sms: CPORT_CTL is write-only!

why did I think that I could read from it?

arch/z80/sms/blk/625

@@ -1,15 +1,16 @@
 ( Routines for interacting with SMS controller ports.
-  Requires CPORT_CTL, CPORT_D1 and CPORT_D2 to be defined.
-  Will usually be 0x3f, 0xdc, 0xdd. )
+  Requires CPORT_MEM, CPORT_CTL, CPORT_D1 and CPORT_D2 to be
+  defined. CPORT_MEM is a 1 byte buffer for CPORT_CTL. The last
+  3 consts 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,
+    0x11 ANDi, L A LDrr, CPORT_MEM LDA(i),
+    0xee ANDi, L ORr, CPORT_CTL OUTiA, CPORT_MEM LD(i)A,
 ;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,
+    0x22 ANDi, L A LDrr, CPORT_MEM LDA(i),
+    0xdd ANDi, L ORr, CPORT_CTL OUTiA, CPORT_MEM LD(i)A,
 ;CODE

arch/z80/sms/blk/626

@@ -1,12 +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,
+    0x44 ANDi, L A LDrr, CPORT_MEM LDA(i),
+    0xbb ANDi, L ORr, CPORT_CTL OUTiA, CPORT_MEM LD(i)A,
 ;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,
+    0x88 ANDi, L A LDrr, CPORT_MEM LDA(i),
+    0x77 ANDi, L ORr, CPORT_CTL OUTiA, CPORT_MEM LD(i)A,
 ;CODE
 CODE _D1@ CPORT_D1 INAi, PUSHA, ;CODE
 CODE _D2@ CPORT_D2 INAi, PUSHA, ;CODE

arch/z80/sms/xcomp.fs

@@ -9,10 +9,11 @@ SYSVARS 0x70 + CONSTANT VDP_MEM
 0xbe   CONSTANT VDP_DATAPORT
 32     CONSTANT VDP_COLS
 24     CONSTANT VDP_ROWS
-SYSVARS 0x72 + CONSTANT PAD_MEM
+SYSVARS 0x72 + CONSTANT CPORT_MEM
 0x3f   CONSTANT CPORT_CTL
 0xdc   CONSTANT CPORT_D1
 0xdd   CONSTANT CPORT_D2
+SYSVARS 0x73 + CONSTANT PAD_MEM
 5 LOAD  ( z80 assembler )
 : ZFILL, ( u ) 0 DO 0 A, LOOP ;
 262 LOAD  ( xcomp )

arch/z80/sms/xcompkbd.fs

@@ -10,10 +10,11 @@ SYSVARS 0x70 + CONSTANT VDP_MEM
 0xbe   CONSTANT VDP_DATAPORT
 32     CONSTANT VDP_COLS
 24     CONSTANT VDP_ROWS
-SYSVARS 0x72 + CONSTANT PS2_MEM
+SYSVARS 0x72 + CONSTANT CPORT_MEM
 0x3f   CONSTANT CPORT_CTL
 0xdc   CONSTANT CPORT_D1
 0xdd   CONSTANT CPORT_D2
+SYSVARS 0x73 + CONSTANT PS2_MEM
 5 LOAD  ( z80 assembler )
 : ZFILL, ( u ) 0 DO 0 A, LOOP ;
 262 LOAD  ( xcomp )

arch/z80/sms/xcompsdc.fs

@@ -11,10 +11,11 @@ SYSVARS 0x70 + CONSTANT VDP_MEM
 0xbe   CONSTANT VDP_DATAPORT
 32     CONSTANT VDP_COLS
 24     CONSTANT VDP_ROWS
-SYSVARS 0x72 + CONSTANT PS2_MEM
+SYSVARS 0x72 + CONSTANT CPORT_MEM
 0x3f   CONSTANT CPORT_CTL
 0xdc   CONSTANT CPORT_D1
 0xdd   CONSTANT CPORT_D2
+SYSVARS 0x73 + CONSTANT PS2_MEM
 5 LOAD  ( z80 assembler )
 : ZFILL, ( u ) 0 DO 0 A, LOOP ;
 262 LOAD  ( xcomp )

emul/z80/sms.c

@@ -76,11 +76,6 @@ 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);
@@ -362,7 +357,7 @@ 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_ports_ctl;
+    m->iord[PORTS_CTL_PORT] = iord_noop;
     m->iowr[VDP_CMD_PORT] = iowr_vdp_cmd;
     m->iowr[VDP_DATA_PORT] = iowr_vdp_data;
     m->iowr[PORTS_CTL_PORT] = iowr_ports_ctl;

emul/z80/sms_ports.c

@@ -9,11 +9,6 @@ void ports_init(Ports *ports)
     ports->THB = TRI_HIGHZ;
 }
 
-uint8_t ports_ctl_rd(Ports *ports)
-{
-    return ports->ctl;
-}
-
 void ports_ctl_wr(Ports *ports, uint8_t val)
 {
     ports->ctl = val;

emul/z80/sms_ports.h

@@ -15,7 +15,6 @@ typedef struct {
 } Ports;
 
 void ports_init(Ports *ports);
-uint8_t ports_ctl_rd(Ports *ports);
 void ports_ctl_wr(Ports *ports, uint8_t val);
 uint8_t ports_A_rd(Ports *ports);
 uint8_t ports_B_rd(Ports *ports);