A repository of bug-fixed and patched software projects for DEC PDP-11 systems, targeting real hardware, SimH, and PiDP-11 emulators running RT-11 and RSX-11M-PLUS. The two main projects are FIG-FORTH v1.4, which corrects garbled terminal output and a corrupted screen file, and FOCAL-11 V11-01C, which fixes an infinite recursion crash in the FEXP function.
- FIG-FORTH originally marked dictionary names with a high bit that modern terminals rendered as a literal "?" character; the patch strips it before display without affecting the dictionary
- The FORTH.DAT file was distributed with a VARIABLE RMS record format, embedding 2-byte length headers every 512 bytes that appeared as stray characters in screens
- FOCAL-11's XFEXP computed e^x by recursively halving the exponent until it fell below -8, but zero's exponent never decreases, so the recursion ran the stack into memory; all other math functions already had a depth guard
- FOCAL is a BASIC-like language from the late 1960s; Lunar Lander was originally written in it
- FIG-FORTH originally marked dictionary names with a high bit that modern terminals rendered as a literal "?" character; the patch strips it before display without affecting the dictionary
- The FORTH.DAT file was distributed with a VARIABLE RMS record format, embedding 2-byte length headers every 512 bytes that appeared as stray characters in screens
- FOCAL-11's XFEXP computed e^x by recursively halving the exponent until it fell below -8, but zero's exponent never decreases, so the recursion ran the stack into memory; all other math functions already had a depth guard
- FOCAL is a BASIC-like language from the late 1960s; Lunar Lander was originally written in it
