Siddasm v2.1 (sid, sap and nsf disassembler) win32/win64 binaries
siddasm siddasm2 sid sap nsf disassembler binaries
I just cross-compiled these from within Debian Linux (wheezy) and instead of only sharing them with the person I did this for, I thought I might just as well share them with everybody. Source code (GPL) is included. The win32 binary has been tested to work with wine under Linux. I cannot test the win64 binary, but it should work as well. Note that this is a command line utility. siddasm2.exe input.sid > output.asm. The output is in atasm format. It takes NSF (NES) and SAP (Atari 8-bit) files as well. Sid files need to be PSID. RSID is not yet supported.
Edit [2015-07-17]: Updated to v2.2, hopefully fixed /dev/null issue on windows.
Edit2: added source code.