Relay-Version: version B 2.10.3 alpha 4/15/85; site seismo.UUCP Posting-Version: version B 2.10.2 9/3/84; site genrad.UUCP Path: seismo!harvard!talcott!panda!genrad!sources-request From: sources-request@genrad.UUCP Newsgroups: mod.sources Subject: C Forth (Part 2 of 3) Message-ID: <868@genrad.UUCP> Date: 24 May 85 14:11:07 GMT Sender: john@genrad.UUCP Lines: 2593 Approved: john@genrad.UUCP This is posting two of three of a portable FORTH interpreter, written entirely in C. It has been successfully ported to a VAX 11/60 running BSD 2.9, to EUNICE version 3 (I think), and the original machine, a VAX 11/780 running BSD 4.2. When I mentioned in net.lang.forth (and elsewhere) that I was writing this portable FORTH, several people asked that I post the results of my labors. Well, here they are. -- Allan Pratt (after May 7:) APRATT.PA@XEROX.ARPA [moderator's note: I have had no luck at all getting through to this address. There was a missing file in the original distribution: "forth.lex.h" which I have reconstructed (hopefully correctly). - John P. Nelson] ------------- cut here ---------------- : Run this shell script with "sh" not "csh" PATH=:/bin:/usr/bin:/usr/ucb export PATH echo 'x - Makefile' sed 's/^X//' <<'//go.sysin dd *' >Makefile test: forth.core forth forth: forth.o prims.o cc -o forth forth.o prims.o forth.o: forth.c common.h forth.h prims.h cc -c forth.c prims.o: prims.c forth.h prims.h cc -c prims.c all: forth forth.core l2b b2l nf: nf.o lex.yy.o cc -o nf nf.o lex.yy.o nf.o: nf.c forth.lex.h common.h cc -c nf.c lex.yy.o: lex.yy.c forth.lex.h cc -c lex.yy.c lex.yy.c: forth.lex lex forth.lex rm -f lex.tmp sed "s/yylex(){/TOKEN *yylex(){/" lex.yy.c > lex.tmp mv -f lex.tmp lex.yy.c forth.core: nf forth.dict nf < forth.dict # l2b: convert a line file to a block file. Usage: l2b < linefile > blockfile l2b: l2b.c cc -o l2b l2b.c # b2l: convert a block file to a line file. Usage: b2l < blockfile > linefile b2l: b2l.c cc -o b2l b2l.c # forth.line and forth.block are not included here, because you can't tell # which one is more recent. To make one from the other, use b2l and l2b. //go.sysin dd * echo 'x - b2l.c' sed 's/^X//' <<'//go.sysin dd *' >b2l.c X/* usage: block2line < blockfile > linefile * takes a block file from stdin and makes a cr-delimited file to stdout * with 64 characters per line, 16 lines per screen */ #include main() { int i, j, screen; char buf[64]; /* max line size */ while(1) { printf("------------------ SCREEN %d ------------------\n", screen++); for (i=0; i<16; i++) { if (fread(buf,sizeof(char),64,stdin) < 64) exit(0); j = 63; while (buf[j] == ' ' && j >= 0) j--; if (j >= 0) fwrite(buf,sizeof(char),j+1,stdout); putchar('\n'); } } } //go.sysin dd * echo 'x - common.h' sed 's/^X//' <<'//go.sysin dd *' >common.h X/* * This is common.h -- the defines which are common to both nf.c and forth.c. * These include the name of the SAVEFILE (the file which nf.c creates, * and the default image which f.c loads), and all those boundaries for * memory areas, like UP, USER_DEFAULTS, etc. */ X/* * NOTE THAT THIS FORTH IMPLENTATION REQUIRES int TO BE TWICE THE SIZE OF short */ #define TRUE 1 #define FALSE 0 X/* TWEAKING: define TRACE to allow tracing, BREAKPOINT to allow breakpoints. Each of these takes up time in the inner interpreter, so if you are not debugging, take them out. Without TRACE, the DOTRACE primitive will still work, but the TRON primitive will have no effect. */ #define TRACE #define BREAKPOINT X/* external files */ #define COREFILE "forth.core" /* used for input to f.c, output from nf.c */ #define DICTFILE "forth.dict" /* used for input to nf.c */ #define MAPFILE "forth.map" /* used for dump-output from nf.c */ #define DUMPFILE "forth.dump" /* used for dump-output from f.c */ #define BLOCKFILE "forth.block" /* used for block i/o */ #define SAVEFILE "forth.newcore" /* used by (SAVE) primitive */ X/* MEMORY ALLOCATION CONSTANTS */ X/* Set INITMEM to the size of the largest FORTH model you want nf to create. This can be just barely enough (within GULPFRQ words) to hold the initial FORTH image, or it can be the maximum size you will ever want. Somewhere in between is best, so you don't fragment memory with realloc() calls right away. */ #define INITMEM (13*1024) /* 13K holds the distribution forth.dict */ X/* set MAXMEM to the MOST MEMORY YOU EVER WANT ALLOCATED TO FORTH. FORTH will never allocate more than MAXMEM*sizeof(short) for the FORTH memory image. Note that other functions, like open, read, and write, allocate memory transparent to the forth system. MAXMEM will not affect these. Also, note that realloc is used to grow the FORTH image, and LARGE CHUNKS of fragmented memory can result. If you want to keep a tight rein on things, set MAXMEM to the same number as INITMEM, and the FORTH memory image will be fixed at that many SHORTs, with no later allocations, and therefore no fragmenting. A value of 0 for MAXMEM means "allocate as much as you want" -- useful on virtual-memory machines. Also note that each malloc and realloc is checked for success (of course), so MAXMEM is truly a maximal limit. NOTE THAT MODELS OF GREATER THAN 32K MAY CRASH BECAUSE OF SIGNED VALUES. THIS HAS NOT BEEN ADEQUATELY TESTED. */ #define MAXMEM 0 X/* set NSCR to the number of disk blocks from you want to keep in FORTH memory at any time. If your disks are fast enough, you might want a low number like 3. If you have lots of memory, you might want something like 10. In any case, this number MUST BE AT LEAST 2. */ #define NSCR 5 /* MUST BE AT LEAST 2 */ X/* end of implementation-dependent DEFINEs. */ X/* define bits for the first byte of each word */ #define MSB 0x80 /* says this is first byte */ #define IMMEDIATE 0x40 /* Says this word is immediate */ #define SMUDGE 0x20 /* on = you can't find this word */ #define MAXWIDTH 0x20 /* Maximum length of a word */ #define KBBUFF 1024 /* one disk-quantum */ #define US 32 /* words needed for user variables */ #define CO (KBBUFF+4) /* size of a disk buffer w/4 words overhead */ #define NBUF NSCR /* number of disk buffers, at 1 to a screen */ X/* Memory Management boundaries -- each name refers to the FIRST location of the indicated field Some fields are nested, and I have tried to show the nesting nature in the defines. */ #define ORIGIN 0 /* the Origin of this system is zero */ #define ORIG ORIGIN /* another word for ORIGIN */ #define SCRATCHSIZE 16 /* From ORIGIN to ORIGIN+SCRATCHSIZE is scratch space which is saved across saves: see the definition of this space below */ #define USER_DEFAULTS (ORIGIN+SCRATCHSIZE) /* 16 */ /* start of user variable initial-values space -- it's DEFS-SIZE bytes long */ #define DEFS_SIZE 8 /* words in the USER DEFAULTS area */ #define UP (USER_DEFAULTS+DEFS_SIZE) /* User var space, US bytes long */ #define TIB_START (UP+US) /* Terminal input buffer, same size as a disk buffer (KBBUFF words), starts after user variables */ #define TIB_END (TIB_START + KBBUFF) #define CS_SIZE 128 /* words in the Computation Stack */ #define RS_SIZE 256 /* words in the Return Stack */ #define INITS0 (TIB_START+KBBUFF+CS_SIZE) /* c. stack grows down CSS words, bangs into end of TIB */ #define INITR0 (INITS0+RS_SIZE) /* Return stack grows down RSS words, bangs into INITS0. */ #define BUF1 INITR0 /* buffers start right after r. stack */ #define DPBASE (BUF1+(NBUF*CO)) /* Dictionary starts just past last buffer */ X/* low-core definitions */ #define LIMIT 0 /* mem[LIMIT] tells the size of core */ #define COLDIP 1 /* mem[COLDIP] holds the CFA of ABORT */ /* you can set ip=mem[COLDIP] and call next() to start */ X/* these locations define the warm-start machine state: if you save the FORTH memory image, then restart it, execution will start up with these values. This save/restore system is not implemented, so leave mem[SAVEDIP] = 0. */ #define SAVEDIP 2 /* mem[SAVEDIP] = 0 for newly-generated systems, or the IP for a saved system */ #define SAVEDSP 3 /* restored when SAVEDIP != 0 */ #define SAVEDRP 4 /* ditto */ #define ABORTIP 5 /* need this to recover from ^C */ //go.sysin dd * echo 'x - forth.c' sed 's/^X//' <<'//go.sysin dd *' >forth.c X/* * forth.c * * Portable FORTH interpreter in C * * Author: Allan Pratt, Indiana University (iuvax!apratt) * Spring, 1984 * References: 8080 and 6502 fig-FORTH source listings (not the greatest refs * in the world...) * * This program is intended to be compact, portable, and pretty complete. * It is also intended to be in the public domain, and distribution should * include this notice to that effect. * * This file contains the support code for all interpreter functions. * the file prims.c contains code for the C-coded primitives, and the * file forth.h connects the two with definitions. * * The program nf.c generates a new forth.core file from the dictionary * forth.dict, using common.h to tie it together with this program. */ #include #include #include /* only for isxdigit */ #include "common.h" #include "forth.h" #include "prims.h" /* macro-defined primitives */ X/* declare globals which are defined in forth.h */ unsigned short csp, rsp, ip, w; short *mem; int trace, tracedepth, debug, breakenable, breakpoint, qtermflag, forceip; int nobuf; XFILE *blockfile; long bfilesize; char *bfilename; /* block file name (change with -f ) */ char *cfilename; /* core file name (change with -l ) */ char *sfilename; /* save file name (change with -s ) */ X/* ---------------------------------------------------- SYSTEM FUNCTIONS ---------------------------------------------------- */ errexit(s,p1,p2) /* An error occurred -- clean up (?) and exit. */ { printf(s,p1,p2); printf("ABORT FORTH!\nDumping to %s... ",DUMPFILE); fflush(stdout); memdump(); puts("done."); exit(1); } Callot (n) /* allot n words in the dictionary */ short n; { unsigned newsize; mem[DP] += n; /* move DP */ if (mem[DP] + GULPFRQ > mem[LIMIT]) { /* need space */ newsize = mem[DP] + GULPSIZE; if (newsize > MAXMEM && MAXMEM) errexit("ATTEMPT TO GROW PAST MAXMEM (%d) WORDS\n",MAXMEM); mem = (short *)realloc((char *)mem, newsize*sizeof(*mem)); if (mem == NULL) errexit("REALLOC FAILED\n"); mem[LIMIT] = newsize; } } push(v) /* push value v to cstack */ short v; { if (csp <= TIB_END) errexit("PUSH TO FULL CALC. STACK\n"); mem[--csp] = v; } short pop() /* pop a value from comp. stack, and return it as the value of the function */ { if (csp >= INITS0) { puts("Empty Stack!"); return 0; } return (mem[csp++]); } rpush(v) short v; { if (rsp <= INITS0) errexit("PUSH TO FULL RETURN STACK"); mem[--rsp] = v; } short rpop() { if (rsp >= INITR0) errexit("POP FROM EMPTY RETURN STACK!"); return (mem[rsp++]); } pkey() /* (KEY) -- wait for a key & return it */ { int c; if ((c = getchar()) == EOF) errexit("END-OF-FILE ENCOUNTERED"); return(c); } pqterm() /* (?TERMINAL): return true if BREAK has been hit */ { if (qtermflag) { push(TRUE); qtermflag = FALSE; /* this influences ^C handling */ } else push(FALSE); } pemit() /* (EMIT): c -- emit a character */ { putchar(pop() & 0x7f); /* stdout is unbuffered */ } next() /* instruction processor: control goes here almost right away, and cycles through here until you leave. */ X/* * This is the big kabloona. What it does is load the value at mem[ip] * into w, increment ip, and invoke prim. number w. This implies that * mem[ip] is the CFA of a word. What's in the CF of a word is the number * of the primitive which should be executed. For a word written in FORTH, * that primitive is "docol", which pushes ip to the return stack, then * uses w+2 (the PFA of the word) as the new ip. See "interp.doc" for * more. */ X/* * There is an incredible hack going on here: the SPECIAL CASE mentioned in * the code is for the word EXECUTE, which must set W itself and jump INSIDE * the "next" loop, by-passing the first instruction. This has been made a * special case: if the primitive to execute is zero, the special case is * invoked, and the code for EXECUTE is put right in the NEXT loop. For this * reason, "EXECUTE" MUST BE THE FIRST WORD IN THE DICTIONARY. */ { short p; while (1) { if (forceip) { /* force ip to this value -- used by sig_int */ ip = forceip; forceip = FALSE; } #ifdef TRACE if (trace) dotrace(); #endif TRACE #ifdef BREAKPOINT if (breakenable && ip == breakpoint) dobreak(); #endif BREAKPOINT w = mem[ip]; ip++; /* w, mem, and ip are all global. W is now a POINTER TO the primitive number to execute, and ip points to the NEXT thread to follow. */ next1: /* This is for the SPECIAL CASE */ p = mem[w]; /* p is the actual number of the primitive */ if (p == 0) { /* SPECIAL CASE FOR EXECUTE! */ w = pop(); /* see above for explanation */ goto next1; } /* else */ switch(p) { case LIT : lit(); break; case BRANCH : branch(); break; case ZBRANCH : zbranch(); break; case PLOOP : ploop(); break; case PPLOOP : pploop(); break; case PDO : pdo(); break; case I : i(); break; case R : r(); break; case DIGIT : digit(); break; case PFIND : pfind(); break; case ENCLOSE : enclose(); break; case KEY : key(); break; case PEMIT : pemit(); break; case QTERMINAL : qterminal(); break; case CMOVE : cmove(); break; case USTAR : ustar(); break; case USLASH : uslash(); break; case AND : and(); break; case OR : or(); break; case XOR : xor(); break; case SPFETCH : spfetch(); break; case SPSTORE : spstore(); break; case RPFETCH : rpfetch(); break; case RPSTORE : rpstore(); break; case SEMIS : semis(); break; case LEAVE : leave(); break; case TOR : tor(); break; case FROMR : fromr(); break; case ZEQ : zeq(); break; case ZLESS : zless(); break; case PLUS : plus(); break; case DPLUS : dplus(); break; case MINUS : minus(); break; case DMINUS : dminus(); break; case OVER : over(); break; case DROP : drop(); break; case SWAP : swap(); break; case DUP : dup(); break; case TDUP : tdup(); break; case PSTORE : pstore(); break; case TOGGLE : toggle(); break; case FETCH : fetch(); break; case CFETCH : cfetch(); break; case TFETCH : tfetch(); break; case STORE : store(); break; case CSTORE : cstore(); break; case TSTORE : tstore(); break; case DOCOL : docol(); break; case DOCON : docon(); break; case DOVAR : dovar(); break; case DOUSE : douse(); break; case SUBTRACT : subtract(); break; case EQUAL : equal(); break; case NOTEQ : noteq(); break; case LESS : less(); break; case ROT : rot(); break; case DODOES : dodoes(); break; case DOVOC : dovoc(); break; case ALLOT : allot(); break; case PBYE : pbye(); break; case TRON : tron(); break; case TROFF : troff(); break; case DOTRACE : dotrace(); break; case PRSLW : prslw(); break; case PSAVE : psave(); break; case PCOLD : pcold(); break; default : errexit("Bad execute-code %d\n",p); break; } } } dotrace() { short worka, workb, workc; putchar('\n'); if (tracedepth) { /* show any stack? */ printf("sp: %04x (", csp); worka = csp; for (workb = tracedepth; workb; workb--) printf("%04x ",(unsigned short) mem[worka++]); putchar(')'); } printf(" ip=%04x ",ip); if (mem[R0]-rsp < RS_SIZE && mem[R0] - rsp > 0) /* if legal rsp */ for (worka = mem[R0]-rsp; worka; worka--) { /* indent */ putchar('>'); putchar(' '); } worka = mem[ip] - 3; /* this is second-to-last letter, or the count byte */ while (!(mem[worka] & 0x80)) worka--; /* skip back to count byte */ workc = mem[worka] & 0x2f; /* workc is count value */ worka++; while (workc--) putchar(mem[worka++] & 0x7f); fflush(stdout); if (debug) { /* wait for \n -- any other input will dump */ char buffer[10]; if (*gets(buffer) != '\0') { printf("dumping core... "); fflush(stdout); memdump(); puts("done."); } } } #ifdef BREAKPOINT dobreak() { int temp; puts("Breakpoint."); printf("Stack pointer = %x:\n",csp); for (temp = csp; temp < INITS0; temp++) printf("\t%04x",mem[temp]); putchar('\n'); } #endif BREAKPOINT main(argc,argv) int argc; char *argv[]; { FILE *fp; unsigned short size; int i = 1; cfilename = COREFILE; /* "forth.core" */ bfilename = BLOCKFILE; /* "forth.block" */ sfilename = SAVEFILE; /* "forth.newcore" */ trace = debug = breakenable = nobuf = 0; while (i < argc) { if (*argv[i] == '-') { switch (*(argv[i]+1)) { #ifdef TRACE case 'd': /* -d[n] */ debug = 1; /* ...and fall through */ case 't': /* -t[n] */ trace = TRUE; if (argv[i][2]) tracedepth = (argv[i][2] - '0'); else tracedepth = 0; break; #else !TRACE case 'd': case 't': fprintf(stderr, "Must compile with TRACE defined for -t or -d\n"); break; #endif TRACE case 'c': if (++i == argc) usage(argv[0]); cfilename = argv[i]; /* -c file */ break; case 's': if (++i == argc) usage(argv[0]); sfilename = argv[i]; /* -s file */ break; #ifdef BREAKPOINT case 'p': if (++i == argc) usage(argv[0]); breakenable = TRUE; /* -p xxxx */ breakpoint = xtoi(argv[i]); break; #else !BREAKPOINT case 'p': fprintf(stderr, "Must compile with BREAKPOINT defined for -p"); break; #endif BREAKPOINT case 'b': if (++i == argc) usage(); bfilename = argv[i]; /* -b blockfile */ break; case 'n': nobuf = TRUE; break; default: usage(argv[0]); exit(1); } } else usage(argv[0]); /* not a dash */ i++; } if ((fp = fopen(cfilename,"r")) == NULL) { fprintf(stderr,"Forth: Could not open %s\n", cfilename); exit(1); } if (fread(&size, sizeof(size), 1, fp) != 1) { fprintf(stderr,"Forth: %s is empty.\n",cfilename); exit(1) ; } if ((mem = (short *)calloc(size, sizeof(*mem))) == NULL) { fprintf(stderr, "Forth: unable to malloc(%d,%d)\n", size, sizeof(*mem)); exit(1); } mem[LIMIT] = size; if (fread(mem+1, sizeof(*mem), size-1, fp) != size-1) { fprintf(stderr, "Forth: not %d bytes on %s.\n", size, cfilename); exit(1); } fclose(fp); initsignals(); getblockfile(); if (!nobuf) setbuf(stdout,NULL); if (ip = mem[SAVEDIP]) { /* if savedip != 0, that is */ csp = mem[SAVEDSP]; rsp = mem[SAVEDRP]; puts("restarting a saved FORTH image"); } else { ip = mem[COLDIP]; /* this is the ip passed from nf.c */ /* ip now points to a word holding the CFA of COLD */ rsp = INITR0; /* initialize return stack */ csp = INITS0; } next(); /* never returns */ } usage(s) char *s; { fprintf(stderr, "usage:\n"); fprintf(stderr, "%s [-t[n]] [-d[n]] [-p xxxx] [-n]\n",s); fputs(stderr, "\t[-c corename] [-b blockname] [-s savename]\n"); fputs(stderr, "Where:\n"); fputs(stderr, "-t[n]\t\tsets trace mode\n"); fputs(stderr, "-d[n]\t\tsets trace mode and debug mode (waits for newline)"); fputs(stderr, "\t\t[n] above sets stack depth to display. Single digit, 0-9. Default 0.\n"); fputs(stderr, "-p xxxx\t\tsets a breakpoint at xxxx (in hex), shows stack when reached\n"); fputs(stderr, "-n\t\tleaves stdout line-buffered\n"); fprintf(stderr, "-c corename\tuses corename as the core image (default %s without -c)\n", COREFILE); fprintf(stderr, "-b blockname\tuses blockname as the blockfile (default %s without -b)\n", BLOCKFILE); fprintf(stderr, "-s savename\tuses savename as the save-image file (default %s without -s)\n", SAVEFILE); } memdump() /* dump core. */ { int i; /* top of RAM */ int temp, tempb, firstzero, nonzero; char chars[9], outline[80], tstr[6]; FILE *dumpfile; dumpfile = fopen(DUMPFILE,"w"); fprintf(dumpfile, "CSP = 0x%x RSP = 0x%x IP = 0x%x W = 0x%x DP = 0x%x\n", csp, rsp, ip, w, mem[DP]); for (temp = 0; temp < mem[LIMIT]; temp += 8) { nonzero = FALSE; sprintf(outline, "%04x:", temp); for (i=temp; i= ' ') chars[i%8] = tempb; else chars[i%8] = '.'; nonzero |= mem[i]; } if (nonzero) { fprintf(dumpfile,"%s %s\n",outline,chars); firstzero = TRUE; } else if (firstzero) { fprintf(dumpfile, "----- ZERO ----\n"); firstzero = FALSE; } } fclose(dumpfile); } X/* here is where ctype.h is used */ xtoi(s) char *s; { /* convert hex ascii to integer */ int temp = 0; while (isxdigit (*s)) { /* first non-hex char ends */ temp <<= 4; /* mul by 16 */ if (isupper (*s)) temp += (*s - 'A') + 10; else if (islower (*s)) temp += (*s - 'a') + 10; else temp += (*s - '0'); s++; } return temp; } X/* * Interrupt (^C) handling: If the user hits ^C once, the next pqterm call * will return TRUE. If he hits ^C again before pqterm is called, there will * be a forced jump to ABORT next time we hit next(). If it is a primitive * that is caught in an infinite loop, this won't help any. */ sig_int() { if (qtermflag) { /* second time? */ forceip = mem[ABORTIP]; /* checked each time through next */ qtermflag = FALSE; trace = FALSE; /* stop tracing; reset */ } else qtermflag = TRUE; } initsignals() { signal(SIGINT,sig_int); } getblockfile() { /* recall that opening with mode "a+" opens for reading and writing */ /* with the pointer positioned at the end; this is so ftell returns */ /* the size of the file. */ if ((blockfile = fopen(bfilename, "a+")) == NULL) errexit("Can't open blockfile \"%s\"\n", bfilename); bfilesize = ftell(blockfile); printf("Block file has %d blocks.\n",(int) (bfilesize/1024) - 1); } //go.sysin dd * echo 'x - forth.dict' sed 's/^X//' <<'//go.sysin dd *' >forth.dict PRIM EXECUTE 0 ( cfa -- ) PRIM LIT 1 ( push the next value to the stack ) PRIM BRANCH 2 ( branch by offset in next word ) PRIM 0BRANCH 3 ( branch if zero by off. in next word ) PRIM (LOOP) 4 ( end of a ) PRIM (+LOOP) 5 ( inc -- w/increment != 1 ) PRIM (DO) 6 ( limit init -- ) PRIM I 7 ( get loop index ) PRIM DIGIT 8 ( c -- DIGIT 1 | 0 ) PRIM (FIND) 9 ( s -- s 0 | s NFA 1 ) PRIM ENCLOSE 10 ( addr c -- addr next first last ) PRIM KEY 11 ( -- c ) PRIM (EMIT) 12 ( c -- ) PRIM ?TERMINAL 13 ( see if op. interrupted ) PRIM CMOVE 14 ( src dest count -- ) PRIM U* 15 ( unsigned multiply ) PRIM U/ 16 ( unsigned divide ) PRIM AND 17 ( a b -- a&b ) PRIM OR 18 ( a b -- a|b ) PRIM XOR 19 ( a b -- a%b ) PRIM SP@ 20 ( -- sp ) PRIM SP! 21 ( -- ) PRIM RP@ 22 ( -- rp ) PRIM RP! 23 ( -- ) PRIM ;S 24 ( -- > ) PRIM LEAVE 25 ( -- ) PRIM >R 26 ( a -- ) PRIM R> 27 ( -- a ) PRIM 0< 29 ( a -- a<0 ) PRIM + 30 ( a b -- a+b ) PRIM D+ 31 ( ahi alo bhi blo -- a+bhi a+blo ) PRIM MINUS 32 ( a -- -a ) PRIM DMINUS 33 ( ahi alo -- <-a>hi <-a>lo ) PRIM OVER 34 ( a b -- a b a ) PRIM DROP 35 ( a -- ) PRIM SWAP 36 ( a b -- b a ) PRIM DUP 37 ( a -- a a ) PRIM 2DUP 38 ( a b -- a b a b ) PRIM +! 39 ( val addr -- < *addr += val > ) PRIM TOGGLE 40 ( addr mask -- <*addr %= mask> ) PRIM @ 41 ( addr -- *addr ) PRIM C@ 42 ( addr -- *addr ) PRIM 2@ 43 ( addr -- *addr+1 *addr ) PRIM ! 44 ( val addr -- <*addr = val> ) PRIM C! 45 ( val addr -- <*addr = val> ) PRIM 2! 46 ( bhi blo addr -- <*addr=blo, *addr+1=bhi ) PRIM DOCOL 47 ( goes into CF of : definitions ) PRIM DOCON 48 ( goes into CF of constants ) PRIM DOVAR 49 ( goes into CF of variables ) PRIM DOUSE 50 ( goes into CF of user variables ) PRIM - 51 ( a b -- a-b ) PRIM = 52 ( a b -- a==b) PRIM != 53 ( a b -- a!=b) PRIM < 54 ( a b -- a; ) PRIM TRON 61 ( depth -- trace to this depth ) PRIM TROFF 62 ( stop tracing ) PRIM DOTRACE 63 ( trace once ) PRIM (R/W) 64 ( BUFFER FLAG ADDR -- read if flag=1, write/0 ) PRIM (SAVE) 65 ( Save current environment ) PRIM (COLD) 66 ( end of primitives ) CONST 0 0 CONST 1 1 CONST 2 2 CONST 3 3 CONST -1 -1 CONST BL 32 ( A SPACE, OR BLANK ) CONST C/L 64 CONST B/BUF 1024 CONST B/SCR 1 CONST #BUFF 5 ( IMPLEMENTATION DEPENDENT ) CONST WORDSIZE 1 ( EXTENSION: WORDSIZE IS THE NUMBER OF BYTES IN A WORD. USUALLY, THIS IS TWO, BUT WITH PSEUDO-MEMORY ADDRESSED AS AN ARRAY OF WORDS, IT'S ONE. ) CONST FIRST 0 ( ADDRESS OF THE FIRST BUFFER AND END OF BUFFER SPACE ) CONST LIMIT 0 ( the reader fills these in with INITR0 and DPBASE ) USER S0 24 USER R0 25 USER TIB 26 USER WIDTH 27 USER WARNING 28 USER FENCE 29 USER DP 30 USER VOC-LINK 31 USER BLK 32 USER IN 33 USER ERRBLK 34 USER ERRIN 35 USER OUT 36 USER SCR 37 USER OFFSET 38 USER CONTEXT 39 USER CURRENT 40 USER STATE 41 USER BASE 42 USER DPL 43 USER FLD 44 USER CSP 45 USER R# 46 USER HLD 47 VAR USE 0 ( These two are filled in by COLD ) VAR PREV 0 ( to the same as the constant FIRST ) CONST SEC/BLK 1 : EMIT (EMIT) 1 OUT +! ; : CR LIT 13 EMIT LIT 10 EMIT 0 OUT ! ; : NOP ; ( DO-NOTHING ) : +ORIGIN ; ( ADD ORIGIN OF SYSTEM; IN THIS CASE, 0 ) : 1+ 1 + ; : 2+ 2 + ; : 1- 1 - ; : ++ ( ADDR -- ) 1 SWAP +! ; ( MY OWN EXTENSION ) : -- ( ADDR -- ) -1 SWAP +! ; ( MY OWN EXTENSION ) : HERE ( -- DP ) DP @ ; : , ( V -- ) HERE ! WORDSIZE ALLOT ; ( CHANGE FROM MODEL FOR WORDSIZE ) : C, ( C -- ) HERE C! 1 ALLOT ; : U< ( THIS IS TRICKY. ) 2DUP XOR 0< ( SIGNS DIFFERENT? ) 0BRANCH U1 ( NO: GO TO U1 ) DROP 0< 0= ( YES; ANSWER IS [SECOND > 0] ) BRANCH U2 ( SKIP TO U2 ) LABEL U1 - 0< ( SIGNS ARE THE SAME. JUST SUBTRACT AND TEST NORMALLY ) LABEL U2 ; : > ( CHEAP TRICK ) SWAP < ; : <> ( NOT-EQUAL ) != ; : SPACE ( EMIT A SPACE ) BL EMIT ; : -DUP ( V -- V | V V ) DUP 0BRANCH DDUP1 ( SKIP TO END IF IT WAS ZERO ) DUP LABEL DDUP1 ; : TRAVERSE ( A DIR -- A OR LFA TO NFA ) SWAP LABEL T1 OVER ( BEGIN ) + LIT 0x7F OVER C@ < ( HIGH BIT CLEAR? ) 0BRANCH T1 ( UNTIL ) SWAP DROP ; : LATEST ( NFA OF LAST WORD DEFINED ) CURRENT @ @ ; : LFA ( GO FROM PFA TO LFA ) 2 - ; ( 2 IS WORDSIZE*2 ) : CFA ( GO FROM PFA TO CFA ) WORDSIZE - ; : NFA ( GO FROM PFA TO NFA ) 3 - ( NOW AT LAST CHAR ) -1 TRAVERSE ; ( 3 IS WORDSIZE*3 ) : PFA ( GO FROM NFA TO PFA ) 1 TRAVERSE ( NOW AT LAST CHAR ) 3 + ; ( 3 IS WORDSIZE*3 ) : !CSP ( SAVE CSP AT USER VAR CSP ) SP@ CSP ! ; : (ABORT) ABORT ; : ERROR ( N -- ) WARNING @ 0< ( WARNING < 0 MEANS ) 0BRANCH E1 (ABORT) ( IF ) LABEL E1 HERE COUNT TYPE (.") "?" ( THEN ) MESSAGE SP! ( EMPTY THE STACK ) BLK @ -DUP ( IF LOADING, STORE IN & BLK ) 0BRANCH E2 ERRBLK ! IN @ ERRIN ! ( IF ) LABEL E2 QUIT ( THEN ) ; : ?ERROR ( F N -- ) SWAP 0BRANCH QERR1 ERROR ( IF ) LABEL QERR1 DROP ( THEN ) ; : ?COMP ( GIVE ERR#17 IF NOT COMPILING ) STATE @ 0= LIT 17 ?ERROR ; : ?EXEC ( GIVE ERR#18 IF NOT EXECUTING ) STATE @ LIT 18 ?ERROR ; : ?PAIRS ( GIVE ERR#19 IF PAIRS DON'T MATCH ) - LIT 19 ?ERROR ; : ?CSP ( GIVE ERR#20 IF CSP & SP DON'T MATCH ) SP@ CSP @ - LIT 20 ?ERROR ; : ?LOADING ( GIVE ERR#21 IF NOT LOADING ) BLK @ 0= LIT 22 ?ERROR ; : COMPILE ( COMPILE THE CFA OF THE NEXT WORD TO DICT ) ?COMP R> DUP ( GET OUR RETURN ADDRESS ) WORDSIZE + >R ( SKIP NEXT; ORIG. ADDR STILL ON TOS ) @ , ; : [ ( BEGIN EXECUTING ) 0 STATE ! ;* : ] ( END EXECUTING ) LIT 0xC0 STATE ! ;* : SMUDGE ( TOGGLE COMPLETION BIT OF LATEST WORD ) LATEST ( WHEN THIS BIT=1, WORD CAN'T BE FOUND ) LIT 0x20 TOGGLE ; : : ( DEFINE A WORD ) ?EXEC !CSP CURRENT @ CONTEXT ! CREATE ] ( MAKE THE WORD HEADER AND BEGIN COMPILING ) (;CODE) DOCOL ;* : ; ( END A DEFINITION ) ?CSP ( CHECK THAT WE'RE DONE ) COMPILE ;S ( PLACE ;S AT THE END ) SMUDGE [ ( MAKE THE WORD FINDABLE AND BEGIN INTERPRETING ) ;* : CONSTANT CREATE SMUDGE , (;CODE) DOCON ; : VARIABLE CONSTANT (;CODE) DOVAR ; : USER CONSTANT (;CODE) DOUSE ; : HEX ( GO TO HEXADECIMAL BASE ) LIT 0x10 BASE ! ; : DECIMAL ( GO TO DECIMAL BASE ) LIT 0x0A BASE ! ; : ;CODE ( unused without an assembler ) ?CSP COMPILE (;CODE) [ NOP ( "ASSEMBLER" might go where nop is ) ;* : (;CODE) ( differs from the normal def'n ) R> @ @ LATEST PFA CFA ! ; : ( UNSURE ) R> LATEST PFA ! (;CODE) DODOES ; : COUNT ( ADDR -- ADDR+1 COUNT ) DUP 1+ SWAP C@ ; ( CONVERTS THE ADDR TO A FORM SUITABLE FOR "TYPE" ) : TYPE -DUP 0BRANCH TYPE1 OVER + SWAP ( GET START .. END ADDRS ) (DO) LABEL TYPE2 I C@ EMIT (LOOP) TYPE2 BRANCH TYPE3 LABEL TYPE1 DROP LABEL TYPE3 ; : -TRAILING ( addr count -- addr count ) DUP 0 (DO) ( DO ) LABEL TRAIL1 OVER OVER + 1 - C@ BL - 0BRANCH TRAIL2 LEAVE BRANCH TRAIL3 ( IF ) LABEL TRAIL2 1 - ( ELSE ) LABEL TRAIL3 (LOOP) TRAIL1 ( THEN LOOP ) ; : (.") ( PRINT A COMPILED STRING ) R COUNT DUP 1+ R> + >R TYPE ; : ." ( COMPILE A STRING IF COMPILING, OR PRINT A STRING IF INTERPRETING ) LIT '"' STATE @ 0BRANCH QUOTE1 COMPILE (.") WORD HERE C@ 1+ ALLOT ( IF ) BRANCH QUOTE2 LABEL QUOTE1 WORD HERE COUNT TYPE ( ELSE ) LABEL QUOTE2 ;* ( THEN ) : EXPECT ( MODIFIED EXPECT lets UNIX input editing & echoing ) ( change EMIT to DROP below if not -echo ) OVER + OVER ( start of input buffer is on top of stack ) DUP 0 SWAP C! ( smack a zero at the start to catch empty lines ) (DO) ( above is an added departure ) LABEL EXPEC1 KEY ( Comment this region out if using stty cooked ) DUP LIT 8 = 0BRANCH EXPEC2 DROP DUP I = DUP R> 2 - + >R 0BRANCH EXPEC6 LIT 7 BRANCH EXPEC7 LABEL EXPEC6 LIT 8 ( output for backspace ) LABEL EXPEC7 BRANCH EXPEC3 ( End of region to comment out for stty cooked ) LABEL EXPEC2 DUP LIT '\n' = 0BRANCH EXPEC4 ( IF ) LEAVE DROP BL 0 BRANCH EXPEC5 LABEL EXPEC4 ( ELSE ) DUP LABEL EXPEC5 ( THEN ) I C! 0 I 1+ ! LABEL EXPEC3 EMIT ( use DROP here for stty echo, EMIT for -echo ) (LOOP) EXPEC1 DROP ; : QUERY TIB @ ( ADDRESS OF BUFFER ) B/BUF ( SIZE OF BUFFER ) EXPECT ( GET A LINE ) 0 IN ! ( PREPARE FOR INTERPRET ) ; : {NUL} ( THIS GETS TRANSLATED INTO A SINGLE NULL BYTE ) BLK @ 0BRANCH NULL1 BLK ++ 0 IN ! ( IF ) BLK @ B/SCR 1 - AND 0= 0BRANCH NULL2 ?EXEC R> ( IF ) DROP LABEL NULL2 BRANCH NULL3 ( ENDIF ELSE ) LABEL NULL1 R> DROP LABEL NULL3 ( ENDIF ) ;* : FILL ( START COUNT VALUE -- ) DUP 1+ ROT 1 - CMOVE BRANCH FILL2 LABEL FILL1 DROP DROP LABEL FILL2 ; : ERASE ( START COUNT -- ) 0 FILL ; : BLANKS ( START COUNT -- ) BL FILL ; : HOLD ( C -- ) HLD -- HLD @ C! ; : PAD ( -- ADDR ) HERE LIT 0x44 + ; : WORD ( C -- R R HERE C! + HERE 1+ R> CMOVE ; : (NUMBER) LABEL NUM1 1+ DUP >R C@ BASE @ DIGIT 0BRANCH NUM2 ( WHILE ) SWAP BASE @ U* DROP ROT BASE @ U* D+ DPL @ 1+ 0BRANCH NUM3 DPL ++ ( IF ) LABEL NUM3 R> ( ENDIF ) BRANCH NUM1 ( REPEAT ) LABEL NUM2 R> ; : NUMBER 0 0 ROT DUP 1+ C@ LIT '-' = DUP >R + -1 LABEL N1 ( BEGIN ) DPL ! (NUMBER) DUP C@ BL != 0BRANCH N2 ( WHILE ) DUP C@ LIT '0' != 0 ?ERROR 0 ( . ) BRANCH N1 ( REPEAT ) LABEL N2 DROP R> 0BRANCH N3 ( IF ) DMINUS LABEL N3 ( ENDIF ) ; : -FIND BL WORD ( HERE CONTEXT @ @ DUP 0= 0BRANCH FIND1 DROP ) HERE LATEST (FIND) ( LABEL FIND1 ) ; : ID. ( NFA -- ) PAD LIT 0x5F BLANKS DUP PFA LFA OVER - PAD SWAP CMOVE PAD COUNT LIT 0x1F AND TYPE SPACE ; : CREATE ( MAKE A HEADER FOR THE NEXT WORD ) -FIND 0BRANCH C1 DROP NFA ID. LIT 4 MESSAGE SPACE ( NOT UNIQUE ) LABEL C1 HERE DUP C@ WIDTH @ MIN 1+ ALLOT ( MAKE ROOM ) DUP LIT 0xA0 TOGGLE ( MAKE IT UNFINDABLE ) HERE 1 - LIT 0x80 TOGGLE ( SET HI BIT ) LATEST , ( DO LF ) CURRENT @ ! ( UPDATE FOR LATEST ) LIT 999 , ( COMPILE ILLEGAL VALUE TO CODE FIELD ) ; : [COMPILE] ( COMPILE THE NEXT WORD, EVEN IF IT'S IMMEDIATE ) -FIND 0= 0 ?ERROR DROP CFA , ;* : LITERAL STATE @ 0BRANCH L1 COMPILE LIT , LABEL L1 ;* : DLITERAL STATE @ 0BRANCH D1 SWAP LITERAL LITERAL LABEL D1 ;* : ?STACK ( ERROR IF STACK OVERFLOW OR UNDERFLOW ) S0 @ SP@ U< 1 ?ERROR ( SP > S0 MEANS UNDERFLOW ) SP@ TIB @ U< LIT 7 ?ERROR ( SP < R0 MEANS OVERFLOW: THIS IS IMPLEMENTATION- DEPENDENT; I KNOW THAT THE CS IS JUST ABOVE THE TIB. ) ; : INTERPRET LABEL I1 -FIND ( BEGIN ) 0BRANCH I2 STATE @ < ( IF ) 0BRANCH I3 CFA , ( IF ) BRANCH I4 LABEL I3 CFA EXECUTE ( ELSE ) LABEL I4 ?STACK ( ENDIF ) BRANCH I5 LABEL I2 HERE NUMBER DPL @ 1+ 0BRANCH I6 DLITERAL ( IF ) BRANCH I7 LABEL I6 DROP LITERAL ( ELSE ) LABEL I7 ?STACK ( ENDIF ENDIF ) LABEL I5 BRANCH I1 ( AGAIN ) ; : IMMEDIATE ( MAKE MOST-RECENT WORD IMMEDIATE ) LATEST LIT 0x40 TOGGLE ; ( *** These are commented out because we don't handle vocabularies *** : VOCABULARY WORDSIZE + CONTEXT ! ; : DEFINITIONS CONTEXT @ CURRENT ! ; *** End of commenting-out *** ) : ( ( COMMENT ) LIT ')' ( CLOSING PAREN ) WORD ;* : QUIT 0 BLK ! [ LABEL Q1 RP! CR QUERY INTERPRET ( BEGIN ) STATE @ 0= 0BRANCH Q2 (.") "OK" ( IF ) LABEL Q2 BRANCH Q1 ( ENDIF AGAIN ) ; : ABORT SP! DECIMAL ?STACK CR .CPU ( PRINT THE GREETING ) ( FORTH ) QUIT ; : COLD (COLD) VOC-LINK @ CONTEXT ! ( INITIALIZE CONTEXT ) CONTEXT @ CURRENT ! ( MAKE CONTEXT CURRENT ) FIRST USE ! FIRST PREV ! EMPTY-BUFFERS 1 WARNING ! ( USE SCREEN 4 FOR ERROR MESSAGES ) ABORT ; : WARM EMPTY-BUFFERS ABORT ; : S->D DUP 0< 0BRANCH S2D1 -1 ( HIGH WORD IS ALL 1S ) BRANCH S2D2 LABEL S2D1 0 LABEL S2D2 ; : +- 0< 0BRANCH PM1 MINUS LABEL PM1 ; : D+- 0< 0BRANCH DPM1 DMINUS LABEL DPM1 ; : ABS DUP +- ; : DABS DUP D+- ; : MIN 2DUP > 0BRANCH MIN1 SWAP LABEL MIN1 DROP ; : MAX 2DUP < 0BRANCH MAX1 SWAP LABEL MAX1 DROP ; ( MATH STUFF ) : M* 2DUP XOR >R ABS SWAP ABS U* R> D+- ; : M/ OVER >R >R DABS R ABS U/ R> R XOR +- SWAP R> +- SWAP ; : * ( MULTIPLY, OF COURSE ) M* DROP ; : /MOD >R S->D R> M/ ; : / ( DIVIDE ) /MOD SWAP DROP ; : MOD /MOD DROP ; : */MOD >R M* R> M/ ; : */ */MOD SWAP DROP ; : M/MOD >R 0 R U/ R> SWAP >R U/ R> ; ( END OF MATH STUFF ) : (LINE) ( LINE SCR -- ADDR C/L ) >R C/L B/BUF */MOD R> B/SCR * + BLOCK + C/L ; : .LINE ( LINE SCR -- ) (LINE) -TRAILING TYPE ; : MESSAGE WARNING @ 0BRANCH MSG1 -DUP 0BRANCH MSG2 ( message # 0 is no message at all ) LIT 4 OFFSET @ B/SCR / - .LINE SPACE ( messages are on screen 4 ) BRANCH MSG2 LABEL MSG1 (.") "MSG # " . LABEL MSG2 ; ( DISK-ORIENTED WORDS ) : +BUF LIT 1028 ( 1K PLUS 4 BYTES OVERHEAD, CO from defines ) + DUP LIMIT = 0BRANCH P1 DROP FIRST LABEL P1 DUP PREV @ - ; : UPDATE ( MARK BUFFER AS MODIFIED ) PREV @ @ LIT 0X8000 OR PREV @ ! ; : EMPTY-BUFFERS FIRST LIMIT OVER - ERASE ; : BUFFER USE @ DUP >R LABEL BUF1 +BUF 0BRANCH BUF1 ( LOOP UNTIL +BUF RETURNS NONZERO ) USE ! R @ 0< 0BRANCH BUF2 ( SEE IF IT'S DIRTY ) R 2+ R @ LIT 0X7FFF AND 0 R/W ( WRITE THIS DIRTY BUFFER ) LABEL BUF2 R ! R PREV ! R> 2+ ; : BLOCK OFFSET @ + >R PREV @ DUP @ R - DUP + 0BRANCH BLOCK1 LABEL BLOCK2 +BUF 0= 0BRANCH BLOCK3 DROP R BUFFER DUP R 1 R/W 2 - LABEL BLOCK3 DUP @ R - DUP + 0= 0BRANCH BLOCK2 DUP PREV ! LABEL BLOCK1 R> DROP 2+ ; : R/W ( ADDR F BUFNO -- read if F=1, write if 0 ) (R/W) ; : FLUSH #BUFF 1+ 0 (DO) LABEL FLUSH1 0 BUFFER DROP (LOOP) FLUSH1 ; : LOAD BLK @ >R IN @ >R 0 IN ! B/SCR * BLK ! INTERPRET R> IN ! R> BLK ! ; : --> (.") "--> " ?LOADING 0 IN ! B/SCR BLK @ OVER MOD - BLK +! ;* : ' -FIND 0= 0 ?ERROR DROP LITERAL ;* : FORGET CURRENT @ CONTEXT @ - LIT 24 ?ERROR ' DUP FENCE @ < LIT 21 ?ERROR DUP NFA DP ! LFA @ CONTEXT @ ! ; ( COMPILING WORDS ) : BACK HERE - , ; : BEGIN ?COMP HERE 1 ;* : ENDIF ?COMP 2 ?PAIRS HERE OVER - SWAP ! ;* : THEN ENDIF ;* : DO COMPILE (DO) HERE LIT 3 ;* : LOOP LIT 3 ?PAIRS COMPILE (LOOP) BACK ;* : +LOOP LIT 3 ?PAIRS ?COMP COMPILE (+LOOP) BACK ;* : UNTIL 1 ?PAIRS COMPILE 0BRANCH BACK ;* : END UNTIL ;* : AGAIN ?COMP 1 ?PAIRS COMPILE BRANCH BACK ;* : REPEAT ?COMP >R >R AGAIN R> R> 2 - ENDIF ;* : IF COMPILE 0BRANCH HERE 0 , 2 ;* : ELSE 2 ?PAIRS COMPILE BRANCH HERE 0 , SWAP 2 ENDIF 2 ;* : WHILE IF 2+ ;* : SPACES 0 MAX -DUP 0BRANCH SPACES1 0 (DO) LABEL SPACES2 SPACE (LOOP) SPACES2 LABEL SPACES1 ; : <# PAD HLD ! ; : #> DROP DROP HLD @ PAD OVER - ; : SIGN ROT 0< 0BRANCH SIGN1 LIT '-' HOLD LABEL SIGN1 ; : # BASE @ M/MOD ROT LIT 9 OVER < 0BRANCH #1 LIT 7 + ( 7 is offset to make 'A' come after '9') LABEL #1 LIT '0' + HOLD ; : #S LABEL #S1 # 2DUP OR 0= 0BRANCH #S1 ; : D.R >R SWAP OVER DABS <# #S SIGN #> R> OVER - SPACES TYPE ; : .R >R S->D R> D.R ; : D. 0 D.R SPACE ; : . S->D D. ; : ? @ . ; : U. 0 D. ; : VLIST C/L 1+ OUT ! CONTEXT @ @ LABEL VLIST1 ( BEGIN ) OUT @ C/L > 0BRANCH VLIST2 ( IF ) CR LABEL VLIST2 ( THEN ) DUP ID. SPACE PFA LFA @ DUP 0= ?TERMINAL OR 0BRANCH VLIST1 ( UNTIL ) DROP ; : .CPU (.") "C-CODED FORTH INTERPRETER" ( special string handling ) ; : BYE CR (.") "EXIT FORTH" CR 0 (BYE) ; : LIST DECIMAL CR DUP SCR ! (.") "SCR # " . LIT 16 0 (DO) LABEL LIST1 CR I 3 .R SPACE I SCR @ .LINE ?TERMINAL 0BRANCH LIST2 LEAVE LABEL LIST2 (LOOP) LIST1 CR ; : CASE ?COMP CSP @ !CSP LIT 4 ;* : OF ?COMP LIT 4 ?PAIRS COMPILE OVER COMPILE = COMPILE 0BRANCH HERE 0 , COMPILE DROP LIT 5 ;* : ENDOF ?COMP LIT 5 ?PAIRS COMPILE BRANCH HERE 0 , SWAP 2 ENDIF LIT 4 ;* : ENDCASE ?COMP LIT 4 ?PAIRS COMPILE DROP LABEL ENDC1 ( BEGIN ) SP@ CSP @ != 0BRANCH ENDC2 ( WHILE ) 2 ENDIF BRANCH ENDC1 ( REPEAT ) LABEL ENDC2 CSP ! ;* : \ ( REMAINER OF THE LINE IS A COMMENT ) ?LOADING IN @ C/L / 1+ C/L * IN ! ;* : ALIAS ( usage: ALIAS NEW OLD; makes already-compiled references ) ( to OLD refer to NEW. Restrictions: OLD must have been a ) ( colon-definition, and it must not have been of the form ) ( { : OLD ; } where the first word of the PFA is ;S . ) ' CFA ' DUP 2 - @ LIT DOCOL != LIT 27 ?ERROR ( ERROR IF NOT A COLON DEFINITION ) DUP @ LIT ;S = LIT 28 ?ERROR ( MAKE SURE ;S IS NOT THE FIRST WORD ) DUP >R ! LIT ;S R> 2+ ! ; : REFORTH ( GET & EXECUTE ONE FORTH LINE ) IN @ >R BLK @ >R 0 IN ! 0 BLK ! QUERY INTERPRET R> BLK ! R> IN ! ; ( The vocabulary word FORTH will be compiled after the dictionary is read, with a pointer to the last word in the dictionary, which will be itself. ) //go.sysin dd * echo 'x - forth.h' sed 's/^X//' <<'//go.sysin dd *' >forth.h X/* * forth.h -- define function numbers for primitives, and other constants, * externals, and globals used in forth.c and prims.c */ #define EXECUTE 0 #define LIT 1 #define BRANCH 2 #define ZBRANCH 3 #define PLOOP 4 #define PPLOOP 5 #define PDO 6 #define I 7 #define R 58 #define DIGIT 8 #define PFIND 9 #define ENCLOSE 10 #define KEY 11 #define PEMIT 12 #define QTERMINAL 13 #define CMOVE 14 #define USTAR 15 #define USLASH 16 #define AND 17 #define OR 18 #define XOR 19 #define SPFETCH 20 #define SPSTORE 21 #define RPFETCH 22 #define RPSTORE 23 #define SEMIS 24 #define LEAVE 25 #define TOR 26 #define FROMR 27 #define ZEQ 28 #define ZLESS 29 #define PLUS 30 #define DPLUS 31 #define MINUS 32 #define DMINUS 33 #define OVER 34 #define DROP 35 #define SWAP 36 #define DUP 37 #define TDUP 38 #define PSTORE 39 #define TOGGLE 40 #define FETCH 41 #define CFETCH 42 #define TFETCH 43 #define STORE 44 #define CSTORE 45 #define TSTORE 46 #define DOCOL 47 #define DOCON 48 #define DOVAR 49 #define DOUSE 50 #define SUBTRACT 51 #define EQUAL 52 #define NOTEQ 53 #define LESS 54 #define ROT 55 #define DODOES 56 #define DOVOC 57 X/* 58 is above */ #define ALLOT 59 #define PBYE 60 #define TRON 61 #define TROFF 62 #define DOTRACE 63 #define PRSLW 64 #define PSAVE 65 #define PCOLD 66 X/* memory */ #define GULPFRQ 256 /* if mem[LIMIT] - dp < GULPFRQ, then get */ #define GULPSIZE 1024 /* a block of GULPSIZE words */ X/* * User variables and other locations */ #define S0 UP+0 /* csp when stack is empty */ #define R0 UP+1 /* rsp when r stack is empty */ #define TIB UP+2 /* Terminal Input Buffer location */ #define WIDTH UP+3 /* screen width */ #define WARNING UP+4 /* print messages? */ #define FENCE UP+5 /* can not forget below this mark */ #define DP UP+6 /* points to first unallocated word */ #define VOCLINK UP+7 /* vocabulary link */ char *calloc(), *realloc(), *gets(); long lseek(); X/* GLOBALS */ X/* STACK POINTERS are registers of our FORTH machine. They, like everything else, point into memory (mem[]). They are read by sp@ and rp@, set by sp! and rp!. They are initialized by COLD. */ extern unsigned short csp; extern unsigned short rsp; X/* This variable is all-important. It will be set to the top of the data area by sbrk, and more memory will be allocated. All memory is addressed as a subscript to this address -- mem[0] is the first memory element, mem[1] is second, and so on. */ extern short *mem; /* points to the number of bytes in mem[0], as read from COREFILE at startup */ X/* two more machine registers: the interpretive pointer */ extern unsigned short ip; /* for an explanation of these, look in */ extern unsigned short w; /* interp.doc */ extern int trace, debug; /* global for tracing in next() */ extern int tracedepth, breakenable, breakpoint, qtermflag, forceip, nobuf; extern FILE *blockfile; extern long bfilesize; extern char *bfilename; extern char *cfilename; extern char *sfilename; //go.sysin dd * echo 'x - forth.lex' sed 's/^X//' <<'//go.sysin dd *' >forth.lex %{ X/* LEX input for FORTH input file scanner */ X/* Specifications are as follows: This file must be run through "sed" to change yylex () { to TOKEN *yylex () { where the sed script is sed "s/yylex () {/TOKEN *yylex () {/" lex.yy.c Note that spaces have been included above so these lines won't be mangled by sed; in actuality, the two blanks surrounding () are removed. The function "yylex()" always returns a pointer to a structure: struct tokenrec { int type; char *text; } #define TOKEN struct tokenrec where the type is a hint as to the word's type: DECIMAL for decimal literal d+ OCTAL for octal literal 0d* HEX for hex literal 0xd+ or 0Xd+ C_BS for a literal Backspace '\b' C_FF for a literal Form Feed '\f' C_NL for a literal Newline '\n' C_CR for a literal Carriage Return '\r' C_TAB for a literal Tab '\t' C_BSLASH for a literal backslash '\\' C_IT for an other character literal 'x' where x is possibly ' STRING_LIT for a string literal (possibly containing \") COMMENT for a left-parenthesis (possibly beginning a comment) PRIM for "PRIM" CONST for "CONST" VAR for "VAR" USER for "USER" LABEL for "LABEL" COLON for ":" SEMICOLON for ";" SEMISTAR for ";*" (used to make words IMMEDIATE) NUL for the token {NUL}, which gets compiled as a null byte; this special interpretation takes place in the COLON code. LIT for the word "LIT" (treated like OTHER, except that no warning is generated when a literal follows this) OTHER for an other word not recognized above Note that this is just a hint: the meaning of any string of characters depends on the context. */ %} decimal [0-9] hex [0-9A-Fa-f] octal [0-7] white [ \t\n\r\f] tail /{white} %{ #include "forth.lex.h" TOKEN token; %} %% {white}* /* whitespace -- keep looping */ ; -?[1-9]{decimal}*{tail} { token.type = DECIMAL; token.text = yytext; return &token; } -?0{octal}*{tail} { token.type = OCTAL; token.text = yytext; return &token; } -?0[xX]{hex}+{tail} { token.type = HEX; token.text = yytext; return &token; } \'\\b\'{tail} { token.type = C_BS; token.text = yytext; return &token; } \'\\f\'{tail} { token.type = C_FF; token.text = yytext; return &token; } \'\\n\'{tail} { token.type = C_NL; token.text = yytext; return &token; } \'\\r\'{tail} { token.type = C_CR; token.text = yytext; return &token; } \'\\t\'{tail} { token.type = C_TAB; token.text = yytext; return &token; } \'\\\\\'{tail} { token.type = C_BSLASH; token.text = yytext; return &token; } \'.\'{tail} { token.type = C_LIT; token.text = yytext; return &token; } \"(\\\"|[^"])*\"{tail} { token.type = STRING_LIT; token.text = yytext; return &token; } "("{tail} { token.type = COMMENT; token.text = yytext; return &token; } "PRIM"{tail} { token.type = PRIM; token.text = yytext; return &token; } "CONST"{tail} { token.type = CONST; token.text = yytext; return &token; } "VAR"{tail} { token.type = VAR; token.text = yytext; return &token; } "USER"{tail} { token.type = USER; token.text = yytext; return &token; } "LABEL"{tail} { token.type = LABEL; token.text = yytext; return &token; } ":"{tail} { token.type = COLON; token.text = yytext; return &token; } ";"{tail} { token.type = SEMICOLON; token.text = yytext; return &token; } ";*"{tail} { token.type = SEMISTAR; token.text = yytext; return &token; } "{NUL}"{tail} { token.type = NUL; token.text = yytext; return &token; } "LIT"{tail} { token.type = LIT; token.text = yytext; return &token; } [^ \n\t\r\f]+{tail} { token.type = OTHER; token.text = yytext; return &token; } %% //go.sysin dd * echo 'x - forth.lex.h' sed 's/^X//' <<'//go.sysin dd *' >forth.lex.h X/* this is my best effort at a reconstruction of this file - it was not ** included with the distribution, and I cannot reach the author via ** electronic mail! ** John Nelson (decvax!genrad!john) [moderator, mod.sources] */ struct tokenrec { int type; char *text; }; #define TOKEN struct tokenrec TOKEN *yylex(); #define DECIMAL 1 #define OCTAL 2 #define HEX 3 #define C_BS 4 #define C_FF 5 #define C_NL 6 #define C_CR 7 #define C_TAB 8 #define C_BSLASH 9 #define C_LIT 10 #define STRING_LIT 11 #define COMMENT 12 #define PRIM 13 #define CONST 14 #define VAR 15 #define USER 16 #define LABEL 17 #define COLON 18 #define SEMICOLON 19 #define SEMISTAR 20 #define NUL 21 #define LIT 22 #define OTHER 23 //go.sysin dd * echo 'x - forth.line' sed 's/^X//' <<'//go.sysin dd *' >forth.line ------------------ SCREEN 0 ------------------ ================================================================ || C-CODED FIG-FORTH for UNIX* systems by ALLAN PRATT || || || || INCLUDES \ COMMENTS, || || CASE..OF..ENDOF..ENDCASE || || UNTHREAD, EDITOR || || REFORTH, || || "ALIAS NEW OLD" || || AND OTHER NICE THINGS. || || ( * UNIX is a trademark of Bell Labs ) || ================================================================ ------------------ SCREEN 1 ------------------ ( UNTHREAD VERSION 2 / SCREEN 1 OF 3 ) : DOQUOTE \ AFTER (.") 34 EMIT WORDSIZE + DUP C@ OVER 1+ SWAP TYPE 34 EMIT SPACE DUP C@ + 1+ ; : DOLIT \ AFTER LIT, BRANCHES, AND (LOOP)S WORDSIZE + DUP @ . WORDSIZE + ; --> ------------------ SCREEN 2 ------------------ ( UNTHREAD VERSION 2 / SCREEN 2 OF 3 ) : DOWORD \ MAIN UNTHREADER DUP @ WORDSIZE + DUP NFA ID. CASE ' LIT OF DOLIT ENDOF ' 0BRANCH OF DOLIT ENDOF ' BRANCH OF DOLIT ENDOF ' (LOOP) OF DOLIT ENDOF ' (+LOOP) OF DOLIT ENDOF ' (.") OF DOQUOTE ENDOF ' ;S OF DROP 0 ENDOF \ LEAVE 0 DUP OF WORDSIZE + ENDOF \ DEFAULT ENDCASE ; --> ------------------ SCREEN 3 ------------------ ( UNTHREAD VERSION 2 / SCREEN 3 OF 3 ) : UNTHREAD \ USAGE: UNTHREAD WORD [COMPILE] ' DUP CFA @ ' DOWORD CFA @ <> 27 ?ERROR \ NOT THREADED CR ." : " DUP NFA ID. SPACE BEGIN DOWORD OUT @ C/L > IF CR THEN -DUP WHILE REPEAT ; CR ." UNTHREAD READY" ;S ------------------ SCREEN 4 ------------------ ( ERROR MESSAGES ) EMPTY STACK ISN'T UNIQUE XFULL STACK C-CODED figFORTH by ALLAN PRATT / APRIL 1985 ------------------ SCREEN 5 ------------------ MSG # 16 MUST BE COMPILING MUST BE EXECUTING UNMATCHED STRUCTURES DEFINITION NOT FINISHED WORD IS PROTECTED BY FENCE MUST BE LOADING CONTEXT ISN'T CURRENT ALIAS: NOT A COLON DEFINITION ALIAS: CAN'T ALIAS A NULL WORD ------------------ SCREEN 6 ------------------ X." LOADING EDITOR FOR VT100" CR : CLS \ clear screen and home cursor 27 EMIT ." [2J" 27 EMIT ." [H" ; : LOCATE \ 0 16 LOCATE positions cursor at line 16, column 0 27 EMIT 91 EMIT 1+ 1 .R 59 EMIT 1+ 1 .R 72 EMIT ; : STANDOUT \ This can be a null word 27 EMIT ." [7m" ; : STANDEND \ This can be a null word, too. 27 EMIT ." [m" ; ;S \ CONTINUE LOADING EDITOR ------------------ SCREEN 7 ------------------ X." LOADING EDITOR FOR ADM5" CR : CLS 26 EMIT ; : LOCATE 27 EMIT 61 EMIT 32 + EMIT 32 + EMIT ; : STANDOUT 27 EMIT 71 EMIT ; : STANDEND 27 EMIT 71 EMIT ; ;S \ continue loading editor ------------------ SCREEN 8 ------------------ ( Reserved for more terminals; set the name of the terminal as a constant in screen 10 ) ;S ------------------ SCREEN 9 ------------------ ( Reserved for more terminals. Set the name of the terminal as a constant in screen 10 ) ;S ------------------ SCREEN 10 ------------------ ( EDITOR -- SCREEN 1 OF 19 -- VARIABLES ) DECIMAL 0 VARIABLE ROW 0 VARIABLE COL 0 VARIABLE EDIT-SCR 0 VARIABLE SCREEN-IS-MODIFIED 0 VARIABLE MUST-UPDATE 0 VARIABLE LAST-KEY-STRUCK 0 VARIABLE CURSOR-IS-DIRTY 0 VARIABLE KEYMAP WORDSIZE 255 * ALLOT KEYMAP WORDSIZE 256 * ERASE 0 VARIABLE SCR-BUFFER B/BUF B/SCR * WORDSIZE - ALLOT ( TERMINAL CONSTANTS -- VALUE IS SCREEN NUMBER TO LOAD ) 6 CONSTANT VT100 7 CONSTANT ADM5 --> ------------------ SCREEN 11 ------------------ ( EDITOR -- SCREEN 2 OF 19 -- SCREEN STUFF ) CR ." ENTER THE TYPE OF TERMINAL YOU ARE USING. TYPE ONE OF:" CR ." VT100 ADM5" CR \ list the constants from scr 10 REFORTH \ this word gets & interprets one line. LOAD \ load the right screen; VT100 = 6, ADM5 = 7 : EXIT-EDIT 0 16 LOCATE QUIT ; : ABORT-EDIT 0 15 LOCATE MESSAGE ; : BIND-ADDR ( C -- ADDR where binding is stored ) WORDSIZE * KEYMAP + ; --> ------------------ SCREEN 12 ------------------ ( EDITOR -- SCREEN 3 OF 19 -- I/O ) : ^EMIT ( OUTPUT W/ESC AND ^ ) DUP 127 > IF ." ESC-" 128 - THEN DUP 32 < IF ." ^" 64 + THEN EMIT ; : BACK-WRAP ( DECR EDIT SCR. AND PUT CURSOR AT BOTTOM ) EDIT-SCR -- C/L 1- COL ! 15 ROW ! 1 MUST-UPDATE ! ; : FORWARD-WRAP ( INCR EDIT SCR. AND PUT CURSOR AT TOP ) EDIT-SCR ++ 0 COL ! 0 ROW ! 1 MUST-UPDATE ! ; : ED-KEY ( INPUT W/ESC FOR HI BIT ) KEY DUP 27 = IF DROP KEY 128 + THEN DUP LAST-KEY-STRUCK ! ; --> ------------------ SCREEN 13 ------------------ ( EDITOR -- SCREEN 4 OF 19 -- BINDING WORDS ) : (BIND) ( CFA K -- STORES INTO KEYMAP ) BIND-ADDR ! ; : BIND-TO-KEY ( "BIND-TO-KEY NAME" ASKS FOR KEY ) [COMPILE] ' CFA ." KEY: " ED-KEY DUP ^EMIT SPACE (BIND) ; : DESCRIBE-KEY ." KEY: " ED-KEY DUP ^EMIT SPACE BIND-ADDR @ -DUP IF NFA ID. ELSE ." SELF-INSERT" THEN SPACE ; --> ------------------ SCREEN 14 ------------------ ( EDITOR -- SCREEN 5 OF 19 -- PRIMITIVE OPS ) : PREV-LINE ROW @ IF ROW -- 1 CURSOR-IS-DIRTY ! ELSE BACK-WRAP THEN ; : NEXT-LINE ROW @ 15 < IF ROW ++ 1 CURSOR-IS-DIRTY ! ELSE FORWARD-WRAP THEN ; : BEGINNING-OF-LINE 0 COL ! 1 CURSOR-IS-DIRTY ! ; : END-OF-LINE C/L 1- COL ! 1 CURSOR-IS-DIRTY ! ; : EDIT-CR NEXT-LINE BEGINNING-OF-LINE ; : PREV-CHAR COL @ IF COL -- 1 CURSOR-IS-DIRTY ! ELSE END-OF-LINE PREV-LINE THEN ; : NEXT-CHAR COL @ C/L 1- < IF COL ++ 1 CURSOR-IS-DIRTY ! ELSE EDIT-CR THEN ; --> ------------------ SCREEN 15 ------------------ ( EDITOR -- SCREEN 6 OF 19 -- MORE LOW-LEVEL ) : THIS-CHAR ROW @ EDIT-SCR @ (LINE) DROP COL @ + ; : PUT-CHAR THIS-CHAR C! 1 MUST-UPDATE ! ; : INSERT-CHAR PUT-CHAR NEXT-CHAR ; : SELF-INSERT LAST-KEY-STRUCK @ DUP THIS-CHAR C! EMIT NEXT-CHAR ; DECIMAL --> ------------------ SCREEN 16 ------------------ ( EDITOR -- SCREEN 7 OF 19 -- DISPLAY STUFF ) HEX : SHOWSCR ( N -- SHOWS SCREEN N ) CLS 0 10 LOCATE STANDOUT ." SCREEN " DUP . STANDEND 10 0 DO 0 I LOCATE I OVER .LINE LOOP DROP ; : REDRAW EDIT-SCR @ SHOWSCR ; : ?REDRAW MUST-UPDATE @ IF REDRAW 0 MUST-UPDATE ! 1 CURSOR-IS-DIRTY ! THEN ; DECIMAL --> ------------------ SCREEN 17 ------------------ ( EDITOR -- SCREEN 8 OF 19 -- EXECUTE-KEY ) : EXECUTE-KEY ( K -- EXECUTE THE KEY ) WORDSIZE * KEYMAP + @ -DUP IF EXECUTE ELSE SELF-INSERT THEN ; : ?PLACE-CURSOR CURSOR-IS-DIRTY @ IF COL @ ROW @ LOCATE 0 CURSOR-IS-DIRTY ! THEN ; --> ------------------ SCREEN 18 ------------------ ( EDITOR -- SCREEN 9 OF 19 -- TOP-LEVEL ) : TOP-LEVEL BEGIN ?REDRAW ?PLACE-CURSOR ED-KEY EXECUTE-KEY AGAIN ; : EDIT EDIT-SCR ! CLS 0 ROW ! 0 COL ! 1 MUST-UPDATE ! TOP-LEVEL ; --> ------------------ SCREEN 19 ------------------ ( EDITOR -- SCREEN 10 OF 19 -- HIGH-LEVEL KEY WORDS ) : UPDATE-SCR ( BOUND TO ^U ) EDIT-SCR @ B/SCR * DUP B/SCR + SWAP DO I BLOCK DROP UPDATE LOOP ; : NEXT-SCR ( ^C and ESC-C ) EDIT-SCR ++ 1 MUST-UPDATE ! ; : PREV-SCR ( ^R and ESC-R ) EDIT-SCR @ 0= IF EDIT-SCR ++ THEN EDIT-SCR -- 1 MUST-UPDATE ! ; --> ------------------ SCREEN 20 ------------------ ( EDITOR -- SCREEN 11 OF 19 -- HIGH-LEVEL ) HEX : TAB-KEY ( INCREMENT TO NEXT TAB STOP ) COL @ 8 + F8 AND DUP C/L < IF COL ! THEN ; DECIMAL : REEDIT ( RESTART EDITING ) EDIT-SCR @ EDIT ; : ERRCONV ERRBLK @ DUP B/SCR / SWAP B/SCR MOD DUP + ERRIN @ C/L @ / + ; : ERREDIT ERRCONV ROW ! EDIT-SCR ! BEGINNING-OF-LINE 1 MUST-UPDATE ! CLS TOP-LEVEL ; --> ------------------ SCREEN 21 ------------------ ( EDITOR -- SCREEN 12 OF 19 -- ) : UPDATE-AND-FLUSH UPDATE-SCR FLUSH ; : DEL-TO-END-OF-LINE COL @ ROW @ EDIT-SCR @ ( SAVE THESE ) C/L COL @ DO BL INSERT-CHAR LOOP EDIT-SCR ! ROW ! COL ! ( RESTORE SAVED VALUES ) ; --> ------------------ SCREEN 22 ------------------ ( EDITOR -- SCREEN 13 OF 19 -- MORE HIGH-LEVEL ) : CLEAR-SCREEN EDIT-SCR @ B/SCR * DUP B/SCR + SWAP DO I BLOCK B/BUF BLANKS LOOP 1 MUST-UPDATE ! ; : DESCRIBE-BINDINGS ( SHOWS ALL BINDINGS ) 256 0 DO ( INTERESTING ONES, ANYWAY ) I BIND-ADDR @ -DUP IF CR I ^EMIT SPACE NFA ID. THEN ?TERMINAL IF LEAVE THEN LOOP CR ; --> ------------------ SCREEN 23 ------------------ ( EDITOR -- SCREEN 14 OF 19 -- WORD MOVEMENT ) : NEXT-WORD THIS-CHAR C@ BL = IF PREV-CHAR THEN ( BUG FIX ) BEGIN NEXT-CHAR THIS-CHAR C@ BL = UNTIL BEGIN NEXT-CHAR THIS-CHAR C@ BL <> UNTIL ; : PREV-WORD BEGIN PREV-CHAR THIS-CHAR C@ BL <> UNTIL BEGIN PREV-CHAR THIS-CHAR C@ BL = UNTIL NEXT-CHAR ; --> ------------------ SCREEN 24 ------------------ ( EDITOR -- SCREEN 15 OF 19 -- BUFFER CONTROL ) : TO-BUFFER ( COPY FROM HERE TO BUFFER ) EDIT-SCR @ 16 0 DO I OVER (LINE) I C/L * SCR-BUFFER + SWAP CMOVE LOOP DROP ; : FROM-BUFFER ( COPY FROM BUFFER TO HERE ) EDIT-SCR @ 16 0 DO I OVER (LINE) DROP I C/L * SCR-BUFFER + SWAP C/L CMOVE LOOP DROP 1 MUST-UPDATE ! ; --> ------------------ SCREEN 25 ------------------ ( EDITOR -- SCREEN 16 OF 19 -- MORE BUFFERS ) : SCR-COPY ( SRC DEST -- COPIES A SCREEN ) EDIT-SCR @ ROT ROT ( OLD IS THIRD ) SWAP EDIT-SCR ! TO-BUFFER ( OLD IS SECOND/DEST IS FIRST ) EDIT-SCR ! FROM-BUFFER UPDATE-SCR EDIT-SCR ! ; : QUOTE-NEXT ED-KEY INSERT-CHAR ; : EXECUTE-FORTH-LINE 0 17 LOCATE 27 EMIT 84 EMIT REFORTH 1 MUST-UPDATE ! TOP-LEVEL ; --> ------------------ SCREEN 26 ------------------ ( EDITOR -- SCREEN 17 OF 19 -- ) --> ------------------ SCREEN 27 ------------------ ( EDITOR -- SCREEN 18 OF 19 -- INITIALIZE BINDINGS ) ' PREV-LINE CFA 11 (BIND) ( ^K ) ' NEXT-LINE CFA 10 (BIND) ( ^J ) ' PREV-CHAR CFA 8 (BIND) ( ^H ) ' NEXT-CHAR CFA 12 (BIND) ( ^L ) ' NEXT-SCR CFA 3 (BIND) ( ^C ) ' PREV-SCR CFA 18 (BIND) ( ^R ) ' EXIT-EDIT CFA 209 (BIND) ( ESC-Q ) ' EDIT-CR CFA 13 (BIND) ( ^M ) ' TAB-KEY CFA 9 (BIND) ( ^I ) ' UPDATE-SCR CFA 21 (BIND) ( ^U ) ' NEXT-WORD CFA 6 (BIND) ( ^F ) ' PREV-WORD CFA 1 (BIND) ( ^A ) ' UPDATE-AND-FLUSH CFA 198 (BIND) ( ESC-F ) --> ------------------ SCREEN 28 ------------------ ( EDITOR -- SCREEN 19 OF 19 -- MORE BINDINGS ) ' DEL-TO-END-OF-LINE CFA 25 (BIND) ( ^Y ) ' PREV-CHAR CFA 19 (BIND) ( ^S ) ' PREV-LINE CFA 5 (BIND) ( ^E ) ' NEXT-LINE CFA 24 (BIND) ( ^X ) ' NEXT-CHAR CFA 4 (BIND) ( ^D ) ' TO-BUFFER CFA 190 (BIND) ( ESC-> ) ' FROM-BUFFER CFA 188 (BIND) ( ESC-< ) ' NEXT-SCREEN CFA 195 (BIND) ( ESC-C ) ' PREV-SCREEN CFA 210 (BIND) ( ESC-R ) ' QUOTE-NEXT CFA 16 (BIND) ( ^P ) ' EXECUTE-FORTH-LINE CFA 155 (BIND) ( ESC-ESC ) CR ." EDITOR READY " ;S ------------------ SCREEN 29 ------------------ //go.sysin dd *