Integrate RDLN input buffer into sysvars

In the beginning of Collapse OS' Forth version, the readline sub-
system was optional. This is why we had this separate RDLN$ routine
and that the input buffer was allocated at boot time.

It's been a while since the RDLN system has been made mandatory, but
we still paid the complexity tax of this separation. Not anymore.

arch/8086/pcat/blk.fs

@@ -75,7 +75,7 @@ CODE AT-XY ( x y )
 ( ----- 612 )
 0xff00 CONSTANT RS_ADDR
 0xfffa CONSTANT PS_ADDR
-RS_ADDR 0x80 - CONSTANT SYSVARS
+RS_ADDR 0xa0 - CONSTANT SYSVARS
 30 LOAD   ( 8086 asm )
 262 LOAD  ( xcomp ) 270 LOAD  ( xcomp overrides )
 445 461 LOADR ( 8086 boot code )

arch/z80/rc2014/blk.fs

@@ -71,7 +71,7 @@ CODE SIOB>
 ( ----- 619 )
 ( RC2014 classic with MC6850 )
 0xff00 CONSTANT RS_ADDR        0xfffa CONSTANT PS_ADDR
-RS_ADDR 0x80 - CONSTANT SYSVARS
+RS_ADDR 0xa0 - CONSTANT SYSVARS
 0x8000 CONSTANT HERESTART
 0x80 CONSTANT 6850_CTL 0x81 CONSTANT 6850_IO
 4 CONSTANT SPI_DATA 5 CONSTANT SPI_CTL 1 CONSTANT SDC_DEVID
@@ -88,7 +88,7 @@ PC ORG @ 8 + ! ( Update LATEST )
 ( ----- 620 )
 ( RC2014 classic with SIO )
 0xff00 CONSTANT RS_ADDR        0xfffa CONSTANT PS_ADDR
-RS_ADDR 0x80 - CONSTANT SYSVARS
+RS_ADDR 0xa0 - CONSTANT SYSVARS
 0x8000 CONSTANT HERESTART
 0x80 CONSTANT SIOA_CTL   0x81 CONSTANT SIOA_DATA
 0x82 CONSTANT SIOB_CTL   0x83 CONSTANT SIOB_DATA

arch/z80/sms/xcomp.fs

@@ -2,16 +2,16 @@
 0xdd00 CONSTANT RS_ADDR
 ( Memory register at the end of RAM. Must not overwrite )
 0xddca CONSTANT PS_ADDR
-RS_ADDR 0x80 - CONSTANT SYSVARS
+RS_ADDR 0xb0 - CONSTANT SYSVARS
 0xc000 CONSTANT HERESTART
 0xbf   CONSTANT TMS_CTLPORT
 0xbe   CONSTANT TMS_DATAPORT
-SYSVARS 0x70 + CONSTANT GRID_MEM
-SYSVARS 0x73 + CONSTANT CPORT_MEM
+SYSVARS 0xa0 + CONSTANT GRID_MEM
+SYSVARS 0xa3 + CONSTANT CPORT_MEM
 0x3f   CONSTANT CPORT_CTL
 0xdc   CONSTANT CPORT_D1
 0xdd   CONSTANT CPORT_D2
-SYSVARS 0x74 + CONSTANT PAD_MEM
+SYSVARS 0xa4 + CONSTANT PAD_MEM
 5 LOAD  ( z80 assembler )
 262 LOAD  ( xcomp )
 524 LOAD  ( font compiler )

arch/z80/sms/xcompkbd.fs

@@ -3,16 +3,16 @@
 0xdd00 CONSTANT RS_ADDR
 ( Memory register at the end of RAM. Must not overwrite )
 0xddca CONSTANT PS_ADDR
-RS_ADDR 0x80 - CONSTANT SYSVARS
+RS_ADDR 0xb0 - CONSTANT SYSVARS
 0xc000 CONSTANT HERESTART
 0xbf   CONSTANT TMS_CTLPORT
 0xbe   CONSTANT TMS_DATAPORT
-SYSVARS 0x70 + CONSTANT GRID_MEM
-SYSVARS 0x73 + CONSTANT CPORT_MEM
+SYSVARS 0xa0 + CONSTANT GRID_MEM
+SYSVARS 0xa3 + CONSTANT CPORT_MEM
 0x3f   CONSTANT CPORT_CTL
 0xdc   CONSTANT CPORT_D1
 0xdd   CONSTANT CPORT_D2
-SYSVARS 0x74 + CONSTANT PS2_MEM
+SYSVARS 0xa4 + CONSTANT PS2_MEM
 5 LOAD  ( z80 assembler )
 262 LOAD  ( xcomp )
 524 LOAD  ( font compiler )

arch/z80/sms/xcompsdc.fs

@@ -4,16 +4,16 @@
 0xdd00 CONSTANT RS_ADDR
 ( Memory register at the end of RAM. Must not overwrite )
 0xddca CONSTANT PS_ADDR
-RS_ADDR 0x80 - CONSTANT SYSVARS
+RS_ADDR 0xb0 - CONSTANT SYSVARS
 0xc000 CONSTANT HERESTART
 0xbf   CONSTANT TMS_CTLPORT
 0xbe   CONSTANT TMS_DATAPORT
-SYSVARS 0x70 + CONSTANT GRID_MEM
-SYSVARS 0x73 + CONSTANT CPORT_MEM
+SYSVARS 0xa0 + CONSTANT GRID_MEM
+SYSVARS 0xa3 + CONSTANT CPORT_MEM
 0x3f   CONSTANT CPORT_CTL
 0xdc   CONSTANT CPORT_D1
 0xdd   CONSTANT CPORT_D2
-SYSVARS 0x74 + CONSTANT PS2_MEM
+SYSVARS 0xa4 + CONSTANT PS2_MEM
 5 LOAD  ( z80 assembler )
 262 LOAD  ( xcomp )
 524 LOAD  ( font compiler )

arch/z80/sms/xcomptextmode.fs

@@ -4,16 +4,16 @@
 0xdd00 CONSTANT RS_ADDR
 ( Memory register at the end of RAM. Must not overwrite )
 0xddca CONSTANT PS_ADDR
-RS_ADDR 0x80 - CONSTANT SYSVARS
+RS_ADDR 0xb0 - CONSTANT SYSVARS
 0xc000 CONSTANT HERESTART
 0xbf   CONSTANT TMS_CTLPORT
 0xbe   CONSTANT TMS_DATAPORT
-SYSVARS 0x70 + CONSTANT GRID_MEM
-SYSVARS 0x73 + CONSTANT CPORT_MEM
+SYSVARS 0xa0 + CONSTANT GRID_MEM
+SYSVARS 0xa3 + CONSTANT CPORT_MEM
 0x3f   CONSTANT CPORT_CTL
 0xdc   CONSTANT CPORT_D1
 0xdd   CONSTANT CPORT_D2
-SYSVARS 0x74 + CONSTANT PS2_MEM
+SYSVARS 0xa4 + CONSTANT PS2_MEM
 5 LOAD  ( z80 assembler )
 262 LOAD  ( xcomp )
 523 LOAD  ( font compiler )

arch/z80/ti84/xcomp.fs

@@ -1,10 +1,10 @@
 0xbf00 CONSTANT RS_ADDR
 0xbffa CONSTANT PS_ADDR
-RS_ADDR 0x80 - CONSTANT SYSVARS
+RS_ADDR 0xb0 - CONSTANT SYSVARS
 0x8000 CONSTANT HERESTART
-SYSVARS 0x70 + CONSTANT LCD_MEM
-SYSVARS 0x72 + CONSTANT GRID_MEM
-SYSVARS 0x75 + CONSTANT KBD_MEM
+SYSVARS 0xa0 + CONSTANT LCD_MEM
+SYSVARS 0xa2 + CONSTANT GRID_MEM
+SYSVARS 0xa5 + CONSTANT KBD_MEM
 0x01 CONSTANT KBD_PORT
 5 LOAD  ( z80 assembler )
 262 LOAD  ( xcomp )

arch/z80/trs80/xcomp.fs

@@ -1,6 +1,6 @@
 0xff00 CONSTANT RS_ADDR
 0xfffa CONSTANT PS_ADDR
-RS_ADDR 0x80 - CONSTANT SYSVARS
+RS_ADDR 0xa0 - CONSTANT SYSVARS
 0 CONSTANT HERESTART
 5 LOAD   ( z80 assembler )
 262 LOAD ( xcomp )

arch/z80/z80mbc2/xcomp.fs

@@ -1,5 +1,5 @@
 0xff00 CONSTANT RS_ADDR        0xfffa CONSTANT PS_ADDR
-RS_ADDR 0x80 - CONSTANT SYSVARS
+RS_ADDR 0xa0 - CONSTANT SYSVARS
 0 CONSTANT HERESTART
 5 LOAD    ( z80 assembler )
 262 LOAD  ( xcomp )

blk.fs

@@ -1682,14 +1682,13 @@ with "390 LOAD"
 : H@ HERE @ ;
 : FIND ( w -- a f ) CURRENT @ SWAP _find ;
 : IN> 0x30 RAM+ ; ( current position in INBUF )
-: IN( 0x32 RAM+ @ ; ( points to INBUF )
-: IN) 0x40 ( buffer size ) IN( + ; ( INBUF's end )
+: IN( 0x60 RAM+ ; ( points to INBUF )
 : IN$ 0 IN( DUP IN> ! ! ; ( flush input buffer )
 : QUIT
     (resRS) 0 0x08 RAM+ ! ( C<* override ) IN$
     LIT" (main)" FIND DROP EXECUTE
 ;
-1 33 LOADR+
+1 31 LOADR+
 ( ----- 354 )
 : ABORT (resSP) QUIT ;
 : = CMP NOT ; : < CMP -1 = ; : > CMP 1 = ;
@@ -1978,7 +1977,7 @@ SYSVARS 0x55 + :** KEY?
 : RDLN ( Read 1 line in input buff and make IN> point to it )
     IN$ BEGIN
     ( buffer overflow? same as if we typed a newline )
-    IN> @ IN) 1- = IF CR ELSE KEY THEN ( c )
+    IN> @ IN( - 0x3e = IF CR ELSE KEY THEN ( c )
     DUP BS? IF
         IN> @ IN( > IF -1 IN> +! BS EMIT THEN SPC> BS EMIT
     ELSE DUP LF = IF DROP CR THEN ( same as CR )
@@ -1996,13 +1995,6 @@ SYSVARS 0x55 + :** KEY?
     ( update C<? flag )
     IN> @ C@ 0 > 0x06 RAM+ !  ( 06 == C<? ) ;
 ( ----- 381 )
-( Initializes the readln subsystem )
-: RDLN$
-    H@ 0x32 ( IN(* ) RAM+ !
-    IN) IN( - ALLOT IN$
-    ['] RDLN< ['] C<* **!
-    1 0x06 RAM+ !  ( 06 == C<? ) ;
-( ----- 382 )
 : LIST
     BLK@
     16 0 DO
@@ -2012,7 +2004,7 @@ SYSVARS 0x55 + :** KEY?
         LOOP
         NL>
     LOOP ;
-( ----- 383 )
+( ----- 382 )
 : INTERPRET
     BEGIN
     WORD DUP @ 0x0401 = ( EOT ) IF DROP EXIT THEN
@@ -2028,7 +2020,7 @@ SYSVARS 0x55 + :** KEY?
   is to check whether we're restoring to "_", the word above.
   if yes, then we're in a nested load. Also, the 1 in 0x06 is
   to avoid tons of "ok" displays. )
-( ----- 384 )
+( ----- 383 )
 : LOAD
     BLK> @ >R ( save restorable variables to RSP )
     0x08 RAM+ @ >R  ( 08 == C<* override )
@@ -2045,7 +2037,7 @@ SYSVARS 0x55 + :** KEY?
     ELSE ( not nested )
         R> 0x08 RAM+ ! R> DROP ( BLK> )
     THEN ;
-( ----- 385 )
+( ----- 384 )
 : LOAD+ BLK> @ + LOAD ;
 ( b1 b2 -- )
 : LOADR 1+ SWAP DO I DUP . SPC> LOAD LOOP ;
@@ -2062,7 +2054,8 @@ SYSVARS 0x55 + :** KEY?
     ['] (boot<) ['] C<* **!
     ( boot< always has a char waiting. 06 == C<?* )
     1 0x06 RAM+ ! INTERPRET
-    RDLN$ LIT" _sys" [entry]
+    ['] RDLN< ['] C<* **! IN$
+    LIT" _sys" [entry]
     LIT" Collapse OS" STYPE NL> (main) ;
 XCURRENT @ _xapply ORG @ 0x04 ( stable ABI BOOT ) + !
 1 4 LOADR+

cvm/common.fs

@@ -2,7 +2,7 @@
   binaries. )
 0xff00 CONSTANT RS_ADDR
 0xfffa CONSTANT PS_ADDR
-RS_ADDR 0x80 - CONSTANT SYSVARS
+RS_ADDR 0xb0 - CONSTANT SYSVARS
 0 CONSTANT HERESTART
 : CODE ( natidx -- ) (entry) 0 C, C, ;
 VARIABLE ORG

cvm/forth.fs

@@ -3,7 +3,7 @@
     DROP COLS /MOD 6 PC! ( y ) 5 PC! ( x ) ;
 : CELL! ( c pos -- ) 0 CURSOR! 0 PC! ;
 
-SYSVARS 0x70 + CONSTANT GRID_MEM
+SYSVARS 0xa0 + CONSTANT GRID_MEM
 402 403 LOADR ( Grid )
 390 LOAD  ( xcomp core high )
 (entry) _

cvm/vm.h

@@ -3,7 +3,7 @@
 
 #define SP_ADDR 0xffff
 #define RS_ADDR 0xff00
-#define SYSVARS RS_ADDR-0x80
+#define SYSVARS RS_ADDR-0xb0
 #define MEMSIZE 0x10000
 
 typedef uint8_t byte;

doc/hw/z80/ps2.txt

@@ -68,7 +68,7 @@ First, we need a "(ps2kc)" routine (see doc/protocol.txt). In
 this case, it's easy, it's ": (ps2kc) 8 PC@ ;". Then, we can
 load PS/2 subsystem. You add "411 414 LOADR". Then, at
 initialization, you add "PS2$".  You also need to define PS2_MEM
-at the top. You can probably use "SYSVARS + 0x7a".
+at the top. You can probably use "SYSVARS + 0xaa".
 
 The PS/2 subsystem provides "(key)" from "(ps2kc)".
 

doc/hw/z80/sms/ps2.txt

@@ -113,7 +113,7 @@ it with /cvm/avra.sh.
 
 We start with the base SMS xcomp and add a few things:
 
-1. at the top: "SYSVARS 0x72 + CONSTANT PS2_MEM"
+1. at the top: "SYSVARS 0xa2 + CONSTANT PS2_MEM"
 2. After VDP load: "621 LOAD : (ps2kc) (ps2kcB) ;" (that binds
    us to port B)
 3. Right after: "411 414 LOADR" (that gives us "(key)")

doc/impl.txt

@@ -153,6 +153,9 @@ fact, they're mostly referred to directly as their numerical
 offset along with a comment indicating what this offset refers
 to.
 
+SYSVARS occupy 0xa0 bytes in memory in addition to driver mem-
+ory, which typically follows SYSVARS.
+
 This system is a bit fragile because every time we change those
 offsets, we have to be careful to adjust all system variables
 offsets, but thankfully, there aren't many system variables.
@@ -167,9 +170,8 @@ SYSVARS   FUTURE USES          +3c       BLK(*
 +0c       C<*                  +53       EMIT ialias
 +0e       WORDBUF              +55       KEY? ialias
 +2e       BOOT C< PTR          +57       FUTURE USES
-+30       IN>
-+32       IN(*                 +70       DRIVERS
-+34       BLK@*                +80       RAMEND
++30       IN>                  +60       INPUT BUFFER
++32       FUTURE USES          +a0       DRIVERS
 +36       BLK!*
 +38       BLK>
 +3a       BLKDTY

emul/8086/xcomp.fs

@@ -1,6 +1,6 @@
 0xff00 CONSTANT RS_ADDR
 0xfffa CONSTANT PS_ADDR
-RS_ADDR 0x80 - CONSTANT SYSVARS
+RS_ADDR 0xa0 - CONSTANT SYSVARS
 30 LOAD   ( 8086 asm )
 262 LOAD  ( xcomp ) 270 LOAD  ( xcomp overrides )
 445 461 LOADR ( 8086 boot code )

emul/z80/xcomp.fs

@@ -1,6 +1,6 @@
 0xff00 CONSTANT RS_ADDR
 0xfffa CONSTANT PS_ADDR
-RS_ADDR 0x80 - CONSTANT SYSVARS
+RS_ADDR 0xa0 - CONSTANT SYSVARS
 0 CONSTANT HERESTART
 5 LOAD  ( z80 assembler )
 262 LOAD  ( xcomp )