davidgiven · davidgiven · Aug 8, 2025 · Aug 7, 2025 · Aug 7, 2025 · Aug 7, 2025
diff --git a/README.md b/README.md
@@ -585,6 +585,43 @@ website](http://pascal.hansotten.com/px-descendants/pascal-m/pascal-m-2k1/).
 However, do not report bugs on the CP/M-65 port to him --- [file bug reports
 here](https://github.com/davidgiven/cpm65/issues/new) instead.
 
+### The Forth
+
+lbForth is a minimal Forth implementation but still contains a fair amount of
+built in words. It is currently not included on the disks for the C64, VIC20 
+or BBC Micro due to lack of disk space.
+
+The original source code is available [here](https://gist.github.com/lbruder/10007431). 
+
+It has been extended with the possibility to load a script from file at 
+startup if the filename is given as a command line argument, and a small
+example file (`TRIANGLE.FRT`) is included:
+```
+: STAR 42 EMIT ;
+: STARS 0 DO STAR LOOP ;
+: TRIANGLE 1 + 1 DO I STARS CR LOOP ;
+CR 10 TRIANGLE CR
+```
+When run from the command line it produces the following output:
+```
+A> LBFORTH TRIANGLE.FRT
+lbForth for CP/M-65. Use BYE to exit.
+
+*
+**
+***
+****
+*****
+******
+*******
+********
+*********
+**********
+
+END OF FILE
+ OK
+```
+
 ### Utilities
 
 `bin/cpmemu` contains a basic CP/M-65 user mode emulator and debugger. It'll run
@@ -645,3 +682,6 @@ and is available under the terms of the BSD 2-Clause License. See
 `third_party/zmalloc` contains a copy of zmalloc, which is © 2024 by Ivo van
 Poorten and is available under the terms of the 0BSD License. See
 `third_party/zmalloc/LICENSE` for the full text.
+
+`third_party/lbforth` contains a port of lbForth, which is © 2014 by Leif Bruder 
+and is released as Public Domain.
diff --git a/config.py b/config.py
@@ -66,6 +66,11 @@
     "0:hello.pas": "cpmfs+hello_pas_cpm",
 }
 
+FORTH_APPS = {
+    "0:lbforth.com": "third_party/lbforth",
+    "0:triangle.frt": "cpmfs+triangle_frt_cpm",
+}
+
 SERIAL_APPS = {
     "0:xrecv.com": "apps+xrecv",
     "0:xsend.com": "apps+xsend",

diff --git a/cpmfs/build.py b/cpmfs/build.py
@@ -6,3 +6,4 @@
 unixtocpm(name="demo_sub_cpm", src="./demo.sub")
 unixtocpm(name="hello_asm_cpm", src="./hello.asm")
 unixtocpm(name="hello_pas_cpm", src="./hello.pas")
+unixtocpm(name="triangle_frt_cpm", src="./triangle.frt")
diff --git a/cpmfs/triangle.frt b/cpmfs/triangle.frt
@@ -0,0 +1,5 @@
+: STAR 42 EMIT ;
+: STARS 0 DO STAR LOOP ;
+: TRIANGLE 1 + 1 DO I STARS CR LOOP ;
+CR 10 TRIANGLE CR
+
diff --git a/src/arch/apple2e/build.py b/src/arch/apple2e/build.py
@@ -9,6 +9,7 @@
     SCREEN_APPS_SRCS,
     BIG_SCREEN_APPS,
     PASCAL_APPS,
+    FORTH_APPS,
 )
 
 llvmcfile(
@@ -71,7 +72,8 @@
     format="appleiie",
     bootimage=".+bios_shuffled",
     size=143360,
-    items={} | SCREEN_APPS | SCREEN_APPS_SRCS | BIG_SCREEN_APPS | PASCAL_APPS,
+    items={} | SCREEN_APPS | SCREEN_APPS_SRCS | BIG_SCREEN_APPS | PASCAL_APPS
+             | FORTH_APPS,
 )
 
 

diff --git a/src/arch/atari800/build.py b/src/arch/atari800/build.py
@@ -10,6 +10,7 @@
     SCREEN_APPS_SRCS,
     BIG_SCREEN_APPS,
     PASCAL_APPS,
+    FORTH_APPS,
 )
 
 llvmclibrary(name="headers", hdrs={"atari800.inc": "./atari800.inc"})
@@ -70,7 +71,8 @@
     name="atari800c_rawdiskimage",
     format="atari90",
     size=128 * 720,
-    items={} | MINIMAL_APPS_SRCS | SCREEN_APPS_SRCS | BIG_APPS_SRCS,
+    items={} | MINIMAL_APPS_SRCS | SCREEN_APPS_SRCS | BIG_APPS_SRCS 
+             | FORTH_APPS,
 )
 
 simplerule(
@@ -119,7 +121,8 @@
     | SCREEN_APPS
     | SCREEN_APPS_SRCS
     | BIG_SCREEN_APPS
-    | PASCAL_APPS,
+    | PASCAL_APPS
+    | FORTH_APPS,
 )
 
 simplerule(
@@ -168,7 +171,8 @@
     | SCREEN_APPS
     | SCREEN_APPS_SRCS
     | BIG_SCREEN_APPS
-    | PASCAL_APPS,
+    | PASCAL_APPS
+    | FORTH_APPS,
 )
 
 simplerule(

diff --git a/src/arch/kim-1/build.py b/src/arch/kim-1/build.py
@@ -10,6 +10,7 @@
     SCREEN_APPS,
     BIG_SCREEN_APPS,
     PASCAL_APPS,
+    FORTH_APPS,
 )
 
 COMMODORE_ITEMS = (
@@ -126,7 +127,8 @@
     | BIG_APPS_SRCS
     | SCREEN_APPS
     | BIG_SCREEN_APPS
-    | PASCAL_APPS,
+    | PASCAL_APPS
+    | FORTH_APPS,
 )
 
 mkcpmfs(
@@ -146,7 +148,8 @@
     | BIG_APPS_SRCS
     | SCREEN_APPS
     | BIG_SCREEN_APPS
-    | PASCAL_APPS,
+    | PASCAL_APPS
+    | FORTH_APPS,
 )
 
 mkcpmfs(
@@ -169,7 +172,8 @@
     | BIG_APPS_SRCS
     | SCREEN_APPS
     | BIG_SCREEN_APPS
-    | PASCAL_APPS,
+    | PASCAL_APPS
+    | FORTH_APPS,
 )
 
 mkimd(name="diskimage-k1013", src=".+rawdiskimage-k1013")

diff --git a/src/arch/nano6502/build.py b/src/arch/nano6502/build.py
@@ -11,6 +11,7 @@
     PASCAL_APPS,
     SERIAL_APPS,
     SERIAL_SCREEN_APPS,
+    FORTH_APPS,
 )
 
 llvmrawprogram(
@@ -38,7 +39,8 @@
     | BIG_SCREEN_APPS
     | PASCAL_APPS
     | SERIAL_APPS
-    | SERIAL_SCREEN_APPS,
+    | SERIAL_SCREEN_APPS
+    | FORTH_APPS,
 )
 
 mkcpmfs(

diff --git a/src/arch/neo6502/build.py b/src/arch/neo6502/build.py
@@ -11,6 +11,7 @@
     SCREEN_APPS_SRCS,
     BIG_SCREEN_APPS,
     PASCAL_APPS,
+    FORTH_APPS,
 )
 import re
 
@@ -78,6 +79,7 @@
             | SCREEN_APPS_SRCS
             | BIG_SCREEN_APPS
             | PASCAL_APPS
+            | FORTH_APPS
         ).items()
     },
 )
diff --git a/src/arch/oric/build.py b/src/arch/oric/build.py
@@ -9,6 +9,7 @@
     SCREEN_APPS_SRCS,
     BIG_SCREEN_APPS,
     PASCAL_APPS,
+    FORTH_APPS,
 )
 
 llvmcfile(
@@ -53,7 +54,8 @@
     | SCREEN_APPS
     | SCREEN_APPS_SRCS
     | BIG_SCREEN_APPS
-    | PASCAL_APPS,
+    | PASCAL_APPS
+    | FORTH_APPS,
 )
 
 mkoricdsk(name="diskimage", src=".+cpmfs")

diff --git a/src/arch/osi/build.py b/src/arch/osi/build.py
@@ -9,6 +9,7 @@
     SCREEN_APPS_SRCS,
     BIG_SCREEN_APPS,
     PASCAL_APPS,
+    FORTH_APPS,
 )
 
 # ----------------------------------------------------------------------------
@@ -114,7 +115,8 @@
     }
     | SCREEN_APPS
     | SCREEN_APPS_SRCS
-    | BIG_SCREEN_APPS,
+    | BIG_SCREEN_APPS
+    | FORTH_APPS,
 )
 
 img2osi(
@@ -204,7 +206,8 @@
     | BIG_APPS
     | PASCAL_APPS
     | MINIMAL_APPS_SRCS
-    | BIG_APPS_SRCS,
+    | BIG_APPS_SRCS
+    | FORTH_APPS,
 )
 
 mkcpmfs(
@@ -224,7 +227,8 @@
     | BIG_APPS_SRCS
     | SCREEN_APPS
     | SCREEN_APPS_SRCS
-    | BIG_SCREEN_APPS,
+    | BIG_SCREEN_APPS
+    | FORTH_APPS,
 )
 
 mkcpmfs(
@@ -241,7 +245,8 @@
     | BIG_APPS
     | PASCAL_APPS
     | MINIMAL_APPS_SRCS
-    | BIG_APPS_SRCS,
+    | BIG_APPS_SRCS
+    | FORTH_APPS,
 )
 
 mkcpmfs(name="osif-b_rawdiskimage", format="osi8", size=128 * 1848, items={})
@@ -299,7 +304,8 @@
     | BIG_APPS_SRCS
     | SCREEN_APPS
     | SCREEN_APPS_SRCS
-    | BIG_SCREEN_APPS,
+    | BIG_SCREEN_APPS
+    | FORTH_APPS,
 )
 
 img2osi(
@@ -351,7 +357,8 @@
     | MINIMAL_APPS_SRCS
     | BIG_APPS_SRCS
     | SCREEN_APPS_SRCS
-    | BIG_SCREEN_APPS,
+    | BIG_SCREEN_APPS
+    | FORTH_APPS,
 )
 
 mkcpmfs(

diff --git a/src/arch/snes/build.py b/src/arch/snes/build.py
@@ -10,6 +10,7 @@
     SCREEN_APPS,
     BIG_SCREEN_APPS,
     PASCAL_APPS,
+    FORTH_APPS,
 )
 
 llvmrawprogram(
@@ -36,7 +37,8 @@
     | BIG_APPS
     | SCREEN_APPS
     | BIG_SCREEN_APPS
-    | PASCAL_APPS,
+    | PASCAL_APPS
+    | FORTH_APPS,
 )
 
 simplerule(

diff --git a/src/arch/sorbus/build.py b/src/arch/sorbus/build.py
@@ -9,6 +9,7 @@
     BIG_APPS_SRCS,
     PASCAL_APPS,
     SERIAL_APPS,
+    FORTH_APPS,
 )
 
 llvmrawprogram(
@@ -27,7 +28,8 @@
     | BIG_APPS
     | BIG_APPS_SRCS
     | PASCAL_APPS
-    | SERIAL_APPS,
+    | SERIAL_APPS
+    | FORTH_APPS,
 )
 
 zip(

diff --git a/src/arch/x16/build.py b/src/arch/x16/build.py
@@ -8,6 +8,7 @@
     BIG_APPS,
     BIG_APPS_SRCS,
     PASCAL_APPS,
+    FORTH_APPS,
 )
 
 llvmrawprogram(
@@ -25,7 +26,8 @@
     | MINIMAL_APPS_SRCS
     | BIG_APPS
     | BIG_APPS_SRCS
-    | PASCAL_APPS,
+    | PASCAL_APPS
+    | FORTH_APPS,
 )
 
 zip(

diff --git a/third_party/lbforth/build.py b/third_party/lbforth/build.py
@@ -0,0 +1,9 @@
+from build.ab import Rule, Target, Targets, simplerule
+from build.llvm import llvmprogram
+from tools.build import unixtocpm
+
+llvmprogram(
+    name="lbforth",
+    srcs=["./lbforth.c"],
+    deps=["lib+cpm65"],
+)