From aec19e5c8756a0e73203cb9ecb8a3f04e1d7ad2d Mon Sep 17 00:00:00 2001
From: Virgil Dupras <hsoft@hardcoded.net>
Date: Tue, 14 Apr 2020 18:15:07 -0400
Subject: [PATCH] Add word "LOAD"

---
 blk/001             |   2 +-
 blk/064             |   1 +
 blk/100             |  10 ++++++++++
 blk/102             |   2 ++
 emul/forth/z80c.bin | Bin 2190 -> 2196 bytes
 forth/blk.fs        |  30 ++++++++++++++++++++++++++++--
 forth/icore.fs      |   4 ++--
 7 files changed, 44 insertions(+), 5 deletions(-)
 create mode 100644 blk/100
 create mode 100644 blk/102

diff --git a/blk/001 b/blk/001
index d1c46bb..0151c8e 100644
--- a/blk/001
+++ b/blk/001
@@ -1,4 +1,4 @@
 MASTER INDEX
 
   3 Usage                      30 Dictionary
- 70 Implementation notes
+ 70 Implementation notes      100 Block explorer
diff --git a/blk/064 b/blk/064
index 8b2e2f7..b67c882 100644
--- a/blk/064
+++ b/blk/064
@@ -3,3 +3,4 @@ Disk
 BLK> -- a Address of the current block variable.
 LIST n -- Prints the contents of the block n on screen in the
           form of 16 lines of 64 columns.
+LOAD n -- Interprets Forth code from block n
diff --git a/blk/100 b/blk/100
new file mode 100644
index 0000000..8680085
--- /dev/null
+++ b/blk/100
@@ -0,0 +1,10 @@
+Block explorer
+
+This is an application to conveniently browse the contents of
+the disk blocks. You can launch it with "102 LOAD".
+
+USAGE: When loaded, the Forth interpreter is replaced by the
+explorer interpreter. Typing "Q" quits the program.
+
+Typing a decimal number followed by space or return lists the
+contents of that block.
diff --git a/blk/102 b/blk/102
new file mode 100644
index 0000000..6e9ec68
--- /dev/null
+++ b/blk/102
@@ -0,0 +1,2 @@
+: foo ." Hello world! " 42 . ;
+foo
diff --git a/emul/forth/z80c.bin b/emul/forth/z80c.bin
index 3f44d696afa0acd7230c97cf0ff774d0a8a2f1ec..5efc075d11ca13cee1ae76d027cd491d9efc998d 100644
GIT binary patch
delta 73
zcmeAZoFcfPpPe%)KflCA)0lyM@>KQ^77%apD|Q{m*vaA?!73&k1q>Vv{R|NdEDR28
b5e!@mJ6OD!`x)dpA{cJ{cV>t;WncsV>)jG)

delta 49
zcmbOt*eAH5pPen)M$>?SW%3O65XR)mAJ}ymqbAF81T*SQF60pBk>rSAxb@$eA>NdM
F5dc|(4I2Oe

diff --git a/forth/blk.fs b/forth/blk.fs
index c64ed6c..04750e3 100644
--- a/forth/blk.fs
+++ b/forth/blk.fs
@@ -7,11 +7,17 @@
 : BLK!* 2 BLKMEM+ ;
 ( Current blk pointer in ( )
 : BLK> 4 BLKMEM+ ;
-: BLK( 6 BLKMEM+ ;
+( backup for CINPTR when LOADing )
+: BLKC<* 6 BLKMEM+ ;
+: BLK( 8 BLKMEM+ ;
 
 : BLK$
     H@ 0x57 RAM+ !
-    1030 ALLOT
+    ( 1024 for the block, 8 for variables )
+    1032 ALLOT
+    ( LOAD detects end of block with ASCII EOT. This is why
+      we write it there. EOT == 0x04 )
+    4 C,
     -1 BLK> !
 ;
 
@@ -30,3 +36,23 @@
         CRLF
     LOOP
 ;
+
+: _
+    (boot<)
+    DUP 4 = IF
+        DROP
+        ( We're finished interpreting )
+        BLKC<* @ 0x0c RAM+ !
+        C<
+    THEN
+;
+
+: LOAD
+    BLK@
+    ( 2e == BOOT C< PTR )
+    BLK( 0x2e RAM+ !
+    ( Save current C< ptr )
+    0x0c RAM+ @ BLKC<* !
+    ( 0c == CINPTR )
+    ['] _ 0x0c RAM+ !
+;
diff --git a/forth/icore.fs b/forth/icore.fs
index 58872e2..2cd62f7 100644
--- a/forth/icore.fs
+++ b/forth/icore.fs
@@ -178,7 +178,7 @@
 
 ( system c< simply reads source from binary, starting at
   LATEST. Convenient way to bootstrap a new system. )
-: (c<)
+: (boot<)
     ( 2e == BOOT C< PTR )
     0x2e RAM+ @   ( a )
     DUP C@        ( a c )
@@ -192,7 +192,7 @@
     ( 2e == SYSTEM SCRATCHPAD )
     CURRENT @ 0x2e RAM+ !
     ( 0c == CINPTR )
-    LIT< (c<) (find) DROP 0x0c RAM+ !
+    LIT< (boot<) (find) DROP 0x0c RAM+ !
     LIT< INIT (find)
     IF EXECUTE
     ELSE DROP INTERPRET THEN