SyMa is a sound-patch editor for Yamaha Tx81z,  DX21/27/100, Casio MT260
and other simple synths. It uses GUI under MS-Windows 3.x.  Some screens
are slow - there are lot of controls (buttons, scrolls, lists) on every screen,
thus windows uses lot of cpu power to draw them!

Screen Shot

System Requirements
   - MS-Windows 3.0
   - Roland MPU-401 compatible midi adapter (e.g. MPU-IPC-T)
   - PC (386DL/SX...486 recommended)
   - Yamaha TX81Z  (should also work with DX21/27/100, but I've never
tested)
   - Casio MT-260 or another using PROGRAM CHANGE as voice selection.
   - mouse supported by windows
   - optional printer
   - disk space 400k