Hi, Richa Rd!
Yes, the TinyCore Xprogs (Control Panel, Apps and friends) unconditionally try to start aterm, and if You install st instead of aterm You can easily propose it instead of aterm for other TinyCore stuff members. For example place in Your ~/.local/bin directory (it is included in $PATH) the following file, named aterm and having execution permissions and redirecting to st:
cat > ~/.local/bin/aterm << EOF
#!/bin/sh
exec /usr/local/bin/st -f Fixed:pixelsize=15:style=bold "$@"
EOF
chmod +x ~/.local/bin/aterm
And all TinyCore programs will work well.
St has some pleasant features:
1. It don't deliver mouse events to the in-running programs.
2. It can deal with both X clipboard buffers. Ctrl-Shift-C and Ctrl-Shift-V for one of them and simply select with mouse and Shift-Ins for the other.
3. You can instantly adjust Your font size with Ctrl-Shift-PgUp and Ctrl-Shift-PgDn.
rxvt in no doubt is the champion. But for me st is favorite :-)
What options You were using to start showkey? In ascii mode (-a) it exits at Ctrl-D.