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CYBERYOGI =CO=Windler last won the day on December 23 2016

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About CYBERYOGI =CO=Windler

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    I collect small and strange music keyboards and partly build synths from them. I detailed research 1980th Casio home keyboard hardware.

    My keyboard site WarrantyVoid: http://Weltenschule.de/TableHooters/index.html
  1. Help casio MZ2000 diskkette's

    I have installed 1.44MB diskette drives inside my Amiga (very redesigned Amiga 500 in wooden desktop case), which hardware can generally only handle 720K diskettes (due to low clock rate, but formatted at 880K). When I insert 1.44MB diskettes, it generally fails to read or format them, unless I put adhesive film over the upper left corner hole of the diskette to make the drive treat it as 720K. Likely parameters like bias current or simply the data rate to an internal buffer differs in both modes, so a 720K mainboard (Amiga 500) with 1.44MB diskette drive fails to read or write 1.44MB diskettes because drive and mainboard are in different modes. Can an intact Casio MZ2000 read 1.44MB diskettes at all? If not, it is likely the same situation than in Amiga.
  2. Casio Rap-1 Rapman repair?

    If keys show a systematic fault (e.g. every 8th key does not work), then one of the keyboard matrix lines may have been interrupted (e.g. broken foil cable or a corroded PCB trace by battery leak acid or a bad solder joint). The bad connection needs to be found and resoldered.
  3. Casio CDP-100 Loud Notes Stutter

    I am no expert in CDP-100, but the symptome looks like a power supply issue (or dead batteries). The instrument will keep resetting (likely also changes preset sound and rhythm to default if it has that) by voltage drop during loud notes played through its internal amplifier because this draws higher current. Do you have connected it to a too weak (less mA than rated on the instrument, e.g. 300mA instead of 1A) non-original AC-adapter? Also a broken AC-adapter (e.g. bad capacitors) may cause this.
  4. Casio HT-6000

    Check the headphone jack. There is a switch contact inside that disconnects the speaker when headphone is plugged in. If there is a bad solder joint at its input (by mechanical stress), neither that speaker nor headphone side will work. Also a badly oxidized contact inside the jack can make the speaker fail (happens often in 6.3mm jacks of 1980th Bontempi/Farfisa keyboards), although typically the headphone would work on both channels.
  5. CT 460 stuck key

    The plastic hook that keeps the key down has obviously cracked off (happens easily when a keyboard got carried roughly by lifting at the keys). If you can find the plastic fragment inside the instrument, reglue it with superglue. Else you may try to make a hook of sufficiently firm wire (e.g. stiff (non-wick) copper cable) and hotglue it to the key bottom.
  6. The G1 - Second Time Around

    I suspect that the hardware reason why Casio made no combined XW-P1/G1 model is that they reused a special CPU they had created already in 1990th, which sounds good by highly optimized handmade machine code (so they can't easily replace it), but supports a too small address space to access enough ROM (actually flash memory) to handle the features of both instruments at once. Of course they could have used bank switching, but there may have been a deadline for quickly finishing the chip or such stuff. That is to say, compared with average modern single chip hardware (e.g. Raspberry Pi) the system is surprisingly tiny, which can not be explained with RAM/ROM price anymore, but only by the oldfashioned virtue of "programming on the metal". An in depth technical analysis can be found in this thread: Pooched XW-P1
  7. Problems with XW-G1 Firmware Updater 1.10

    Are Casio XW-G1 now dying during firmware updates too? This absolutely sucks. :-( The main problem is an atrocious design flaw that completely erases the internal flash memory (including bootloader) before downloading the update into RAM from PC. Thus switching the instrument or power off after starting firmware update is absolutely deadly to the operating system and makes the mainboard unbootable. I.e. once firmware update has begun, *never ever* disconnect power to the Casio keyboard (no matter if your laptop crashes or windows reboots or you need to rent or buy a new laptop in between because yours refuses to finish that pesky procedure) before new firmware has successfully loaded into the instrument. An in depth technical analysis can be found in this thread: Pooched XW-P1 That bricked mainboard disease could have been easily avoided by not overwriting the flash boot loader during update. In computer engineering study I learned that building a system design like this is almost a sacrilege. But other companies built such trash too; e.g. plenty of Samsung laptops died of an UEFI bug by attempt of installing Linux. The XW-P1 and XW-G1 mainboards even seem to be identical (other than software), so I hope that hardware hackers will eventually learn how to refurbish those boards using an eprommer to rewrite the flash memory chips on them with the original firmware.
  8. CT-403 Repair

    I see, the Casiotone 403 is one of the faux woodgrain models, which has an internal power supply and is mechanically different. It is likely mechanically similar like my Casiotone 401 (even same accompaniment chip). The 401 is quite heavy (about 10kg?) because despite its case looks almost perfectly like wood, it is mainly made of plastic coated sheet steel. (Casiotone 201 and 202 were of genuine wood.) In spite of this it is not as robust as it appears, because at the corners of the side pieces (made of pressboard?) the plastic woodgrain tends to peel off. I had to hotglue mine back into place, but this sheet plastic stuff also cracks off easily when accidentally folded to hard. The high quality speaker sits in an own thick plastic compartment of that even the cable hole was sealed with glue to turn it into a perfectly closed box. It is driven by a large hybrid amplifier module that is screwed to a sheet metal heatsink welded to the case bottom. This makes it very unpleasant to remove the mainboard because you have to unscrew the module and mess around with (possibly poisonous) old heat conductive paste. The front panel is held by screws (those in the 403 seem to be at the sides). I don't know how yours is built, but (if like 401) be careful with the 5 metal lashes with screw holes those hold the rear part of the control panel from inside. With case opened, these lashes are sharp as razor blades and easily damage the panel and PCB traces; with mine a preset sound LED failed by an accidentally cut trace after working on the opened keyboard. After soldering the trace I glued ribbon adhesive tape over the sheet metal lashes to make them less dangerous. After opening, a lot of broken small black rubber rings fell out of the case - likely they belonged under the piano keys somewhere for damping (keys feel a little loose), but turned brittle by oily room air or ozone. I don't have a service manual of my 401, but got a photocopy of Casiotone 403, which was of great help to understand the general hardware architecture, because it has the same accompaniment hardware combined with the main voice section of Casio MT-60 (first 403 models had CPU version D776G with external bugfix circuitry). They are a good didactic example how Casio in early instruments made several different CPUs cooperate and combine their keyboard matrices rather than the centralized master-slave approach found in later hardware, and how despite almost self-contained CPUs often minor functions like clock rate conversion or preventing wrong key press order during preset sound selection used a crazy amount of "glue logics" ICs cluttering up the mainboard.
  9. CT-403 Repair

    This can be everything. May be a crack in the PCB (torn traces) or a switch or jack has ripped out of it. If a special chip cracked, it can not be repaired, but likely parts need to be soldered back in. If it fell on a plugged in plug, contacts inside a (e.g. power supply) jack may be bent and thus prevent it from turning on.
  10. Would this constitute abuse of a Casio?

    By specification, many potentiometers survive less than 1000 motion cycles - in real life much more, but the fate of DJ console crossfaders (and some lousy slide pots in old Bontempis) prove that they breakdown by constant use. It is not abuse unless a Casio is smashed and burned on stage or such demolition show crap. But why this mechanical solution if you have a microcontroller!? This is not a Hammond Novachord (1st full polyphonic tube synth, with freakish complicated mechanical timbre switch mechs). You may simply simulate a variable resistor e.g. by an optoisolator (photo transistor + LED, or LDR + incan if you want smooth (but slow) transition) or simply controlling the input through an 4066 analogue switch IC and feed it with a current produced by the Arduino. Very likely the pitchbend potentiometer is polled like a homecomputer paddle port, i.e. a charged capacitor is polled by a digital input that counts the time until voltage drops below a threshold. (The duration is used as the detune value.) Then a current recharges the cap and everything repeats. You may easily simulate that by testing for the recharge pulse and then pull the voltage down (or up, depends on circuit) for an adjustable time through a resistor to simulate the potentiometer position. To keep the pitchbender functional, you may also wire your input parallel with the pot through a resistor. Voltage values may need to be tweaked (possibly through an op-amp, but likely a trimmer is enough).
  11. Next Casio Product Wish List

    I seriously doubt that a 2500$ synth (which may be sold in quantities of some 100 to maximum few 1000) would be considered by Casio worth to start a production run. Casio tends to make rather several 100000 copies of their plastic products than deciding to go that low. (Exception was the "Symphonytron 8000" modular stage organ system, of those only 100 were made - likely because it sold so badly.) I doubt they will add 8GB samples anywhere in their hardware. E.g. the XW-G1 contains only 32MB flash memory and 512KB RAM, operated by a COB (black blob) CPU that likely runs on something like 48MHz. I suspect that they perfected that special CPU in 1990th (thus it has limited address space) and only slightly improve it among keyboard generations. They have learned to write a nicely complex and versatile synth engine software (may be in highly optimized assembly language) on it, but can not easily port that to modern hardware and so keep making inexpensive instruments with low memory and strange limitations. in this thread is my brief analysis: Pooched XW-P1 Casio better should keep making their normal instruments and iron out technical flaws those deter professionals (like missing midi-sync in XW-PD1). Also offering e.g. their Privia hardware to furniture companies to built digital grand pianos (those don't sell in large enough quantities to be shipped by Casio from Japan) would make sense, because reasonably cheap piano-shaped objects by noname companies revealed to contain toy grade hardware (like those silicone rollup pianos) those weren't good for anything than room decoration. Casio is not that low-end as some snobbish musicians claim; nowadays Chinese no-name tablehooters often were much more horrible than Casio home instruments. (With Yongmei-like trash e.g. polyphonic play failed by omitted matrix diodes, flimsy plastic resembled yoghurt cups and tiny switching power supply PCB on flimsy wires looked like designed to set the room on fire once the brittle single screw plastic post falls off.) Casio should focus on making a new equivalent of the VL-1, i.e. inexpensive hardware with editable sound parameter. I would love to see e.g. a remake of the classic SA-series (SA-20 etc.) with LCD display, USB and a fully editable version of its unique "PCM" (first softsynth on a chip) sound engine, made for about 50 to 100€. It should be useable with or without computer and be capable to store sequencer data and sound patches on USB stick or SD card.
  12. Casio RZ-1 Drum Machine

    Snares and cymbals in classic drum machines with low sample rate are (unlike other drums) often output unfiltered, i.e. the samples will not sound dull, but the overtones you hear are fake (stair steps of the waveform). I haven't checked if this is done in RZ-1 (service manual can be found online). The same percussion IC however is also used in Casio CZ-230S. This is what I wrote about it. The percussion generator "NEC D934G" (64 pin SMD, pins count anticlockwise) is a percussion sound IC with external sample memory, that was used in some Casio keyboards from mid of 1980th and (2 of them) in the RZ-1 drum computer. Percussion samples can be in ROM or in RAM for a sampler function, but sampling has to be done by the controlling CPU (e.g. " NEC 7811G-120" in RZ-1). The samples seem to be only 8 bit, but can be magnified by 2 additional volume control bits (pin DB6, DB7) from the CPU for accents. Percussion sound is output at 20 kHz through an external 10 bit DAC. Its analogue waveform then has to be routed through 4 sample & hold circuits to separate the 4 multiplexed analogue percussion channels (synched by the 80 kHz CLOCK output). The D934G can output 2 percussion sounds on each channel (named 'alpha' and 'beta'), those apparently can be separated further by 2 trigger signals from the CPU. The CZ-230S uses more pins than RZ-1 - likely due to larger address space.
  13. 8 Keys Not Working

    A faulty key group (or every n-th key is dead) is often a bad solder joint in the keyboard matrix. However if factory reset fixed this, then it is likely a software-related problem, which may be caused by power surges, static electricity, EMP (lightnings) or accidental unplugging while powered on. battery problem? Does the XW-G1 store user data in SRAM or flash memory? While the latter may make it prone to firmware corruption if implemented unsafely (i.e. no write protected address space), SRAM will freak out when battery runs empty. This may be even a soldered tiny rechargeable lithium button cell hidden on mainboard, that drains over time (possibly many months) when main batteries are not inserted or empty. E.g. my much older Yamaha MK-100 makes bugs those can be absurdly confusing if you don't know what's going on. That is to say, the MK-100 stores all settings in battery backed up RAM; with no batteries inserted the RAM is backed up by a large electrolytic capacitor for a few days(?). When the cap runs empty, this messes up the data badly and even causes things to subtly malfunction those normally were expected not to be RAM dependant. E.g. sometimes particular preset sounds plays too silent or certain parts of them refuse to be editable, or their LEDs show mess or sustain doesn't work or even the chord volume slide switch refuses to change volume at some positions (e.g. only 2 of the 5 positions have different volume). These flaws can drive you crazy and make you take the entire thing apart for hours to successlessly search for dirty switches etc. etc. and even in the manual I downloaded from Yamaha there is no reset procedure for this keyboard explained to prevent this. (In manuals of later Yamaha PortaSounds with battery backed up RAM stands usually that certain simultaneous button presses reset the thing.)
  14. Pooched XW-P1

    It is a bit strange that the modern XW keyboards have so little memory. My Casio MT-540 of 1987 had 768KB (mask) rom, which was quite a lot upon that time. (For comparison, the entire RAM of an Amiga 500 homecomputer of the same year was only 512KB and its rom 256KB.) The SRAM IC9 "R1LV0414DSB" on the XW mainboard photo is only 512KB (organized 256kWord*16bit) and thus way too small to hold the complete firmware during update. But if the hardware or firmware (by what reason ever) can only execute "chip erase" to format the entire ROM (i.e. nothing left to boot from), it for sure still would have been possible to load the boot code (flash loader) from PC into SRAM before starting erasure and then immediately write this part back into flash rom without depending on a still properly working PC program and USB connection. This way the keyboard would never become unbootable after power-off (unless a freak accident or extreme stupidity causes a power fail or powers-off just between formatting and reinstalling the boot loader) and could still always boot into the flash loader, no matter what happens to the PC or connection. Has anybody tried to load the BIN files from the update program on a small SD card (old hardware often supports maximum 2GB) or even USB stick and tried to start the keyboard firmware update mode with it inserted? If the CPU contains mask rom (it very likely does), it would be plausible to include such a fallback method if the normal method went wrong. It may be that special file names or other strange tricks are needed to make it work (possibly another button combination or even connecting 2 special pins on the mainboard), but before discarding the mainboard I would try to boot directly from SD or USB media. (What is the procedure with Privia or older Casios with updateable firmware? Is there something similar?) E.g. the CTK-2080 service manual mentions an easteregg, namely holding buttons "0"+"1"+"2" together during power-on enters a diagnostic program (aka test mode or service mode) where various functions can be checked. Items are selected with the cipher buttons. Button "9" displays rom version and model number. 0 = return to main menu 1 = button check (press all keys and buttons in a certain order) 2 = LCD check 3 = AC adaptor check 9 = rom version check If USB works correctly, it will show in Windows device manager an item "USB Audio Devices" under "Sound, Video and Game Controllers". Power off to exit. (But I guess this works only with intact firmware and not when it is already bricked.)
  15. Pooched XW-P1

    The flash updater apparently first erases the entire firmware and so the only thing that keeps it capable to communicate through USB lives in RAM, i.e. power-off is deadly. The fact that the CPU has a software number (at least in CTK-2080) suggests that there is a mask rom built-in. But that it can not communicate by itself with the updater is a massive design flaw. Isn't there a way to save firmware (possibly those 2 .BIN files) on an SD card and press a button combination to make it boot from there? On the rear edge of the XW mainboard I saw (on photo) an unused 9 pin connector "CN9". May it be that this is used in factory to load firmware first time, or do they really need to flash the roms before soldering them in? The IC1 and IC11 have marks of 2 blue or 3 yellow dots, those may get added after successful flashing. But the handwritten model number on PCB back and the empty "MX-[______]" and "[NO._____] fields looks like when the mainboards are generic (made for several models) and only receive their firmware when they are actually installed (or sold as an expensive spare part). The flash ROM type "MXIC MX29GL128ETL2I-90G" can be found in the datasheet of "MX29GL128E" (56 pin TSOP) by Macronix. It has "128Mb x8/x16" architecture, i.e. it contains 128Mbit that can be accessed as bytes or 16bit words. (I.e. the instrument has 32 megabyte rom in total, which is not much in an age where you can buy several GB flash memory per Euro or US$. Nowadays it would be cheaply possible to put several CDs full of hifi samples into such an instrument, which makes me suspect that possibly the employed special CPU is too old to address more memory. It might even be that this was the technical reason to make a separate XW-P1 and G1 with each different omitted features, although I guess this was rather a marketing decision, because bank switching through external small parts is nothing new.) The MX29GL128E chip contains various security stuff including a "Solid Protection Mode" and a "Password Protection Mode". (These are likely functions needed for SD-cards.) It is unknown if the XW hardware makes use of them. Also individual sectors can be write protected. There is a "chip erase" command to auto-erase (format) itself without need of complex software interaction, which may be what the updater does.