HELP! Arton IK-51 [Russian synth]: Need rom & schematics

CYBERYOGI =CO=Windler · Guest

I am collector of music keyboards and bought on eBay a defective Arton IK-51, which seems to have a faulty ROM, because it crashes after few seconds.

The Arton IK-51

The Arton IK-51 was made in 1992 as the first Russian music keyboard with digital sound generation and full MIDI support. The concept was like a normal digital keyboard with automatic accompaniment, number selectable preset sounds & rhythms. The percussion is made from medium resolution samples and the main voice uses some kind of wavetable synthesis. On my specimen some main voice timbres of the demo sound like phone dial tones. (Is this normal or a defect?)

Here is some info about the instrument:
www.ruskeys.net/eng/base/arton51.php

what's inside:

The hardware is an incredible masterpiece of handcrafted laboratory grade electronics. It is built like a tank and can be best compared with Tektronix tube oscilloscopes. The heavy aluminium case contains beside some smaller ones 3 huge PCBs, each in the size of a big PC mainboard full of DIL ICs (many with ceramic packages, looking like very early 1980th technology). The external power supply weights as much as an entire modern plastic keyboard; it has a big, console shaped metal case (shaped like one half of the Arton ME-01 guitar processor from 1981) with 2 rubber foot switches {solo, synchro} to control keyboard function. (This is not sustain and hold like a piano. The right one starts rhythm.) The instrument consumes 91VA of electricity (roughly 91W), the power supply itself hums a lot and draws already 16VA with keyboard disconnected. In my IK-51 the 6 EPROMs had no light protection stickers (I immidiately added black adhesive tape) and one IC (KP580BB51A, 9102|28 pin DIL) has 2 strange oval openings; I also covered them with that tape to avoid corrosion. Many ICs turn unpleasantly hot and would deserve a heatsink.

what is faulty:

Unfortunately my Arton IK-51 is faulty and makes a lot of nonsense. When I power it one, the piano keys work only for a few seconds and then fail in semi-random order; trilling a small group of keys keeps this group working until I press other keys. Usually after some additional seconds the entire control panel locks up and does nothing anymore until I power it off and on again. However when I press certain button combinations it will not lock up. E.g. when I type "55", the LED display shows segment mess and most buttons keep working. I can now start the classical demo tune (press right foot switch and a chord section key?), which plays recognizable, but with minor disturbing tones in it. When I press piano keys, the melody gets messed up more, and when I select any accompaniment, everything turns completely into mess. Also the vibrato button turns the main voice rather into a rastered digital siren effect. Most keyboard note pitches are wrong or have different timbres. When I activate the midi button during demo (which turns off the sound generation by piano keys, green LED lit), the demo song plays almost perfectly without disturbing tones, and also the control panel works better. But strange is that the demo tune plays percussion samples related to its notes (i.e. each pitch corresponds to a different drum) and when I select different preset sounds (which works), the set of note related percussion instruments changes also. (Playing keyboard notes does not trigger drums.)

The demo tune can run for a long time without crashing, and also selecting different preset sounds etc. will not lock it up, however when I press "midi" again (unlights green LED) and play keyboard notes, the user interface (keys and buttons) will finally lock up again. Even in locked up state, the demo or rhythm or note mess that the instrument is playing will not stop, and the tempo slider still works. It only refuses to respond on any key or button press, but the sound generation keeps running and also the tempo LED keeps flashing when it was flashing before (which is not always the case even when there is a rhythm audible).

Thus I conclude that the address space is somehow messed up badly, which makes the notes of the demo song trigger percussion, and played keyboard notes somehow throw a wrench into the user interface program. When powered on, the display shows "00111100"(?), which seems to be one of the conditions those make the control panel lock up, because after pressing "stop"(?) during demo, the display shows the same and also here it locks up after few seconds. Possibly only the leading 2 digits "00" cause the crash. When the display shows segment garbage (e.g. during demo), it usually won't crash immediately. Even when there is garbage, selecting functions with the corresponding buttons (rhythm, bass, chord, orchestra) still turns the corresponding display digits into the entered cipher without changing the contents (ciphers or garbage) of other digits.

Due to the missing EPROM stickers I assume that daylight exposure during production of the instrument weakened the bits in a way that it prematurely lost its data. But also the PROMs (not EPROMs) run quite hot, which may have damaged them. (Are these PROMs? I expect that by their handwritten marks.)

They have the following handwritten marks (from left to right):

EPROMs:
DS4="0-46"
DS5="46-01"
DS6="46-02"
DS7="46-03"
DS4="46-05"
DS3="46-04"

PROMs:
DS5 ="045"
DS4 ="044-00"
DS1(?)="044-01"
DS2(?)="be5106045-01"
DS2 ="045-03"
DS1 ="045-02"

The PROM "045" seems to run somewhat hotter than the others, which may indicate a fault.

I need ROM dump & schematics:

This is my keyboard collectors site:
Weltenschule.de/TableHooters/index.html

Please help me to revive this technological dinosaur. The Arton IK-51 is an incredible piece of finest Russian engineer work, that does not deserve to end as scrap like so many other electronic relics those were considered outdated and soon replaced by cheap throwaway mass products.

The EPROMs and PROMs in the Arton IK-51 are:

EPROM: "KC573P[(|)]4A, 9201, Vpr=12.58, 205" (28 pin DIL)
PROM: "P556PT7A, K, [triangle]9102" (24 pin DIL)

o What are the western equivalent types of these ICs? (pinout)

Long ago I bought on a fleamarket a used EPROM burner for Commodore C64 (never used yet - a delicate looking bare PCB card with much accesories) and would like to re-burn the ROMs of the IK-51 with it or at least examine their contents.
o I need the intact ROM dump files for the Arton IK-51 and schematics. Please upload them to your site or e-mail them to me.

-CO-Windler SPAM web.de

o Why has the IC "KP580BB51A" 2 openings? Are they for cooling, or was the IC calibrated or programmed through them during production?

o Why are there many unused connectors and an unused jack outlet in the IK-51?

Was it intended to be upgradeable or compatible with special Russian computers? Is the digital electronics based on any Russian or DDR (German Democratic Republic) standard computer hardware? Was there a programmable synthesizer upgrade planned? Has the hardware similarity with the Vermona SK-86 keyboard?