electro·pizza — defMON, VICE, and the Pocket CHIP (2019)

A 2019-07-29 blog post by Ryan Oles documenting, step by step, how he set up vice on a Pocket CHIP (a small Debian-based handheld with a keyboard) to practice defmon without dedicating desk space to a real commodore-64 — including the exact VICE settings that make defMON usable and the keyboard mappings that are not obvious. He found defMON through goto80's recordings and live sets: "The sounds he is able to tease out of the Commodore's SID chip are unlike most C64 music I have heard."

Key claims#

• What defMON is (as seen from outside): "a bit unique in that it does not use references across many tables, as most C64 sound editors do, but rather a single flexible instruments and effects table"; under "semi-active development — its most recent release is from November of 2018 (as of this writing)", which the author calls a rarity for software on ~40-year-old hardware.
• Installing VICE on Debian-family Linux (Pocket CHIP): sudo apt install vice installs the emulator without the C64 system ROM (copyright); the fix is to download the full source tarball (vice-3.3.tar.gz from zimmers.net), extract it, and sudo cp -rv vice-3.3/data/C64/* /usr/lib/vice/C64/. Verify with x64 and wait for the blue Ready screen; quit with alt+q.
• VICE settings that matter for defMON (Settings menu; alt+b toggles the menu bar, alt+d toggles fullscreen; save settings before exiting):
  • VIC-II: disable "Hardware scaling" (required), disable "Double size" (required), Render Filter "Unfiltered", enable fullscreen.
  • Sound: device "alsa" (required), output mode "Stereo", sample rate lowered to 22050 Hz ("playback seems smoothest at this rate"), sound playback enabled.
  • Drive: disable "Drive sound emulation".
  • Alternatively drop the author's ready-made config over ~/.vice/vicerc.
• Keyboard gotchas: VICE's default symbolic keymap is mostly intuitive, but four C64 keys hide behind modern keys: ← (top-left arrow key) = _ (underscore), ctrl = tab, Run/Stop = esc, C= = ctrl.
• Getting and running defMON: download the latest zip from the defMON wiki (at the time defmon-20181101.zip from toolsforscholars.com), unzip, and start it directly from the shell: x64 ~/src/c64/defmon/defmon-20181101.d64 — more convenient than attaching the disk image through the GUI. On the Pocket CHIP he adds a homepage-launcher entry in /usr/share/pocket-home/config.json whose shell runs that same command.
• Verdict on emulated defMON: sound is good "but not as good as running this on an actual SID chip"; audio hiccups on complex tracks; defMON's key commands "make a lot of sense on a Commodore 64, but not so much when they are mapped to a modern keyboard layout" — so not recommended for live performance or long in-depth work, but "an excellent way to get more familiar with how to use defMON", "especially useful in experimenting with and constructing instruments and effects in the SID tab".

Practical takeaways#

• The minimum viable defMON-in-VICE recipe: real C64 ROMs in place, ALSA (or the platform equivalent) as sound device, filtering/scaling off on weak hardware, drive sounds off, then x64 <defmon>.d64 from the command line.
• Learn the symbolic-keymap translations before blaming defMON: on a PC keyboard ← is _, ctrl is tab, Run/Stop is esc and C= is ctrl.
• Emulation is a practice and sound-design environment (the SID tab), not a performance rig — the same division of labour goto80 implies by playing live on real hardware (compare the "fuck emulators" stance in s-remix64-goto80-interview).

Notable quotes#

• "The sounds he is able to tease out of the Commodore's SID chip are unlike most C64 music I have heard, making me very curious about this esoteric application." (on goto80)
• "It is an excellent way to get more familiar with how to use defMON, and is proving especially useful in experimenting with and constructing instruments and effects in the SID tab."

Relevance to the wiki#

First hands-on source for the modern defMON setup workflow: it pins a concrete release (2018-11-01), describes the one-table design from a user's viewpoint, and supplies the VICE configuration and keymap table any defmon cheat sheet should carry for emulator users.

Pages touched#

defmon · vice · goto80 · sid · commodore-64