
-ScrHi: .byte $D0, $D0, $D0, $D0, $D1, $D1, $D1, $D1
- .byte $D1, $D1, $D1, $D1, $D2, $D2, $D2, $D2
- .byte $D2, $D2, $D2, $D2, $D3, $D3, $D3, $D3
- .byte $D3
--- /dev/null
+;
+; Implementation of screen-layout related functions for Superboard ///
+;
+
+ .include "../osiscreen.inc"
+
+S3_SCR_BASE := $D000 ; Base of Superboard /// video RAM
+S3_VRAM_SIZE = $0400 ; Size of Superboard /// video RAM (1 kB)
+S3_SCR_WIDTH = $20 ; Screen width
+S3_SCR_HEIGHT = $1C ; Screen height
+S3_SCR_FIRSTCHAR = $80 ; Offset of cursor position (0, 0) from base
+ ; of video RAM
+S3_SCROLL_DIST = $20 ; Memory distance for scrolling by one line
+
+osi_screen_funcs S3_SCR_BASE, S3_VRAM_SIZE, S3_SCR_FIRSTCHAR, \
+ S3_SCR_WIDTH, S3_SCR_HEIGHT, S3_SCROLL_DIST
; Addresses\r
-SCRNBASE := $D000 ; Base of video RAM\r
INPUTC := $FD00 ; Input character from keyboard\r
RESET := $FF00 ; Reset address, show boot prompt\r
KBD := $DF00 ; Polled keyboard register\r
-\r
-; Other definitions\r
-VIDEORAMSIZE = $0400 ; Size of C1P video RAM (1 kB)\r
-SCR_WIDTH = $18 ; Screen width\r
-SCR_HEIGHT = $18 ; Screen height\r
--- /dev/null
+;\r
+; Macro definitions for screen layout modules\r
+;\r
+\r
+ .include "extzp.inc"\r
+ \r
+.linecont +\r
+\r
+;\r
+; Internal function for screensize()\r
+;\r
+.macro osi_screensize ScrWidth, ScrHeight\r
+ ; Macro implementation of internal screensize\r
+ ; function for given width and height in\r
+ ; characters\r
+ \r
+ .export screensize\r
+\r
+.proc screensize\r
+ ldx #ScrWidth\r
+ ldy #ScrHeight\r
+ rts\r
+.endproc\r
+.endmacro\r
+\r
+;\r
+; void clrscr (void);\r
+;\r
+.macro osi_clrscr ScrBase, ScrRamSize\r
+\r
+ .export _clrscr\r
+\r
+.proc _clrscr\r
+ lda #<ScrBase ; Fill whole video RAM with blanks by calling\r
+ ldx #>ScrBase ; memset appropriately\r
+ jsr pushax\r
+ \r
+ lda #' '\r
+ ldx #$00\r
+ jsr pushax\r
+ \r
+ lda #<ScrRamSize\r
+ ldx #>ScrRamSize\r
+ jsr _memset\r
+\r
+ lda #$00 ; Cursor in upper left corner\r
+ sta CURS_X\r
+ sta CURS_Y\r
+ \r
+ jmp plot ; Set the cursor position\r
+.endproc\r
+\r
+.endmacro\r
+\r
+;\r
+; cputc/cputcxy for Challenger 1P\r
+; Based on PET/CBM implementation\r
+;\r
+\r
+.macro osi_cputfuncs ScrBase, ScrFirstChar, ScrWidth, ScrHeight, \\r
+ ScrollDist, ScrLo, ScrHi\r
+\r
+ ; Number of characters to move for scrolling\r
+ ; by one line\r
+ScrollLength = (ScrHeight - 1) * ScrollDist\r
+\r
+;\r
+; void cputcxy (unsigned char x, unsigned char y, char c);\r
+; void cputc (char c);\r
+;\r
+ .export _cputcxy, _cputc, cputdirect, putchar\r
+ .export newline, plot\r
+\r
+_cputcxy:\r
+ pha ; Save C\r
+ jsr popa ; Get Y\r
+ jsr _gotoxy ; Set cursor, drop x\r
+ pla ; Restore C\r
+\r
+; Plot a character - also used as internal function\r
+\r
+_cputc: cmp #$0A ; CR?\r
+ bne L1\r
+ lda #0\r
+ sta CURS_X\r
+ beq plot ; Recalculate pointers\r
+\r
+L1: cmp #$0D ; LF?\r
+ beq newline ; Recalculate pointers\r
+\r
+cputdirect:\r
+ jsr putchar ; Write the character to the screen\r
+\r
+; Advance cursor position, register Y contains horizontal position after\r
+; putchar\r
+\r
+ cpy #(ScrWidth - 1) ; Check whether line is full\r
+ bne L3\r
+ jsr newline ; New line\r
+ ldy #$FF ; + cr\r
+L3: iny\r
+ sty CURS_X\r
+ rts\r
+\r
+newline:\r
+ inc CURS_Y\r
+ lda CURS_Y\r
+ cmp #ScrHeight ; Screen height\r
+ bne plot\r
+ dec CURS_Y ; Bottom of screen reached, scroll\r
+\r
+ ; Scroll destination address\r
+ lda #<(ScrBase + ScrFirstChar)\r
+ ldx #>(ScrBase + ScrFirstChar)\r
+ jsr pushax\r
+ \r
+ ; Scroll source address\r
+ lda #<(ScrBase + ScrFirstChar + ScrollDist)\r
+ ldx #>(ScrBase + ScrFirstChar + ScrollDist)\r
+ jsr pushax\r
+ \r
+ ; Number of characters to move\r
+ lda #<ScrollLength\r
+ ldx #>ScrollLength\r
+ jsr _memmove\r
+\r
+ ; Address of first character in last line\r
+ ; of screen\r
+ lda #<(ScrBase + ScrFirstChar + ScrollLength)\r
+ sta ptr1\r
+ lda #>(ScrBase + ScrFirstChar + ScrollLength)\r
+ sta ptr1+1\r
+ \r
+ ldy #ScrWidth ; Fill last line with blanks\r
+ lda #' '\r
+clrln: sta (ptr1),y\r
+ dey\r
+ bpl clrln\r
+\r
+plot: ldy CURS_Y\r
+ lda ScrLo,y\r
+ sta SCREEN_PTR\r
+ lda ScrHi,y\r
+ sta SCREEN_PTR+1\r
+ rts\r
+\r
+; Write one character to the screen without doing anything else, return X\r
+; position in register Y\r
+\r
+putchar:\r
+ ldy CURS_X\r
+ sta (SCREEN_PTR),y ; Set char\r
+ rts\r
+ \r
+.endmacro\r
+\r
+.macro osi_screen_funcs ScrBase, ScrRamSize, ScrFirstChar, \\r
+ ScrWidth, ScrHeight, ScrollDist\r
+\r
+ .import popa, _gotoxy\r
+ .import _memmove, _memset, pushax\r
+ .importzp ptr1\r
+\r
+.rodata\r
+\r
+; Screen address tables - offset to real screen\r
+ScrTabLo:\r
+ .repeat ScrHeight, I\r
+ .byte <(ScrBase + ScrFirstChar + I * ScrollDist)\r
+ .endrep\r
+ \r
+ScrTabHi:\r
+ .repeat ScrHeight, I\r
+ .byte >(ScrBase + ScrFirstChar + I * ScrollDist)\r
+ .endrep\r
+\r
+.code\r
+\r
+osi_cputfuncs ScrBase, ScrFirstChar, ScrWidth, ScrHeight, \\r
+ ScrollDist, ScrTabLo, ScrTabHi\r
+osi_screensize ScrWidth, ScrHeight\r
+osi_clrscr ScrBase, ScrRamSize\r
+\r
+.endmacro
\ No newline at end of file
--- /dev/null
+;
+; Implementation of screen-layout related functions for Challenger 1P
+;
+
+ .include "osiscreen.inc"
+
+C1P_SCR_BASE := $D000 ; Base of C1P video RAM
+C1P_VRAM_SIZE = $0400 ; Size of C1P video RAM (1 kB)
+C1P_SCR_WIDTH = $18 ; Screen width
+C1P_SCR_HEIGHT = $18 ; Screen height
+C1P_SCR_FIRSTCHAR = $85 ; Offset of cursor position (0, 0) from base
+ ; of video RAM
+C1P_SCROLL_DIST = $20 ; Memory distance for scrolling by one line
+
+osi_screen_funcs C1P_SCR_BASE, C1P_VRAM_SIZE, C1P_SCR_FIRSTCHAR, \
+ C1P_SCR_WIDTH, C1P_SCR_HEIGHT, C1P_SCROLL_DIST
projects / cc65 / commitdiff