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Disclaimer: I am not responsible for what people (other than myself) write in the forums. Please report any abuse, such as insults, slander, spam and illegal material, and I will take appropriate actions. Don't feed the trolls.

Jag tar inget ansvar för det som skrivs i forumet, förutom mina egna inlägg. Vänligen rapportera alla inlägg som bryter mot reglerna, så ska jag se vad jag kan göra. Som regelbrott räknas till exempel förolämpningar, förtal, spam och olagligt material. Mata inte trålarna.

Apr 2011

The Chipophone

Sat 2-Apr-2011 00:04
I need this thing. I need it in my house. Please make more and sell them, I'll gladly pay for the cost of the organ as well as labor to modify it.

Making the Chipophone

Sun 3-Apr-2011 21:39
Fan va coolt! :D

Reliable synchronisation of cog PLLs

Wed 6-Apr-2011 11:14

The reason I did a "mov vscl,#100" while the video generator was reloading on each pixel clock was to hand it a vscl value, which would be grabbed immediately, which would occupy the video shifter until the user-chosen vscl values and waitvid instructions were ready to go in each cog. It just puts the initial important reload 100 pixels out, so there's time for each cog to set its own initial vscl value and get into its own waitvid before it's show-time. I agree there could be some synchronization problem on issuance of the vscl=100, but if that is synchronous across all cogs, all subsequent waitvids should be forever sync'd. It might have been my dumb luck that the FRQ values I was using never got me near a metastability point that could have caused the "mov vscl,#100" to not take across all cogs simultaneously.

Have you witnessed any synchronization problems with any of the multi-cog video drivers that I wrote? I haven't, myself, and I've never heard anyone else say so. I'm just curious.

I really liked that Turbulence demo you wrote. I hope you stay interested in the Propeller, as the next version has perspective-corrected texture mapping with RGB lighting and alpha-blending, all in 8:8:8 RGB. There's also a lot of math hardware for fast transcedentals. You would be able to make it do lots, I know. It has 75-ohm 9-bit DACs on every pin, too, so you get nice video. You can attach an SDRAM for big memory (APA graphics), as well.


Chip Gracey
Parallax, Inc.

A case against syntax highlighting

Wed 6-Apr-2011 20:11
In the prose example, White should be green like all the other adjectives. Just saying - being the proofreader I am. http://jcoud.com :)

The TTY demystified

Mon 11-Apr-2011 18:08
ZZZZZZZZZZZZZZZZZZZZZZZZZZ to long, jesus christ write up a summery for us lazy people
if(easilyBored || notInterested){
} else {
try {
catch(DontUnderstandException dde){
finally {

The Chipophone

Sat 16-Apr-2011 06:10
i whant to make one but in a old keybourd like this one i have,
Casio casiotone mt-100
Thu 21-Apr-2011 00:09
Just wanted to say I really love your instrument, and please keep on releasing new tunes :-) Have been listening for hours now..
However I have a question to the following reply from you:

lft wrote:

The shift register is global, so I never use r8 or r9 for anything else. This makes the code very efficient. I could probably make it even faster, but right now the triangle wave is the bottleneck.

Why is the triangle generator your bottleneck? It seems simple enough; just left shift the current waveform counter value by one, and in case of a carry bit, xor the result.

BTW: I would really love to see the code for the synth module :-)

- Johnny
Thu 21-Apr-2011 00:11
Sorry, I meant invert the result (xor by 1's). - Johnny

Still Alive

Thu 21-Apr-2011 14:14
Win! :)


Fri 22-Apr-2011 06:51
This is an interesting analysis. Very intriguing!

I think that the "circular" step-wise motion is an effect, not a cause. I believe that the voices move that way due to the smooth, scalar voice-leading that Part chose; but I do not believe that Part was thinking in the way that you describe: which is to say that the music can certainly be diagrammed in the manner that you describe, but that I do not believe that Part had this scheme in his head when he composed the piece. Certainly, there is a harmonic additive process being employed. But I think that he was thinking in harmony, melody, and voice-leading.

Of course, I don't know that for a fact, and again I don't mean to criticize your analysis--only to point out that perhaps Part was thinking in "math," from which you have distilled an interesting "equation."

Beagleboard VGA output

Tue 26-Apr-2011 19:23

Andre wrote:

Hi, i'm the Anonymous from Wed 20-Jan-2010 10:42.

I just got my VGA converter ready and it seems to work great. The picture on the VGA side has some top rows on the bottom even after i adjusted the monitor(quite old nokia 500 Xa LCD monitor). The colors seem ok(the orange angstrom logo and the blue text), though i haven't had any full color pictures up yet, so don't know about the graduated colors, that TrevJ commented about. I have both VGA and DVI on(straight HMDI cable to a TV).

The schematic is fine. I added the DDC lines, 5V and 1,8V lines including voltage converters for the DDC lines on mine based on the sparkfun i2c level converter.

Just finished it like half an hour or so ago.

Thank you very much.

I have a question about the DDC lines. These are to return the monitor identification and information.
But what does the BeagleBoard do with the values. Will it auto-configure the display timings based on these values?

Also, if I look at these I will need to supply 5 volts on pin 9 http://pinouts.ru/Video/VGAVesaDdc_pinout.shtml
The SDA and SCL, are they supposed to be level shifted to 5 volts? Or what's their signal level supposed to be?

The VESA E-DDC specification specifies use of I2C at +5V.

About me

Wed 27-Apr-2011 22:01
Hi Linus,

Thank you for your great contribution to 8-bit music and SID-Chip compositions. If you should ever have any need for webdesign or webprograming just ask, and I'll gladly contribute. :-)

Have downloaded all your compositions and they are now site by site with the Lizardking and some of the other old SID-kings. ;-)

Metroid, part 2

Thu 28-Apr-2011 03:13
WOW...look at this. I love the chipophone! I visited your site many times, to listen to your tunes and they even made it into my car :) And suddenly there is a wonderful version of one of my favorite melodies.
Thank you so much!!!