Casio TSA-90 Sound Maker (alarm clock with SA-series accompaniments)

This rare analogue alarm clock made in Thailand is the likely most bizarre spinoff of the Casio SA-series. It's 24 selectable alarms are exactly the rhythm and accompaniment patterns of SA-35 and even have tempo control.

main features:

eastereggs:

notes:

It is unknown what Casio had planned with this. For an alarm clock the speaker in its deep triangular case sounds surprisingly good, and the selection of sound patterns with tempo control is odd. Possibly they intended to create a cheap beginner's drummachine with accompaniment, but the M6387 CPU turned out to be a poor choice, so they may have stopped the project in the middle and decided to only make an alarm clock of the half-baked thing. The chip internally still supports 5 drumpads with 3 sound sets, but I found no rhythm start/stop button nor pattern variations nor other kinds of programmability.

My version TSA-90J-1 (a Japan import, bough used on eBay) has a yellow clockface and came in an undecorated plain beige original box with blue Casio label. The clock still has the orange sticker "SOUND MAKER 24" with the intended retail price of 5800 Yen; apparently this version was sold only in Asian countries. On eBay I saw another package variant in colourful printed retail box that depicts a blue version with cyan clock face and red speaker. It came with multilingual manual, but the clock itself (also depicted on box side) had colours like mine.

In my Japanese language instruction sheet the 24 patterns have the same names like in SA-35. The 4th step of the volume slider (loudest, like 3) acts as alarm test mode to always activate the sound at full volume as an accompaniment device. If you want to play them quieter, simply remove the clock battery (the AA cell closest to the set knobs) and set the clock hands to alarm time.
 

hardware details

The Casio TSA-90 is based on classic SA-series keyboards. It is built around the "OKI M6387-19" CPU with amp IC "Motorola AN8053N" (16 pin DIL).
The analogue quartz movement has a separate 1.5V AA battery and its alarm contact in series to the alarm off switch simply interrupts the supply voltage to the sound hardware (powered by 4 AA batteries) when alarm is not sounding. The 4th step of the volume slide switch bypasses both to act as alarm test mode.

keyboard matrix

The keyboard matrix has no diodes. Each row is one function. The pattern starts and keeps playing automatically so long the CPU is connected to power. The 'pattern' switch simply changes the matrix row of the 'select' switch to change among {rhythm, accomp, funny}. Technically they don't need to be locking. With all slide switches open (intermediate position), the CPU starts with default pattern '8 beat', tempo 4 and volume 5.

As eastereggs there are 5 drumpad buttons + select button (3 banks). The lots of empty matrix places next to them look wasted, but make sense to avoid collisions by the lack of diodes.
 
11 KI0
12 KI1
13 KI2
14 KI3
15 KI4
16 KI5
17 KI6
18 KI7
 
CPU pin
in 0
in 1
in 2
in 3
in 4
in 5
in 6
in 7
in / out
 
8 beat
16 beat
swing
slow rock
shuffle
march
samba
waltz
out 0
(rhythm)
30 KO0
rock
pops
jazz
funk
house
country
latin
classical
out 1
(accomp)
29 KO1
fanfare
hopper
computer sound
horror
child's play
orient
jungle
comedy
out 2
(funny)
28 KO2
1 (slow)
2
3
4
5
6
7
8 (fast)
out 3
(tempo)
27 KO3
1 (quiet)
2
3
4
5 (loud)
5
5
5
out 4
(volume)
26 KO4
 D. 1
-
-
-
-
-
-
-
out 5
25 KO5
 D. 2
-
-
-
-
-
-
-
out 6
24 KO6
 D. 3
-
-
-
-
-
-
-
out 7
23 KO7
D. 4
-
-
-
-
-
-
-
out 8
22 KO8
D. 5
-
-
-
-
-
-
-
out 9
21 KO9
D. bank
-
-
-
-
-
-
-
out 10
20 KO10

The input lines are active-high, i.e. react on +Vs. Any functions can be triggered by a non- locking switch in series to a diode from one "out" to one "in" pin (which here is not needed).
 

legend:
D.
 = drumpad
orange
background 		 = easteregg
grey 
background		 = unconnected doublet

  • drumpads
    The 5 drumpads connect from pins 25..21 (outputs) each to pin 11 KI0. The bank select button at pin 20->11 cycles through 3 sound sets. By the special layout no diodes are needed.
     
    bank
    drumpad
     
    1
    2
    3
    4
    5
    1
    		 base snare tom (synth-) hihat cymbal
    2
    		 conga afro percussion (hi) agogo (hi) cowbell (lo) clave
    3
    		 car horn laser beam marimba (ringing) wah voice bird (pearl drop)

    These percussions are very close to preset sounds found in Casio SA-1. The 'tom' is a typical synth tom that goes "piu!". The bird tweet seems to be a very short note of 'pearl drop'. The ringing 'marimba' may be intended as a classic phone bell. (Unlike SA-1, ring tempo does not change with volume setting.) Holding drumpads does not change the sound duration, i.e. e.g. marimba was not meant to simulate a bell alarm clock. They also don't stop or interrupt the rhythm/ accompaniment pattern.

The software number 19 of the M6387 CPU seems to be a castrated version of version 16 found in the SA-35. So order and content of the rhythm/accompaniment patterns are fully identical. But by the changed keyboard matrix most other features were omitted to implement the simple slide switch control without diodes. Shitshot experiments (diode in series to 330 Ohm resistor across quartz pins) hint that much of the original program code may be still intact. So despite the matrix seems to support no demo button, it e.g. could glitch into a loop that played "Twinkle Twinkle Little Star" simultaneous with the selected rhythm/accompaniment pattern (still switchable); only tempo control was disabled.

Another analogue alarm clock with SA-series sound is the Casio TSA-85 Space Sonic 8 (one slide switch for 8 sounds), which only plays short looped samples through a simpler CPU.
 

 removal of these screws voids warranty...    
WarrantyVoid
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