forth: remove RAMSTART and RS_ADDR from stable ABI

emul/Makefile

@@ -104,7 +104,7 @@ updatebootstrap: $(ZASMBIN)
 .PHONY: fbootstrap
 fbootstrap: forth/stage2
 	cat ./forth/conf.fs ../forth/boot.fs | ./forth/stage2 > forth/boot.bin
-	cat ../forth/z80c.fs forth/emul.fs ../forth/icore.fs | ./forth/stage2 | tee forth/z80c.bin > /dev/null
+	cat ./forth/conf.fs ../forth/z80c.fs forth/emul.fs ../forth/icore.fs | ./forth/stage2 | tee forth/z80c.bin > /dev/null
 
 .PHONY: clean
 clean:

forth/boot.fs

@@ -25,11 +25,11 @@ JP(IY), NOP,      ( 17, nativeWord )
 0 JPnn,           ( 1d, chkPS )
 NOP, NOP,         ( 20, numberWord )
 NOP, NOP,         ( 22, litWord )
-RAMSTART ,        ( 24, RAMSTART )
+NOP, NOP,         ( 24, unused )
 NOP, NOP,         ( 26, unused )
 0 JPnn,           ( 28, flagsToBC )
 0 JPnn,           ( 2b, doesWord )
-RS_ADDR ,         ( 2e, RS_ADDR )
+NOP, NOP,         ( 2e, unused )
 NOP, NOP,         ( 30, unused )
 NOP, NOP,         ( 32, unused )
 NOP, NOP,         ( 34, unused )

forth/z80c.fs

@@ -18,6 +18,8 @@
 
   Oh, also: KEY and EMIT are not defined here. There're
   expected to be defined in platform-specific code.
+
+  This unit expects the same conf as boot.fs.
 )
 
 ( dummy entry for dict hook )
@@ -333,13 +335,12 @@ CODE BYE
 ;CODE
 
 CODE (resSP)
-    ( INITIAL_SP == 36 )
+    ( INITIAL_SP == RAM+0 )
-    SP 36 @ LDdd(nn),
+    SP RAMSTART LDdd(nn),
 ;CODE
 
 CODE (resRS)
-    ( RS_ADDR == 46 )
+    IX RS_ADDR LDddnn,
-    IX 46 @ LDddnn,
 ;CODE
 
 CODE SCMP