DJGPP source code can be obtained from <https://www.delorie.com/djgpp/>.

DJGPP toolchain has been built with
https://github.com/jwt27/build-gcc.git> branch master commit acfa07a8681004a676c552d538ed5833d7cfb65c
using DJGPP source code from
<https://github.com/jwt27/djgpp-cvs.git> branch jwt27 commit ca9f7dcd7a0a02d16b688f88d8b65d7dea93f69a
including Watt-32 source code from
<https://github.com/gvanem/Watt-32.git> branch master commit 62a887638c7a6cf7ba9807277d0753222b4d8ad8
.
