There's a complete list of synth engines used by Casio?

[silent]

12 hours ago, Just Alex said:

Is firmware for that keyboard downloadable?

 

IDK, you might have to see if there is a firmware repair disk somewhere around or something... or read BlkSend data from it via midi...

[CYBERYOGI =CO=Windler]

According to the service manual block diagram, the MZ-2000 uses mask roms (and SRAM to hold user data), so I doubt there were firmware update diskettes available. I remember reports that sometimes in this model the synth behaviour got corrupted in strange ways; I don't know if this is indeed rom bitrot (they may be disguised proms) or just mess in the sram which certainly can be cleared by disconnecting the CR2354 lithium battery. So the faults may be symptoms of empty battery.

[silent]

On 2/18/2023 at 6:01 PM, CYBERYOGI =CO=Windler said:

According to the service manual block diagram, the MZ-2000 uses mask roms (and SRAM to hold user data), so I doubt there were firmware update diskettes available. I remember reports that sometimes in this model the synth behaviour got corrupted in strange ways; I don't know if this is indeed rom bitrot (they may be disguised proms) or just mess in the sram which certainly can be cleared by disconnecting the CR2354 lithium battery. So the faults may be symptoms of empty battery.

Casio uses LSI CMOS Chips in their keyboards, so it could also be corruption of the synth engine itself...

Also, the WK-1800 does have firmware, when you are in diagnostic mode you can see the version, and I think it lets you load new versions to the keyboard via a few methods...

Also the WK-1800 has a more powerful CPU than its siblings.

 

edit: they would have been firmware repair discs or programs, or both. Not update discs, unless a new one was released. Although it is possible that expansion discs came with firmware when bought from the official source.

Edited February 20, 2023 by IrreverentHippie
Adding Details

[CYBERYOGI =CO=Windler]

If it had mask roms, the repair shop likely would have needed to order a physical set of new rom chips from Casio instead of burning eproms. The MZ-2000 rom chips already were SMD (PCB layout in service manual) and thus less easy to handle with an eprommer.

Edited February 21, 2023 by CYBERYOGI =CO=Windler

[silent]

1 hour ago, CYBERYOGI =CO=Windler said:

If it had mask roms, the repair shop likely would have needed to order a physical set of new rom chips from Casio instead of burning eproms. The MZ-2000 rom chips already were SMD (PCB layout in service manual) and thus less easy to handle with an eprommer.

Possibly... Although it could have been possible to load new versions or repairs for the system firmware from disc.

[CYBERYOGI =CO=Windler]

This is impossible. ROMs can not be rewritten, only desoldered and replaced by a new physical chip to install a new version.

[silent]

What about the secondary memory chip on the WK-1800 used to store the user presets and expansion disc data?

1 hour ago, CYBERYOGI =CO=Windler said:

This is impossible. ROMs can not be rewritten, only desoldered and replaced by a new physical chip to install a new version.

How would something like that work? since you can clear it and put the data back in however you want to...

[Revenant]

The user memory on the WK-1800 is just battery-backed RAM. It's totally separate from the actual firmware, which uses pre-programmed mask ROM inside the microcontroller.

 

Check out the service manual: https://www.manualslib.com/manual/2572980/Casio-Wk-1800.html

LSI9 is the Hitachi MCU with built-in ROM, LSI7 and LSI8 are the RAM for user stuff, LSI3 is the sound chip, and LSI1 and LSI2 are the wave ROMs.

[silent]

20 hours ago, Revenant said:

The user memory on the WK-1800 is just battery-backed RAM. It's totally separate from the actual firmware, which uses pre-programmed mask ROM inside the microcontroller.

 

Check out the service manual: https://www.manualslib.com/manual/2572980/Casio-Wk-1800.html

LSI9 is the Hitachi MCU with built-in ROM, LSI7 and LSI8 are the RAM for user stuff, LSI3 is the sound chip, and LSI1 and LSI2 are the wave ROMs.

The WK-1600 does not have the secondary DSP attached ROM chip that the WK-1800 does have

What is on that second chip that is important to only the WK-1800?

[silent]

On 5/10/2020 at 3:38 AM, CYBERYOGI =CO=Windler said:

The Casio jargon for sound synthesis engine is "sound source". The different engines have cryptic 2 or 3 letter abbreviations proudly mentioned in ads, but with exception of some professional synthesizers the deeper meaning and inner working was hidden from customers (not even told in service manuals). So many of these may be rather advertisement buzzwords than technologies, enshrouding that they were just minor variations of older sound engines. This list is likely inaccurate, because many old or low grade sound sources were not mentioned anywhere, so I only added them from own hardware examination. Also with modern models (large compressed samples) and pianos I am no expert. The IXA sound source (CTK-1000 from 1993) was the last engine with many classic synthesized sounds (now even with velocity and some editable parameters), although it already lacks the famous (SA-series) program loop synthesis preset sounds with complex algorithmic envelopes. After IXA Casio dropped the use of synthesized preset sounds in favour for long wavetable samples imitating natural instruments, which IMO makes newer keyboards mostly boring. With the HPSS sound source from 2013 (XW-G1 synth) fortunately a new versatile synth engine came out, which however does not fully include older (e.g. PD) synth algorithms. This list is sorted by technology rather than release date.

(I can not enter this as HTML table here, so it is a little messy.)


List of Casio sound sources:

sound source full name 1st use notes & features year

plain squarewave
? ML-80 monophonic squarewave (1:1, 100% tremolo) 1979
? ML-81 monophonic squarewave (1:1) with decay envelope 1980
multipulse squarewave
? VL-1 monophonic multipulse squarewave with switchable fixed filter. 1981
? PT-20 like VL-1 with obligato + chord/bass voice. 1982
? MT-11 2 layered bipolar multipulse squarewaves with switchable fixed filter. 1983(?)
? MT-200 bipolar multipulse squarewave with switchable fixed filter. 1984(?)
stairwave
CV Consonant-Vowel synthesis CT-201 2 mixed stairwaves with switchable fixed filter. CT-201 & 202 layer 2 such sound CPUs with each a filter. 1980
? VL-5 only 1 stairwave with switchable fixed filter (very different hardware). 1982(?)
? MT-65 programmable CV (sound IC with external CPU). 1983
? CT-6000 velocity sensitive CV variant (layering 3 sound ICs). 1984
SD Spectrum-Dynamics synthesis HT-series user programmable CV variant with VCF for synthesizers. 1987
additive synthesis
? 1000p additive synthesis (5 layered sinewaves, sounds drawbar-like). 1981
Phase Distortion (FM)
PD Phase Distortion CZ-series Casio's FM synthesis variant. 1984
iPD Interactive Phase Distortion VZ-series PD successor with programmable routing. 1988
speech synth
? TA-1000 data-reduced speech synthesis (LPC based?, PARCOR?) 1983(?)
sampler
? SK-series lofi sampler (SK-1 has also drawbar softsynth). 1986
? FZ-series 16 bit sampling synthesizer. 1987
? SK-60 lofi sampler on different PCM engine hardware. 1996
software based (wavetable + multiple synth algorithms)
PCM Pulse Code Modulation various,
e.g. SA-series Casio wavetable softsynth on a chip, including many other synth algorithms like FM variants or program loop synthesis. The generic term "PCM" was earlier used for anything sample based (e.g. Casio percussion ICs). 1988
CD Casio Digital ? MT-540 PCM engine version with external 16 bit sample ROM. 1988
Super CD ? CT-770(?) PCM engine version with velocity, effect DSP (external 16 bit sample ROM).
AP ? AP-7 PCM engine version with velocity, used in first Celviano piano. 1991
? VA-10 PCM engine version with effect DSP + Harmony Arranger. 1992
IXA Integrated Cross-Sound Architecture CTK-1000 PCM engine version with velocity, multisamples, effect DSP (external 16 bit sample ROM | last engine with many synthesized classic "PCM" sounds). 1993
A2 A² (A-square) wavetable with sample compression + effect DSP.
HL Highly compressed Large waveform A2 successor?
ZPI Zygotech Polynomial Interpolation MZ-2000 IXA successor(?) with special sample morphing. 2000
AHL Acoustic & Highly-compressed Large-waveform CTK-4000 HL successor with acoustic instrument multisamples. 2008
AIF Acoustic & Intelligent Filtering System Privia piano simulation 2009
AiR Acoustic and Intelligent Resonator Privia piano simulation 2013
HPSS Hybrid Processing Sound Source XW-G1 PCM engine successor for versatile synthesizer (partially hardware based). 2013

You are correct on A2 being a wavetable, I think ZPI is also a wavetable, but it has more advanced features like an actual ADSR and wave-morphing.

[silent]

On 11/29/2022 at 6:43 AM, CYBERYOGI =CO=Windler said:

The term "DSP" is relative. Some may use it as a generic term for postprocessing effects within softsynths. Even very poor sounding Bontempi 1980th toy grade lofi keyboards were advertised to have a "digital signal processor".

 

By the way, I found the likely world first single-chip softsynth. It is the "Sound FX Phasor" by the unknown British company Electroplay made in 1980 (1 year before Casio VL-1!) - a soundtoy in the shape of a handheld barcode scanner computer, which foil touchpad has only 16 buttons (15 act as "white" keys, no sharps), and the synthesizer is running on a tiny PIC microcontroller with only 768 byte ROM + 32 byte RAM.

 

Beside 8 preset effect noises it has a keyboard mode with synthesizer, featuring suboscillators with multipulse squarewave and freakish siren-like howling modulations. The monophonic sounds are even more complex than VL-1. Particularly it can do sonorous organ-like bass notes and crunchy motor noises with simple decay envelope and also strange semi-metallic gongs and clangs. The grainy lo-fi sound engine employs program loop synthesis in the style of Williams early electronic pinball machines. But unlike VL-1 it is more centered on less melodic howling effects, and often resembles random glitch stuff with strange techno sound loops those can include crackle, buzz and rough pulsing or bleeping noises, so it can be somewhat compared with POKEY (the famous Atari 8-bit soundchip). But the relation is more like that of Phase Distortion to FM - despite similar principles, the character of the timbres and its parameters can substantially differ and make of it a unique sound source.

 

The Sound FX Phasor was way ahead of its time. This is the same type of British low-cost miracle like the first Sinclair homecomputers. It could have been a game changer; under different circumstances UK instead of Japan would have created the VL-Tone. But the user interface is awful. There is no sequencer, synth patches can not be saved and most obnoxious is that auto-power-off deletes the created patch (up to 31 key presses) after 46 seconds of idle. The single page manual does even try to explain the synth parameters (6 letter buttons, each 0..255?), and the software seems full of bugs those cause semi-random behaviour. Fortunately I managed to dump the rom code and make schematics to reverse-engineer this amazing technical marvel. Likely it can be emulated, and perhaps I will write a better softsynth of the algorithm to turn it into a well playable instrument.

 

The WK-1800 uses a Hitachi Wavetable+Effects chip (HG51B155FD). I am wondering if the chip technically has more voices since the MZ-2000 uses two matching chips with one being for the synth and one being for the effects. The Wavetable on the WK-1800 is still quite advanced and can sound very good if given the chance, tho I wish there was a better instrument editor for it. Also, for some reason its CPU has a DAC and ADC on it. It also for some reason routes the sound data through the key controller and possibly back through the rest of the synth engine? It's very confusing. Also, that synth is LOUD. Powered Speakers are no joke.

Edited February 27 by silent

[silent]

23 hours ago, silent said:

The WK-1800 uses a Hitachi Wavetable+Effects chip (HG51B155FD). I am wondering if the chip technically has more voices since the MZ-2000 uses two matching chips with one being for the synth and one being for the effects. The Wavetable on the WK-1800 is still quite advanced and can sound very good if given the chance, tho I wish there was a better instrument editor for it. Also, for some reason its CPU has a DAC and ADC on it. It also for some reason routes the sound data through the key controller and possibly back through the rest of the synth engine? It's very confusing. Also, that synth is LOUD. Powered Speakers are no joke.

I have NOT been able to find any datasheets on that DSP, but I found one for the CPU and one for DAC. Btw, the DAC has a 18bit mode. Modding perhaps?
Anyway, meow meow!