Just logged on to our webserver and removed the files with a few clicks. Did you ever wish that parts of your history could be rubbed out that easily? Maybe I should post these words wrapped into embarrassment-tags ;-). But as in real life, this plan will not work out, of course. Searching for terms like „web archive“ will bring up http://www.waybackmachine.org/ in example. If you forgot about the how and when of your first website, it will take you willingly back to the old times, no matter if you like it or not.

After almost four years with the old frame-based design, I decided to start something new. Ok, the old site may have been just moderately ugly, but from the technical point of view it was really bad. Moved over the old contents so far, and most of the old links will be valid for the next few days until having informed my dear top-referers. Also you may use http://www.kessener.net/hajo/ to get to the old site. And yes, I will switch to something else than the default template asap ;-).

The Voltcraft Accu-Trainer AT1 is a charging device for AA and AAA NiMH and NiCd cells. It comes with an integrated switching power supply for direct mains connection instead of using a wall wart. The AT1 and it’s relatives AT2, AT3 and AT8 are popular chargers, at least in Germany, with the reputation of treating accus nicely and not frying them.

A few month ago I got this piece at our local Conrad Electronic store in Hannover. They have these plastic boxes located near the cashpoints where you can find faulty or B-stock pieces at reduced prices. This stuff is definitely worth a look as very often you will get properly working units with only a few cosmetic drawbacks. BTW: You know that you got an „out-of-the-plastic-box“ unit if there is a big cross scribed somewhere on the housing with a screwdriver or knife. Keep an eye on it, maybe this is your next eBay snip.

Well, this time it was not cosmetic but a real fault. So I disassembled the AT1 and put it on the desk with a breadboard as isolator and powered up the isolating transformer to go for error search. There was neither smoke nor smell nor any other sign of life, nothing obvious. The switching power supply did not look as if this job would be fun, anyway.

Switched off and checked the semiconductors with ohmmeter and diode tester, checked resistors and capacitors without result. To check the capacitors in-circuit I used a new toy, the Elektor In-Circuit Kondensator-Tester and found one capacitor with ESR value 1Ω to be possibly critical, two others had ESR value 0Ω which is optimal.

Powered it up again and started measuring voltages. This is always a bit fiddly with mains on the board, even behind an isolating transformer. Beneath the controller PIC16C72A there was a three legged something hidden under a shrink hose that looks like a voltage regulator. On supposed input there were 14 volts, on output there was nothing and the output is connected to Vcc of the controller, hmm. Cut the shrink hose to have a look at the labeling.

Found an LM340T5 which is better known as 7805 voltage regulator. This is an easy one; you may be out of toilet paper but you will never miss a 7805 in your spare parts inventory. After replacing I did a quick check using a dead AA accu sticked with tape between the contacts and… yup!

Pulled over a new shrink hose, reassembled the AT1 and that’s it. If you own a dead AT1 maybe this post could be helpful. Although integrated in a very small housing and with internal power supply the device gets hand-hot normally which is a good perspective for long life and reliability.

CeBIT 2005 Hannover, Germany

SyxLoader is a little tool for sending MIDI system exclusive data from SYX Files (.syx) or Standard MIDI Files (.mid) to your MIDI devices.

About SYX files
SYX files are the simplest way to store system exclusive data. They contain raw MIDI data in one or more blocks as transmitted via MIDI when performing a bulk dump. Unlike SMF, no timing information is included. The only thing a parser has to know or assume about a SYX file is that one or more data blocks may occur, each beginning with system exclusive status byte F0h and ending with F7h (end of exclusive, EOX). The contents in between are not of parsers interest but only for the dedicated MIDI device.

About Standard MIDI Files (SMF)
SMF are a common and standardized way to interchange time-stamped MIDI data between computers or MIDI devices. The file format was specified by the MIDI Manufacturers Association (MMA).

Quick Guide
Files can be opened as usual but drag & drop is supported and recommended. Some keyboard shortcuts are provided for basic control. The Save as.. allows you to save (and thus convert) a loaded SYX file to an SMF.

There is an Offline option to close the MIDI output and make it available to other applications without closing SyxLoader. May be useful.

Transmission can be paused and resumed. This is not really an essential option for a sysex tool as most MIDI devices do not like interruptions. It may be useful if you put several dumps with distinct pauses into one file and stop transmission to change the MIDI output.

In between ..
SyxLoader splits big sysex events into parts of 1024 bytes by default. To get this done internally, the subsequent parts are handled as separate events with status byte F7h (EOX). Delta time in ticks between these events is calculated as follows:

Measure warp
With the Save as… option there is one thing to mention about the saved SMF: In case they contain music next to sysex data you will experience a measure warp along the timeline. This is due to SyxLoaders fragmentation algorithm which not only splits big sysex blocks into small ones but also shifts the position of all subsequent events to the amount of calculated delta times; see the animated GIF below. This warping is a feature, not a bug.

Update for Version 1.5 (12. August 2007)
Recently a user contacted me, who was not able to get just one sysex dump out of his Miditech MIDIFACE USB interface without experiencing a sporadic data loss and ridiculous amounts of data bytes wrongly transmitted on the MIDI output. So I ordered a MIDIFACE myself and found it to be one of those USB class-compliant interfaces which do not need a special driver and just work out of the box. They are sometimes called „driverless“, but of course they are not. Instead — under Windows XP — it is the OS’s usbaudio.sys driver which handles them.

It turned out that with usbaudio.sys an application should not pass a big sysex event with more than one call of midiOutLongMsg() unless you want the output data to be severely corrupted. In other words, the driver and probably all thereby driven class-compliant MIDI interfaces will handle sysex data correctly if you avoid the commonly used split output buffering. A typical drawback of usbaudio.sys are blocking calls to midiOutLongMsg() that will not return until the driver has synchronously transmitted all of the passed MIDI data.

SyxLoader now offers a preferences dialog to control the splitting behaviour. With Maximum Blocksize you may either vary the split size or — recommended, if you use a class-compliant device — disable the splitting by choosing ignore (do not split). Please be aware that the progress bar on SyxLoader’s main window may appear „chunky“ or frozen while transferring big non-splitted MIDI dumps.

Download
SyxLoader is built with Borland C++Builder 6 using Theme Manager by Mike Lischke. It is designed to run on Microsoft Windows 2000/XP and comes with Inno Setup installer. Please tell if you find errors or want further features to be added – your feedback is welcome.

SyxLoader is freeware and provided to you as is. It is assumed to work properly but may be erroneous and have malicious effects on your computer systems or MIDI devices. Download and use at your own risk.

Download SyxLoader 1.5 (~607KB)