sms: simplify and solidify ports-related drivers

Add _TRA!, _THA!, _TRB!, _THB! routines to easily handle those pins'
value without stepping on other pins like the drivers previously
did. For SDC driver, it's going to be important soon because it turns
out that I can't get away with "always on" CS, so I'll need a scheme
where it's important that TH/TR pins have stable values.

arch/z80/sms/blk/600

@@ -1,4 +1,4 @@
 Sega Master System Recipe
 
 602 VDP                        610 PAD
-620 KBD
+620 KBD                        625 Ports

arch/z80/sms/blk/613

@@ -1,15 +1,7 @@
-CODE _status
-    A 0b11111101 LDri, ( TH output, unselected )
-    PAD_CTLPORT OUTiA,
-    PAD_D1PORT INAi,
-    0x3f ANDi, ( low 6 bits are good )
-    H A LDrr,  ( let's store them )
+: _status
+    1 _THA! ( output, high/unselected )
+    _D1@ 0x3f AND ( low 6 bits are good )
 ( Start and A are returned when TH is selected, in bits 5 and
   4. Well get them, left-shift them and integrate them to B. )
-    A 0b11011101 LDri, ( TH output, selected )
-    PAD_CTLPORT OUTiA,
-    PAD_D1PORT INAi,
-    0b00110000 ANDi,
-    A SLA, A SLA, H ORr,
-    PUSHA,
-;CODE
+    0 _THA! ( output, low/selected )
+    _D1@ 0x30 AND 2 LSHIFT OR ;

arch/z80/sms/blk/620

@@ -4,10 +4,9 @@
 is something to read. When the adapter is finished filling its
 '164 up, it resets the latch, which output's is connected to
 TL. When the '164 is full, TL is low. Port A TL is bit 4 )
-    0xdc PC@ 0x10 AND IF 0 EXIT ( nothing ) THEN
-    0x3f PC@ DROP 0b11011101 ( Port A TH output, low ) 0x3f PC!
-    0xdc PC@ ( bit 3:0 go in 3:0 ) 0x0f AND ( n )
-    0b11111101 ( Port A TH output, high ) 0x3f PC!
-    0xdc PC@ ( bit 3:0 go in 7:4 ) 0x0f AND 4 LSHIFT OR ( n )
-	( Port A/B reset ) 0xff 0x3f PC!
-;
+    _D1@ 0x10 AND IF 0 EXIT ( nothing ) THEN
+    0 _THA! ( Port A TH output, low )
+    _D1@ ( bit 3:0 go in 3:0 ) 0x0f AND ( n )
+    1 _THA! ( Port A TH output, high )
+    _D1@ ( bit 3:0 go in 7:4 ) 0x0f AND 4 LSHIFT OR ( n )
+	2 _THA! ( TH input ) ;

arch/z80/sms/blk/621

@@ -1,11 +1,10 @@
 : (ps2kcB) ( for port B )
 	( Port B TL is bit 2 )
-    0xdd PC@ 0x04 AND IF 0 EXIT ( nothing ) THEN
-    0x3f PC@ DROP 0b01110111 ( Port B TH output, low ) 0x3f PC!
-    0xdc PC@ ( bit 7:6 go in 1:0 ) 6 RSHIFT ( n )
-    0xdd PC@ ( bit 1:0 go in 3:2 ) 0x03 AND 2 LSHIFT OR ( n )
-    0b11110111 ( Port B TH output, high ) 0x3f PC!
-    0xdc PC@ ( bit 7:6 go in 5:4 ) 0xc0 AND 2 RSHIFT OR ( n )
-    0xdd PC@ ( bit 1:0 go in 7:6 ) 0x03 AND 6 LSHIFT OR ( n )
-	( Port A/B reset ) 0xff 0x3f PC!
-;
+    _D2@ 0x04 AND IF 0 EXIT ( nothing ) THEN
+    0 _THB! ( Port B TH output, low )
+    _D1@ ( bit 7:6 go in 1:0 ) 6 RSHIFT ( n )
+    _D2@ ( bit 1:0 go in 3:2 ) 0x03 AND 2 LSHIFT OR ( n )
+    1 _THB! ( Port B TH output, high )
+    _D1@ ( bit 7:6 go in 5:4 ) 0xc0 AND 2 RSHIFT OR ( n )
+    _D2@ ( bit 1:0 go in 7:6 ) 0x03 AND 6 LSHIFT OR ( n )
+	2 _THB! ( TH input ) ;

arch/z80/sms/blk/622

@@ -1,12 +1,10 @@
 : (spie) DROP ; ( always enabled )
 : (spix) ( x -- x, for port B )
     0 SWAP ( rx tx ) 8 0 DO
-        ( send bit 7 to bit 6, TR's output bit )
-        DUP 1 RSHIFT 0x40 AND ( rx tx bits ) 0x80 OR ( CLK hi )
-        0x3f PC@ OR 0xf3 AND ( TH and TR output )
-        DUP 0x3f PC! ( rx tx bits )
-        ( CLK low ) 0x7f AND 0x3f PC! ( rx tx )
-        ( shift tx ) 1 LSHIFT ( rx tx<< )
-        ( read into rx ) SWAP 1 LSHIFT 0xdc PC@ ( tx<< rx<< x )
+        ( send current bit to TRB, TR's output bit )
+        DUP 7 I - RSHIFT 1 AND _TRB!
+        1 _THB! ( CLK hi )
+        0 _THB! ( CLK lo )
+        ( read into rx ) SWAP 1 LSHIFT _D1@ ( tx rx<< x )
         ( out bit is the 6th ) 6 RSHIFT 1 AND OR
     SWAP LOOP ( rx tx ) DROP ;

arch/z80/sms/blk/625

@@ -0,0 +1,15 @@
+( Routines for interacting with SMS controller ports.
+  Requires CPORT_CTL, CPORT_D1 and CPORT_D2 to be defined.
+  Will usually be 0x3f, 0xdc, 0xdd. )
+( mode -- set TR pin on mode a on:
+0= output low 1=output high 2=input )
+CODE _TRA! HL POP, chkPS, ( B0 -> B4, B1 -> B0 )
+    L RR, RLA, RLA, RLA, RLA, L RR, RLA,
+    0x11 ANDi, L A LDrr, CPORT_CTL INAi,
+    0xee ANDi, L ORr, CPORT_CTL OUTiA,
+;CODE
+CODE _THA! HL POP, chkPS, ( B0 -> B5, B1 -> B1 )
+    L RR, RLA, RLA, RLA, RLA, L RR, RLA, RLA,
+    0x22 ANDi, L A LDrr, CPORT_CTL INAi,
+    0xdd ANDi, L ORr, CPORT_CTL OUTiA,
+;CODE

arch/z80/sms/blk/626

@@ -0,0 +1,12 @@
+CODE _TRB! HL POP, chkPS, ( B0 -> B6, B1 -> B2 )
+    L RR, RLA, RLA, RLA, RLA, L RR, RLA, RLA, RLA,
+    0x44 ANDi, L A LDrr, CPORT_CTL INAi,
+    0xbb ANDi, L ORr, CPORT_CTL OUTiA,
+;CODE
+CODE _THB! HL POP, chkPS, ( B0 -> B7, B1 -> B3 )
+    L RR, RLA, RLA, RLA, RLA, L RR, RLA, RLA, RLA, RLA,
+    0x88 ANDi, L A LDrr, CPORT_CTL INAi,
+    0x77 ANDi, L ORr, CPORT_CTL OUTiA,
+;CODE
+CODE _D1@ CPORT_D1 INAi, PUSHA, ;CODE
+CODE _D2@ CPORT_D2 INAi, PUSHA, ;CODE

arch/z80/sms/xcomp.fs

@@ -10,8 +10,9 @@ SYSVARS 0x70 + CONSTANT VDP_MEM
 32     CONSTANT VDP_COLS
 24     CONSTANT VDP_ROWS
 SYSVARS 0x72 + CONSTANT PAD_MEM
-0x3f   CONSTANT PAD_CTLPORT
-0xdc   CONSTANT PAD_D1PORT
+0x3f   CONSTANT CPORT_CTL
+0xdc   CONSTANT CPORT_D1
+0xdd   CONSTANT CPORT_D2
 5 LOAD  ( z80 assembler )
 : ZFILL, ( u ) 0 DO 0 A, LOOP ;
 262 LOAD  ( xcomp )
@@ -28,6 +29,7 @@ CURRENT @ XCURRENT !
 353 LOAD  ( xcomp core low )
 CREATE ~FNT CPFNT7x7
 603 608 LOADR ( VDP )
+625 626 LOADR ( SMS ports )
 612 617 LOADR ( PAD )
 390 LOAD  ( xcomp core high )
 (entry) _

arch/z80/sms/xcompkbd.fs

@@ -0,0 +1,41 @@
+( xcomp for a SMS with PS/2 keyboard on port A )
+( 8K of onboard RAM )
+0xdd00 CONSTANT RS_ADDR
+( Memory register at the end of RAM. Must not overwrite )
+0xddca CONSTANT PS_ADDR
+RS_ADDR 0x80 - CONSTANT SYSVARS
+0xc000 CONSTANT HERESTART
+SYSVARS 0x70 + CONSTANT VDP_MEM
+0xbf   CONSTANT VDP_CTLPORT
+0xbe   CONSTANT VDP_DATAPORT
+32     CONSTANT VDP_COLS
+24     CONSTANT VDP_ROWS
+SYSVARS 0x72 + CONSTANT PS2_MEM
+0x3f   CONSTANT CPORT_CTL
+0xdc   CONSTANT CPORT_D1
+0xdd   CONSTANT CPORT_D2
+5 LOAD  ( z80 assembler )
+: ZFILL, ( u ) 0 DO 0 A, LOOP ;
+262 LOAD  ( xcomp )
+524 LOAD  ( font compiler )
+282 LOAD  ( boot.z80.decl )
+270 LOAD  ( xcomp overrides )
+
+DI, 0x100 JP, 0x62 ZFILL, ( 0x66 )
+RETN, 0x98 ZFILL, ( 0x100 )
+( All set, carry on! )
+CURRENT @ XCURRENT !
+0x100 BIN( !
+283 335 LOADR ( boot.z80 )
+353 LOAD  ( xcomp core low )
+CREATE ~FNT CPFNT7x7
+603 608 LOADR ( VDP )
+625 626 LOADR ( SMS ports )
+620 LOAD ( PAD ) : (ps2kc) (ps2kcA) ; 411 414 LOADR
+390 LOAD  ( xcomp core high )
+(entry) _
+( Update LATEST )
+PC ORG @ 8 + !
+," VDP$ PS2$ (im1) " EOT,
+ORG @ 0x100 - 256 /MOD 2 PC! 2 PC!
+H@ 256 /MOD 2 PC! 2 PC!

arch/z80/sms/xcompsdc.fs

@@ -0,0 +1,44 @@
+( xcomp for a SMS with PS/2 keyboard on port A and SPI relay
+  on port B, with SD card attached )
+( 8K of onboard RAM )
+0xdd00 CONSTANT RS_ADDR
+( Memory register at the end of RAM. Must not overwrite )
+0xddca CONSTANT PS_ADDR
+RS_ADDR 0x80 - CONSTANT SYSVARS
+0xc000 CONSTANT HERESTART
+SYSVARS 0x70 + CONSTANT VDP_MEM
+0xbf   CONSTANT VDP_CTLPORT
+0xbe   CONSTANT VDP_DATAPORT
+32     CONSTANT VDP_COLS
+24     CONSTANT VDP_ROWS
+SYSVARS 0x72 + CONSTANT PS2_MEM
+0x3f   CONSTANT CPORT_CTL
+0xdc   CONSTANT CPORT_D1
+0xdd   CONSTANT CPORT_D2
+5 LOAD  ( z80 assembler )
+: ZFILL, ( u ) 0 DO 0 A, LOOP ;
+262 LOAD  ( xcomp )
+524 LOAD  ( font compiler )
+282 LOAD  ( boot.z80.decl )
+270 LOAD  ( xcomp overrides )
+
+DI, 0x100 JP, 0x62 ZFILL, ( 0x66 )
+RETN, 0x98 ZFILL, ( 0x100 )
+( All set, carry on! )
+CURRENT @ XCURRENT !
+0x100 BIN( !
+283 335 LOADR ( boot.z80 )
+353 LOAD  ( xcomp core low )
+CREATE ~FNT CPFNT7x7
+603 608 LOADR ( VDP )
+625 626 LOADR ( SMS ports )
+620 LOAD ( PAD ) : (ps2kc) (ps2kcA) ; 411 414 LOADR
+622 LOAD ( SPI )
+1 CONSTANT SDC_DEVID 423 436 LOADR ( SDC )
+390 LOAD  ( xcomp core high )
+(entry) _
+( Update LATEST )
+PC ORG @ 8 + !
+," VDP$ PS2$ BLK$ (im1) " EOT,
+ORG @ 0x100 - 256 /MOD 2 PC! 2 PC!
+H@ 256 /MOD 2 PC! 2 PC!

emul/z80/sms.c

@@ -76,6 +76,11 @@ static uint8_t iord_kbd()
     return kbd_rd(&kbd);
 }
 
+static uint8_t iord_ports_ctl()
+{
+    return ports_ctl_rd(&ports);
+}
+
 static void iowr_vdp_cmd(uint8_t val)
 {
     vdp_cmd_wr(&vdp, val);
@@ -357,7 +362,7 @@ int main(int argc, char *argv[])
     m->iord[VDP_DATA_PORT] = iord_vdp_data;
     m->iord[PORTS_IO1_PORT] = iord_ports_io1;
     m->iord[PORTS_IO2_PORT] = iord_ports_io2;
-    m->iord[PORTS_CTL_PORT] = iord_noop;
+    m->iord[PORTS_CTL_PORT] = iord_ports_ctl;
     m->iowr[VDP_CMD_PORT] = iowr_vdp_cmd;
     m->iowr[VDP_DATA_PORT] = iowr_vdp_data;
     m->iowr[PORTS_CTL_PORT] = iowr_ports_ctl;