Yamaha PCS-30

squarewave keyboard with Playcard slot & key lighting

This instrument from 1984 was Yamaha's smallest key lighting keyboard with Playcard System (see Yamaha PC-100). Unlike PC-100, the sound generator here is simple squarewave and resembles MC-3.

The PCS-30 has officially only each 6 OBS preset sounds and rhythms, but by a Playcard trick you can select some more. There is also a simple single finger accompaniment. Beside less features, the behaviour and sound of this instrument is almost identical with the newer Yamaha PSS-160, thus I only describe here the differences.

different main features:

32 midsize keys
6 OBS preset sounds {violin, organ, clarinet, piano, guitar, vibes} (selected through slide switch)
6 OBS preset rhythms {march, disco, 16 beat, rhumba, swing, waltz} (selected through slide switch)
rhythm volume slide switch (6 steps including mute)
analogue tempo slider
Playcard System key lighting (30 red & yellow LEDs above the keys, tape card slot)
no variation & fill-in buttons
no sequencer
no demo button
complex multi-chip hardware:

CPU= "Toshiba TMPZ84C00P, 8438ABS, Japan" (= Zilog Z80?, 40 pin DIL)
sound IC= "Yamaha YM2142, 4Y 20 87 C" (24 pin DIL)
matrix decoder?= "Yamaha YM3514, 4Z 04 54 E" (64 pin zigzag DIL)
ROM= "Yamaha YM2211-22712, 4X 08 86 C" (28 pin DIL)
RAM= "8443, HM6116P-4, 00004550, Japan" (24 pin DIL)

It contains plenty of ICs for such a small thing, including a standard Z80 CPU?

This is the tape head.

eastereggs:

additional preset sounds & rhythms selectable: Set orchestra/ rhythm slider into intermediate position, start a Playcard song that employs any additional sound or rhythm and press "stop". The current sound and rhythm of that song now stays selected for normal play until a different sound/ rhythm is selected.
likely all features of the Yamaha PSS-160 addable through key matrix eastereggs.

notes:

The behaviour and sound of this instrument is almost identical with Yamaha PSS-160. The only difference seems to be the analogue tempo slider, the lack of battery alarm and many omitted buttons. Also the "orchestra" slide switch here does not retrigger held notes but only mutes them when slid to decaying sounds. The "guitar" sound corresponds to "harpsichord" on PSS-160. The rightmost key lighting LED is abused as power and tempo LED during normal operation. After power-on sometimes random LEDs light up. Then they fall dark and a light quickly walks from the leftmost to that rightmost LED and stays there. The instrument makes no sound until this about 3 seconds long boot sequence has finished.

In spite of the many similarities with the PSS-160, the hardware of the PCS-30 is far more complex and employs a separate RAM and ROM IC; the ICs have even function names printed on the PCB. The main CPU is marked "Z80"; so far it is really an ordinary Z80 CPU, it would make it easier to reverse- engineer and emulate the PlayCard data format. The keyboard has a sheet metal frame like known from other old Yamahas. (I haven't examined the hardware closer yet.)

My specimen from eBay fortunately came with a big stack of additional Playcards from multiple different looking sets (see here), those also work with my other Playcard System keyboards. Some cards show an "arpeggio" slider setting, but unlike Yamaha PC-100, the PCS-30 has neither arpeggio nor this slider.

A 44 midsize keys variant of the PCS-30 was released as Yamaha PC-50 (same case style in white with transposer knob). But possibly it belongs to another hardware class, because the preset sounds {organ, violin, clarinet, piano, harpsichord, vibraphone} and rhythms {march, waltz, slow rock, jazz rock, swing, rhumba} are named differently.

*removal of these screws voids warranty...*

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