Fixed and improved some pce comments.

diff --git a/asminc/pce.inc b/asminc/pce.inc
index d603aae086311e428af8c11fef1e77709f4cf79c..8d141e8994eed2e2aba84241684be3e52b613ad6 100644 (file)
--- a/asminc/pce.inc
+++ b/asminc/pce.inc
@@ -13,8 +13,8 @@ CH_VLINE        = 2
 
 VDC_MAWR        = 0             ; Memory Address Write Register
 VDC_MARR        = 1             ; Memory Address Read Register
-VDC_VWR         = 2             ; VRAM Write Register (write only)
-VDC_VRR         = 2             ; VRAM Read Register (read only)
+VDC_VWR         = 2             ; VRAM Write Register
+VDC_VRR         = 2             ; VRAM Read Register
 VDC_UNK03       = 3             ; (unknown)
 VDC_UNK04       = 4             ; (unknown)
 VDC_CR          = 5             ; Control Register
@@ -35,8 +35,7 @@ VDC_SATB        = 19            ; Sprite Attribute Table
 
 ; VDC port
 ; Note:  The zero-page addressing mode is redirected to page $20.
-; Therefore, absolute addressing mode must be used when writing to this port.
-; We force it by using mirror locations that are outside of zero page.
+; We avoid it by using mirror locations that are outside of the zero page.
 
 VDC_CTRL        := $0200
 VDC_DATA_LO     := $0202
@@ -45,7 +44,7 @@ VDC_DATA_HI     := $0203
 ; HuC6260 -- Video Color Encoder (VCE)
 
 ; The DAC has a palette of 512 colours.
-; The bitmap of the palette data is this: 0000000gggrrrbbb.
+; The bitmap of that data is 0000000gggrrrbbb (Green, Red, Blue).
 ; You can read and write the DAC registers.
 
 VCE             := $0400        ; base
@@ -86,8 +85,8 @@ IRQ_STATUS      := $1403
 CDR_MEM_DISABLE := $1803
 CDR_MEM_ENABLE  := $1807
 
-; Write VDC register
-.macro VREG arg1,arg2
+; Write to a VDC register.
+.macro  VREG    arg1, arg2
         st0     #arg1
         st1     #<(arg2)
         st2     #>(arg2)

diff --git a/cfg/pce.cfg b/cfg/pce.cfg
index be0345fc47b2c01bc84b12046cc5c4fd08dcef81..eae9c1316d896aaae60f6b02987fb29fafc358fc 100644 (file)
--- a/cfg/pce.cfg
+++ b/cfg/pce.cfg
@@ -4,9 +4,9 @@ SYMBOLS {
     __STACKSIZE__: type = weak, value = $0300; # 3 pages stack
 }
 MEMORY {
-    ZP:   file = "", start =  $0000,                size = $0100,                 define = yes;
+    ZP:   file = "", start =  $0000, define = yes,  size = $0100;
     # RAM bank
-    MAIN: file = "", start =  $2200,                size = $1E00 - __STACKSIZE__, define = yes;
+    MAIN: file = "", start =  $2200, define = yes,  size = $1E00 - __STACKSIZE__;
     # ROM banks, before swapping, and after mapping
     ROM:  file = %O, start = $10000 - __CARTSIZE__, size = __CARTSIZE__, fill = yes, fillval = $FF;
 }

diff --git a/libsrc/pce/clock.s b/libsrc/pce/clock.s
index b71f1e2bcf18aa2047c08411e8e8ec0017381941..a57b6c4dac54be29e092557c36a1eb905e1bb8ea 100644 (file)
--- a/libsrc/pce/clock.s
+++ b/libsrc/pce/clock.s
@@ -3,9 +3,9 @@
 ;
 
         .export         _clock
-        .constructor    initclock, 24
+        .constructor    initclock
 
-        .forceimport    ticktock
+        .forceimport    ticktock        ; make sure that tickcount changes
         .importzp       sreg
 
         .include        "extzp.inc"
@@ -20,6 +20,9 @@
         rts
 .endproc
 
+
+; Make the process clock start at zero.
+
         .segment        "ONCE"
 initclock:
         lda     #0

diff --git a/libsrc/pce/clrscr.s b/libsrc/pce/clrscr.s
index 6ca12549ae6f2386e8fa2844f8c0731721cf7250..907a78899b73fe46a91fe00a5034e52f0ea6567f 100644 (file)
--- a/libsrc/pce/clrscr.s
+++ b/libsrc/pce/clrscr.s
@@ -1,3 +1,9 @@
+;
+; Clear (erase) the screen.
+;
+; Support the full 128- x 64-tile background.
+;
+
         .export         _clrscr
 
         .import         plot
@@ -15,9 +21,9 @@ _clrscr:
 rowloop:
         ldx     #$80
 colloop:
-        lda     #' '
+        lda     #' '            ; low byte of char. index
         sta     VDC_DATA_LO
-        lda     #$02
+        lda     #$02            ; background color, high nybble of char. index
         sta     VDC_DATA_HI
 
         dex

diff --git a/libsrc/pce/color.s b/libsrc/pce/color.s
index 4b8189db617ea80efd0c26032cacfb72d8e4302a..45eb9ffcd80d6b5fc5e68c74457250914dcf8cae 100644 (file)
--- a/libsrc/pce/color.s
+++ b/libsrc/pce/color.s
@@ -12,17 +12,17 @@
         .include        "pce.inc"
         .include        "extzp.inc"
 
-_bordercolor    := return0
+_bordercolor    := return0              ; always black
 
 _textcolor:
-        ldx     CHARCOLOR       ; get old value
-        sta     CHARCOLOR       ; set new value
+        ldx     CHARCOLOR               ; get old value
+        sta     CHARCOLOR               ; set new value
         txa
         rts
 
 _bgcolor:
-        ldx     BGCOLOR         ; get old value
-        sta     BGCOLOR         ; set new value
+        ldx     BGCOLOR                 ; get old value
+        sta     BGCOLOR                 ; set new value
         asl     a
         tay
 
@@ -43,7 +43,7 @@ colors: .word   ((0<<6)+(0<<3)+(0))     ; $0 black
         .word   ((7<<6)+(7<<3)+(7))     ; $1 white
         .word   ((0<<6)+(7<<3)+(0))     ; $2 red
         .word   ((7<<6)+(0<<3)+(7))     ; $3 cyan
-        .word   ((0<<6)+(5<<3)+(7))     ; $4 violett
+        .word   ((0<<6)+(5<<3)+(7))     ; $4 violet
         .word   ((7<<6)+(0<<3)+(0))     ; $5 green
         .word   ((0<<6)+(0<<3)+(7))     ; $6 blue
         .word   ((7<<6)+(7<<3)+(0))     ; $7 yellow

diff --git a/libsrc/pce/conio.s b/libsrc/pce/conio.s
index 35276c2396531261b8805096828774bdd1b47282..46907cc42e53c90a07123be10b16669aa848e9d6 100644 (file)
--- a/libsrc/pce/conio.s
+++ b/libsrc/pce/conio.s
@@ -28,7 +28,7 @@ set_palette:
 
         ldx     #0
 @lp:
-        ldy     #16
+        ldy     #16             ; size of a pallette
 @lp1:
         lda     colors,x
         sta     VCE_DATA_LO
@@ -42,6 +42,8 @@ set_palette:
         cpx     #16 * 2
         jne     @lp
 
+; Set background to black.
+
         stz     VCE_ADDR_LO
         stz     VCE_ADDR_HI
         stz     VCE_DATA_LO
@@ -49,13 +51,18 @@ set_palette:
 
         rts
 
+;----------------------------------------------------------------------------
+; The character tiles use only two colors from each pallette.  Color zero
+; comes from pallette zero; color one is different in each pallette.  The
+; color of a character is set by choosing one of the 16 pallettes.
+
 conio_init:
         ; Load font
         st0     #VDC_MAWR
         st1     #<$2000
         st2     #>$2000
 
-        ; ptr to font data
+        ; pointer to font data
         lda     #<font
         sta     ptr1
         lda     #>font
@@ -76,7 +83,7 @@ conio_init:
         sta     tmp1
         jsr     copy
 
-        ldx     #0
+        ldx     #0              ; white on black
         stx     BGCOLOR
         inx
         stx     CHARCOLOR
@@ -101,11 +108,11 @@ lineloop:
         adc     #$00
         sta     ptr1+1
         dex
-        bne     lineloop        ; next bitplane 0 byte
-        ldx     #$08            ; fill bitplane 2/3 with 0
+        bne     lineloop        ; next bitplane-0 byte
+        ldx     #$08            ; fill bitplanes 2 and 3 with 0
 fillloop:
-        st1     #$00
-        st2     #$00
+        st1     #<$0000
+        st2     #>$0000
         dex
         bne     fillloop        ; next byte
         dey

diff --git a/libsrc/pce/cputc.s b/libsrc/pce/cputc.s
index 5f720dd5767da54e2f0fd794372a89b49515cca5..5d9afdc93cbd96bc837f957422e6383685a4334a 100644 (file)
--- a/libsrc/pce/cputc.s
+++ b/libsrc/pce/cputc.s
@@ -25,10 +25,10 @@ _cputc: cmp     #$0D            ; CR?
         bne     L1
         lda     #0
         sta     CURS_X
-        beq     plot            ; Recalculate pointers
+        beq     plot            ; Recalculate pointer
 
 L1:     cmp     #$0A            ; LF?
-        beq     newline         ; Recalculate pointers
+        beq     newline         ; Recalculate pointer
 
 ; Printable char of some sort
 
@@ -50,23 +50,21 @@ L3:     sty     CURS_X
 newline:
         inc     CURS_Y
 
-; Set cursor position, calculate RAM pointers
+; Set cursor position; calculate VRAM pointer.
 
 plot:   ldy     CURS_X
         ldx     CURS_Y
         clc
         jmp     PLOT            ; Set the new cursor
 
-; Write one character to the screen without doing anything else, return X
-; position in Y
+; Write one character to the screen without doing anything else.
 
 putchar:
-
         ora     RVS             ; Set revers bit
 
         tax
 
-        st0     #VDC_MAWR       ; Memory Adress Write
+        st0     #VDC_MAWR       ; Memory Address Write
 
         lda     SCREEN_PTR
         sta     VDC_DATA_LO
@@ -79,8 +77,7 @@ putchar:
         txa
         sta     VDC_DATA_LO     ; character
 
-        lda     CHARCOLOR
-
+        lda     CHARCOLOR       ; pallette number
         asl     a
         asl     a
         asl     a

diff --git a/libsrc/pce/crt0.s b/libsrc/pce/crt0.s
index f5ed231867ca573d286674ce04c9d1c0b9a6bfcc..2b079727f7238b11e2ee31727c42ff4979a0eea2 100644 (file)
--- a/libsrc/pce/crt0.s
+++ b/libsrc/pce/crt0.s
@@ -36,7 +36,7 @@ start:  sei
         csh                     ; Set high-speed CPU mode
         nop
 
-        ; Set up stack and memory mapping
+        ; Set up stack and memory mapping.
         ldx     #$FF            ; Stack top ($21FF)
         txs
 
@@ -74,7 +74,7 @@ start:  sei
 
         ; Turn on background and VD interrupt/IRQ1
         lda     #$05
-        sta     IRQ_MASK        ; IRQ1=on
+        sta     IRQ_MASK        ; IRQ1 = on
 
         ; Copy the .data segment to RAM
         tii     __DATA_LOAD__, __DATA_RUN__, __DATA_SIZE__
@@ -87,7 +87,7 @@ start:  sei
         lda     #<(__MAIN_START__ + __MAIN_SIZE__ + __STACKSIZE__)
         ldx     #>(__MAIN_START__ + __MAIN_SIZE__ + __STACKSIZE__)
         sta     sp
-        stx     sp + 1
+        stx     sp+1
 
         ; Call module constructors
         jsr     initlib

diff --git a/libsrc/pce/ctype.s b/libsrc/pce/ctype.s
index aaedeb1a97d2e3f3962dd0a0c74646cdbce0d362..1ee51b23070c5131e4b2553e439203d74b83f17b 100644 (file)
--- a/libsrc/pce/ctype.s
+++ b/libsrc/pce/ctype.s
@@ -6,7 +6,7 @@
 
         .include        "ctype.inc"
 
-; The tables are readonly, put them into the rodata segment
+; The tables are read-only; put them into the RODATA segment.
 
 .rodata
 
@@ -23,7 +23,6 @@
 ;
 ;   * We save some code in the isxxx functions.
 
-
 __ctype:
         .repeat 2
         .byte   CT_CTRL                 ;   0/00 ___ctrl_@___

diff --git a/libsrc/pce/gotoxy.s b/libsrc/pce/gotoxy.s
index 379b02f7c9e50e485f24fab2bb7e9292d4809f51..dd7cbf1c2ebceff9197ceec25f41f8fef385266d 100644 (file)
--- a/libsrc/pce/gotoxy.s
+++ b/libsrc/pce/gotoxy.s
@@ -1,5 +1,5 @@
 ;
-; void gotoxy (unsigned char x, unsigned char y);
+; void __fastcall__ gotoxy (unsigned char x, unsigned char y);
 ;
 
         .export         gotoxy, _gotoxy

diff --git a/libsrc/pce/joy_stat_stddrv.s b/libsrc/pce/joy_stat_stddrv.s
index 2424c456b5b993d37e233e6f0b3eb28f828cf6ea..87af5617cd31eb60a47be52e28334c1d5bf56bd9 100644 (file)
--- a/libsrc/pce/joy_stat_stddrv.s
+++ b/libsrc/pce/joy_stat_stddrv.s
@@ -7,8 +7,7 @@
 ;
 
         .export         _joy_static_stddrv
-        .import         _pce_stdjoy_joy
 
-.rodata
+        .import         _pce_stdjoy_joy
 
 _joy_static_stddrv      := _pce_stdjoy_joy

diff --git a/libsrc/pce/psg.s b/libsrc/pce/psg.s
index 4e212dd3dfa6c0411d5d05350f25c6c43c36bed4..996b4e5aca86cd8cfd30c39131eea50d70cdec9f 100644 (file)
--- a/libsrc/pce/psg.s
+++ b/libsrc/pce/psg.s
@@ -5,7 +5,7 @@
         .segment        "ONCE"
 psg_init:
         clx
-        stz     PSG_GLOBAL_PAN          ; Clear global balance
+        stz     PSG_GLOBAL_PAN          ; Silence global balance
 
 psg_clear_loop:
         stx     PSG_CHAN_SELECT         ; Select channel

diff --git a/libsrc/pce/revers.s b/libsrc/pce/revers.s
index 5c5cd7fbeb57c49da7a585e8cb32d509f91c6cc1..b31ff150c306e32800589374ed3529f45a7900f4 100644 (file)
--- a/libsrc/pce/revers.s
+++ b/libsrc/pce/revers.s
@@ -1,7 +1,11 @@
+;
+; Ullrich von Bassewitz, 07.08.1998
+;
+; unsigned char revers (unsigned char onoff);
+;
 
         .export         _revers
 
-        .include        "pce.inc"
         .include        "extzp.inc"
 
 .proc   _revers
@@ -18,9 +22,3 @@ L2:     ldx     #$00            ; Load high byte of result
         tya                     ; Load low byte, set CC
         rts
 .endproc
-
-;-------------------------------------------------------------------------------
-; force the init constructor to be imported
-
-        .import         initconio
-conio_init      = initconio

diff --git a/libsrc/pce/vdc.s b/libsrc/pce/vdc.s
index 170be9cf506a0d72cfc73ca5ceeba0c409c175cb..e73004db88ce4e05d97a68492c3d49e61bdad75e 100644 (file)
--- a/libsrc/pce/vdc.s
+++ b/libsrc/pce/vdc.s
@@ -1,4 +1,3 @@
-
         .export         vdc_init
 
         .include        "pce.inc"
@@ -15,7 +14,7 @@ vdc_init:
         VREG    $06, $0000      ; RCR
         VREG    $07, $0000      ; BXR
         VREG    $08, $0000      ; BYR
-        VREG    $09, $0070      ; MAWR
+        VREG    $09, $0070      ; MWR
         VREG    $0C, $1702      ; CRTC - VSR
         VREG    $0D, $00DF      ; CRTC - VDS
         VREG    $0E, $000C      ; CRTC - VDE

diff --git a/libsrc/pce/waitvsync.s b/libsrc/pce/waitvsync.s
index 6cdfdda560c3380a3d427a7b6963e863a411d2a1..fed10c4e811ca2b53f15c99ceff1cb08310df298 100644 (file)
--- a/libsrc/pce/waitvsync.s
+++ b/libsrc/pce/waitvsync.s
@@ -6,9 +6,8 @@
 
         .export         _waitvsync
 
-        .forceimport    ticktock
+        .forceimport    ticktock        ; make sure that tickcount changes
 
-        .include        "pce.inc"
         .include        "extzp.inc"
 
 .proc   _waitvsync