fluke

Half wave means that only 1 half of the AC waveform is being used. See http://en.wikipedia.org/wiki/Rectifier#Half-wave_rectification for a diagram and more details. You've got a "dual wave" power supply, which is 2 half wave power supplies, one taking the positive half of the wave and one taking the negative half. Each supply can only draw half the rated current of the transformer. It's also good to make sure that each half is drawing approximately the same current.

It's an SB Pro 2 on a single chip. An OPL3, plus digital sound, mixer, microphone inputs, etc.

I just used a standard IDE drive when i upgraded my iMac. Older versions of Mac OS did refuse partition non-Apple hard drives, iirc, but that's no longer the case. There were patches available for it to work with non-Apple drives.

Except that the first one is passing an int instead of a pointer to an int and will stop your program with a segmentation fault if you're lucky and overwrite random parts of memory if you're not. I definately agree with the idea of learning C on a PC first. There you have memory protection to stop errors like this (especially if you use a library like dmalloc) and much better debuggers. On the PIC you will just get your program behaving strangely and probably not even in the place that is causing the error. I once allocated an array 1 element too short and didn't notice. Then program started crashing when i added more code, regardless of what the code was or where i added it.

Ferric chloride

Here's me showing my ignorance again, but how do i send a specific modulation wheel event with MIOS Studio? I can move the wheel, but don't seem to be able to just click a button to send a specific number.

My core module seems to be working via MIDI, i uploaded revision_id and it reported correctly that i had a 18F452. However the LCD doesn't work. The first LCD i tried was one that i broke one of the tracks off while desoldering its previous connector and then tried to repair it. I bought a second hand one to replace that but it only displays black bars, so i don't know if it works or if i've damaged the output lines. I'd like to use the LCD Interconnection test, but i don't know how to send Modulation Wheel events. I don't have a keyboard with one and i only have Linux and Free-DOS on my computers so i can't use MIDI-0x. Does anyone have some MIDI files of Modulation Wheel events or a Linux program to send them? I'd create them myself, but then i wouldn't know if i'd written them wrong or my board really was broken.

Nautilus, the file manager for GNOME, has a spatial interface like Mac OS 9. Depending on the distribution you try, it may not be the default as many people didn't like it (probably raised on Windows). Ubuntu and Fedora are the two most popular Linux distributions that use the GNOME desktop.

Find a broken drive/motherboard with it on and unsolder it from there?

That depends on the voltage it uses to do the measurements. Some use a very low voltage so as not to turn on diodes or transistors. Which would give a incorrect reading in this case. You'd be better to put 5V on the DIN and measure the current the input draws. A more expensive, but safer solution is to use a Zener diode to control the voltage. It would look something like this: ^ | 15V | | | -+- | | | | Resistor to limit current | | -+- | | ----- \ / Diode v ----- | +---- to DIN input | /---/ ^ 5.1V Zener /___\ | | ----- --- - Any sort of diode will do, it's just to stop current flowing through the Zener in the reverse direction, you may not need it. The resistor should be (15-5.1)/I, where I is the typical input current for the DIN inputs.

And considering how fast i'm building my MIDIbox FM, it is likely to be a problem of 2008. :) So there's no longer any 8 bit ports that don't have some pins used for special functions?

Off topic, but will the PIC18F4685 work with MIDIbox FM since it uses the same ports as the LCD to talk to the OPL3 module?

The second hand computer stores. They're bound to be getting people trading in PCs with ISA sound cards on them. They may not be keeping them though.

They might do, you'd have to ask. It may be time to resort to eBay or similar. Check the wiki page to see which cards are known to have the OPL3 chips.

I had a look for a datasheet for a YAC516, but i can't seem to find one online. The Yamaha DACs are specific to the synth chip, so anything other than a YAC512 would need a circuit redesign at least. Have you tried your local second hand computer stores?

I'm attempting to design a new control surface for the MIDIbox FM i'm building. I've got a PalmPilot and 6 encoders and i'll probably add some duo-led/buttons. I'm not sure how the existing control surface is used, so i not sure which parts of it i should keep. From the videos of the MIDIbox Seq and MIDIbox SID in 303 mode, it seems important to have as many buttons as possible for quick access to the paramters. But is the MIDIbox FM used "realtime" so much? Should i just concentrate on just making a good "offline" editor for setting up the patches and then not touching it while playing a keyboard? What i'm really asking is, how do people use their MIDIbox FMs?

So far i can tell you that the sysex file you posted contains 26 sysex messages. The smallest is 341 bytes, which writes an program named "Tazer Bass" to id 207. That's all i can get from staring at a hex dump, i'll have to write a 7 to 8 bit unpacker and take a closer look at the .h files next.

Anything is fine. If you know what it does, even better, as you will know if i've decoded it properly. :)

If you're really stuck, you can always try to run it from the command line. Open up a command prompt window, change to the directory of the jar file and run java -jar "MIOS 7_4 beta.jar" That should at least give you an error message if there is something wrong with the jar file.

The .h files describe the data structures and the manual has the encoding of 8 bit bytes to MIDI sysex, so in theory that's all you need. But i don't know enough to about the synth to make a sysex message from scratch. Do you by chance have any hex dumps of sysex messages? Perhaps from a PC based editor? If i had one to decode it should give me a better understanding of how it all works.

That zip file does appear to be include files for ThinkC on a 68k Macintosh. It doesn't have quite enough information. The README says: Do you have a manual that says at least something about the sysex protocol? This is a just set of data structures and it's hard to work out how that corresponds to the data sent over MIDI.

You are allowed to redistribute the runtime with programs written in Java. The licence says: So if you agree not to sue Sun or me, i can email you a bundle of MIOS Studio and the JRE. PM me with your email address and OS/Processor.

Do you know what part of the circuit it's in? If in the main power supply lines, it could be some sort of filter or regulator. If it's in the control lines, it might be a clock generator or transistor. I'm grasping at straws here though, it could be anything. I've seen a LM317 used as a high wattage resistor.

I think so too.

Happy Birthday TK. May you have many, many more.