sms: WIP !

blk/001

@@ -8,7 +8,7 @@ MASTER INDEX
 280 Z80 boot code             390 Cross-compiled core
 490 TRS-80 Recipe             520 Fonts
 550 TI-84+ Recipe             580 RC2014 Recipe
-
+620 Sega Master System Recipe
 
 
 

blk/209

@@ -8,4 +8,4 @@ JP [nn, (HL), (IX), (IY)]
 JR [, Z, NZ, C, NC]
 
 DI         EI          EXDEHL      EXX         HALT
-NOP        RET         SCF
+NOP        RET         RETI        RETN        SCF

blk/224

@@ -5,4 +5,5 @@
 0xed5e OP2 IM2,
 0xeda0 OP2 LDI,                0xedb0 OP2 LDIR,
 0xeda8 OP2 LDD,                0xedb8 OP2 LDDR,
-0xed44 OP2 NEG,                0xed4d OP2 RETI,
+0xed44 OP2 NEG,
+0xed4d OP2 RETI,               0xed45 OP2 RETN,

blk/620

@@ -0,0 +1,3 @@
+Sega Master System Recipe
+
+622 VDP

blk/622

@@ -0,0 +1,16 @@
+VDP Driver
+
+Implement (emit) on the console. Characters start at the top
+left. Every (emit) call converts the ASCII char received to its
+internal font, then put that char on screen, advancing the
+cursor by one. When reaching the end of the line (33rd char),
+wrap to the next.
+
+In the future, there's going to be a scrolling mechanism when
+we reach the bottom of the screen, but for now, when the end of
+the screen is reached, we wrap up to the top.
+
+When reaching a new line, we clear that line and the next to
+help readability.
+
+Load range: 623-623

blk/623

@@ -0,0 +1,9 @@
+CODE _ctl ( a -- sends LSB then MSB )
+    HL POPqq, chkPS,
+    A L LDrr, VDP_CTLPORT OUTnA,
+    A H LDrr, VDP_CTLPORT OUTnA,
+;CODE
+CODE _data
+    HL POPqq, chkPS,
+    A L LDrr, VDP_DATAPORT OUTnA,
+;CODE

blk/624

@@ -0,0 +1,10 @@
+CODE _blank ( this is way too slow in Forth )
+    A XORr, VDP_CTLPORT OUTnA,
+    A 0x40 LDrn, VDP_CTLPORT OUTnA,
+    HL 0x4000 LDddnn,
+    BEGIN,
+        A XORr, VDP_DATAPORT OUTnA,
+        HL DECss, HLZ,
+    JRNZ, AGAIN,
+;CODE
+

blk/625

@@ -0,0 +1,10 @@
+CREATE _idat
+0b00000100 C, 0x80 C, ( Bit 2: Select mode 4 )
+0b00000000 C, 0x81 C,
+0b11111111 C, 0x82 C, ( Name table: 0x3800 )
+0b11111111 C, 0x85 C, ( Sprite table: 0x3f00 )
+0b11111111 C, 0x86 C, ( sprite use tiles from 0x2000 )
+0b11111111 C, 0x87 C, ( Border uses palette 0xf )
+0b00000000 C, 0x88 C, ( BG X scroll )
+0b00000000 C, 0x89 C, ( BG Y scroll )
+0b11111111 C, 0x8a C, ( Line counter (why have this?) )

blk/626

@@ -0,0 +1,12 @@
+: _zero ( x -- send 0 _data x times )
+    ( x ) 0 DO 0 _data LOOP ;
+
+( Each row in ~FNT is a row of the glyph and there is 7 of
+them.  We insert a blank one at the end of those 7. For each
+row we set, we need to send 3 zero-bytes because each pixel in
+the tile is actually 4 bits because it can select among 16
+palettes. We use only 2 of them, which is why those bytes
+always stay zero. )
+: _sfont ( a -- Send font to VDP )
+    7 0 DO C@+ _data 3 _zero LOOP DROP
+    ( blank row ) 4 _zero ;

blk/627

@@ -0,0 +1,14 @@
+: _set ( row col tilenum -- )
+    ROT 5 LSHIFT ROT OR 0x7800 OR _ctl
+    _data 1 _zero
+;
+: VDP$
+    9 0 DO _idat I 2 * + @ _ctl LOOP _blank
+    ( palettes )
+    0xc000 _ctl
+    ( BG ) 1 _zero 0x3f _data 14 _zero
+    ( sprite, inverted colors ) 0x3f _data 15 _zero
+    0x4000 _ctl 0x5e 0 DO ~FNT I 7 * + _sfont LOOP
+    0 0 1 _set
+;
+

emul/hw/sms/sms.c

@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <stdbool.h>
+#include <unistd.h>
 
 #include <xcb/xcb.h>
 
@@ -155,7 +156,11 @@ void draw_pixels()
 void event_loop()
 {
     while (1) {
-        emul_step();
+        if (!emul_step()) {
+            fprintf(stderr, "CPU halted, quitting\n");
+            usleep(1000 * 1000);
+            break;
+        }
         if (vdp_changed) {
             // To avoid overdrawing, we'll let the CPU run a bit to finish its
             // drawing operation.

recipes/sms/Makefile

@@ -1,10 +1,16 @@
-TARGET = os.sms
-BASEDIR = ../..
-ZASM = $(BASEDIR)/emul/zasm/zasm
-KERNEL = $(BASEDIR)/kernel
-APPS = $(BASEDIR)/apps
+TARGET = os.bin
+STAGE = ../../emul/stage
+EMUL = ../../emul/hw/sms/sms
 
 .PHONY: all
 all: $(TARGET) 
-$(TARGET): glue.asm
-	$(ZASM) $(KERNEL) $(APPS) < glue.asm > $@
+$(TARGET): xcomp.fs $(STAGE)
+	cat xcomp.fs | $(STAGE) > $@
+
+$(EMUL):
+	$(MAKE) -C ${@:%/sms=%}
+
+.PHONY: emul
+emul: $(EMUL) $(TARGET)
+	$(EMUL) $(TARGET)
+	

recipes/sms/xcomp.fs

@@ -0,0 +1,32 @@
+( 8K of onboard RAM )
+0xc000 CONSTANT RAMSTART
+0xdd00 CONSTANT RS_ADDR
+( Memory register at the end of RAM. Must not overwrite )
+0xddca CONSTANT PS_ADDR
+0xbf   CONSTANT VDP_CTLPORT
+0xbe   CONSTANT VDP_DATAPORT
+32     CONSTANT VDP_COLS
+24     CONSTANT VDP_ROWS
+212 LOAD  ( z80 assembler )
+: ZFILL, ( u ) 0 DO 0 A, LOOP ;
+262 LOAD  ( xcomp )
+524 LOAD  ( font compiler )
+270 LOAD  ( xcomp overrides )
+
+0x100 JPnn, 0x63 ZFILL, ( 0x66 )
+RETN, 0x98 ZFILL, ( 0x100 )
+( All set, carry on! )
+CURRENT @ XCURRENT !
+0x100 BIN( !
+282 LOAD  ( boot.z80 )
+393 LOAD  ( xcomp core low )
+CREATE ~FNT CPFNT7x7
+623 627 LOADR ( VDP )
+: (key) 0 ; : (emit) DROP ;
+420 LOAD  ( xcomp core high )
+(entry) _
+( Update LATEST )
+PC ORG @ 8 + !
+," VDP$ BYE "
+ORG @ 0x100 - 256 /MOD 2 PC! 2 PC!
+H@ 256 /MOD 2 PC! 2 PC!