SVGA 800×600 test pattern with a PIC16f84A microcontroller

here’s my first assembly language project in the works:

i started with the program from here: “”:

it didn’t work until i added the 555 part of “this circuit”: in order to get the V-synch pulse-width right.

this spurred a rewrite of the program. this synched without the extra PWM stuff…
i added an extra output to function as a gate to control a 4066 switch for proper RGB blanking.

everything worked fine in the middle of the screen,
but the top of the image was skewed:

rather than try to fix this,
i moved on to making an SVGA 800×600 @ 60Hz program based on the timing info found here: “×600@60Hz”:×600@60Hz (and some other details elsewhere)
this runs on a 20MHz crystal which, if you do the math = exactly 100 instructions / visible line and nice round numbers for all the sync and blanking periods.

for fun i followed up with a 1024×768 @ 60Hz version:

happily this program actually worked first try, however, the skewed image thing returned.
with a lot of tuning to the Vsync areas i minimized the skew to just a small bump at the top, but i’m not sure how portable this thing would be with less forgiving monitors.
for this version i also added 75ohm terminating resisters to the RGB outputs.

i’m thinking that the ratios between vertical and horizontal sync times have a lot to do with the skewing thing. so far, this last version looks just the same whether the the processor clock is running at 18, 20, or 17.7344 MHz.
the 800×600 version has at least all the correct ratios. so next step is to use this as the core of a new AV synth.

operation twins

this video is some excerpts from a live A/V synthesis session in 2008.
part of a series of practice tapes leading up to performances in vancouver and minneapolis.

the title “operation twins” comes from a fiction book written in the 1990’s by my studio neighbour which cover the role of simulation in international intelligence and espionage.



h5. “”:

h2. Wednesday 2nd of July 2008

h1. HalloGallo! #9

h3. SUNBURNED HAND OF THE MAN (Massachusetts, USA) *

Sunburned Hand of the Man are a band from Massachusetts that formed in 1997 from the remnants of the Boston psychedelic punk trio Shit Spangled Banner.
Sunburned Hand of the Man has an amorphous lineup, with composition and instrumentation potent

h3. BRIAN MCKENNA (Canada) *

analogue video synthesizer


Sweden’s finest elite no-wave fractured-folkists hit some sort of zero-gee post-Beefheart sauna-bar, swinging off creaking, badly-hung pine doors, inhaling steam and beer-fumes as they trigger every Casio pre-set imaginable and crank up their banjos to, u

€ 5,- Doors open 21.00

i’m playing a couple of live sets coming up:

april 19 in vancouver

and may 1 in minneapolis

modulated zips

here’s an improvised video,
made live,
with homemade electronics,
namely, 2 sound-generator/distorter-manglers,
an envelope-controlled state-variable-filter,
and a video-synthesizer… some audio mixers and lots of patch-cables also


in other related news,
the forum about,
building video-synthesizers,
which once lived here,
is back online:

blog comments are off because of spam


that’s all….

….oh, and it really seems like this year will be a new year.

Glen Gould: The Latecomers

My favourite example the “Contrapunctal Radio” style, this audio-piece about `Outport Newfoundland` from 1969 was actually the first CBC radio broadcast over their new stereo-network:


sequel to the idea of north, poetic test-pattern..
the fidelity would seem to encourage close, careful listening, perhaps with headphones, in an uniterupted space of time; as one should suppose music recordings would.