diff --git a/src/toolsrc/codegen.pla b/src/toolsrc/codegen.pla
index 229382e..2e297d2 100644
--- a/src/toolsrc/codegen.pla
+++ b/src/toolsrc/codegen.pla
@@ -565,8 +565,9 @@ def init_idglobal#0
         dfd_num     = DFDNUM/2
         tag_num     = TAGNUM/2
         fixup_num   = FIXUPNUM/2
-        globalbufsz = IDGLOBALSZ
+        globalbufsz = IDGLOBALSZ/2
         localbufsz  = IDLOCALSZ/2
+	inbuff_len  = MAX_INPUT_LEN/2
     fin
     //
     //Init free op sequence list
diff --git a/src/toolsrc/lex.pla b/src/toolsrc/lex.pla
index e6f9e60..877a631 100644
--- a/src/toolsrc/lex.pla
+++ b/src/toolsrc/lex.pla
@@ -340,14 +340,14 @@ def nextln
         fin
         if token == CNT_TKN
           inptr = scanptr
-          inlen = MAX_INPUT_LEN - (inptr - inbuff)
+          inlen = inbuff_len - (inptr - inbuff)
           if inlen <= 0
             puts("Input "); exit_err(ERR_OVER)
           fin
         else
           scanptr = inbuff
           inptr   = inbuff
-          inlen   = MAX_INPUT_LEN
+          inlen   = inbuff_len
         fin
         inlen = fileio:read(refnum, inptr, inlen)
         if inlen
diff --git a/src/toolsrc/plasm.pla b/src/toolsrc/plasm.pla
index 7257972..14e5e12 100755
--- a/src/toolsrc/plasm.pla
+++ b/src/toolsrc/plasm.pla
@@ -284,10 +284,10 @@ word srcline              // Saved source line number
 //
 // Scanner variables
 //
-const MAX_INPUT_LEN   = 1024
-word inbuff
+const MAX_INPUT_LEN     = 1024
+word inbuff, inbuff_len = MAX_INPUT_LEN
 word scanptr
-byte token             = EOL_TKN
+byte token              = EOL_TKN
 byte scanchr, tknlen
 word tknptr, parserrln
 word constval
@@ -582,7 +582,8 @@ if srcfile and relfile
         refnum       = srcref
         parsefile    = @srcfile
         strconstbuff = heapalloc(80)
-        inbuff       = heapalloc(MAX_INPUT_LEN)
+	if isult(heapavail, $6000); inbuff_len = MAX_INPUT_LEN/2; fin
+        inbuff       = heapalloc(inbuff_len)
         scanptr      = inbuff
         ^inbuff      = NULL
         exit         = heapalloc(t_except)