Viewing Issue Advanced Details
ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
08010 Sound Trivial Always Jun 17, 2021, 23:30 Jun 18, 2021, 15:43
Tester jkburks View Status Public Platform MAME (Official Binary)
Assigned To Resolution Open OS Windows 10 (64-bit)
Status [?] Acknowledged Driver
Version 0.232 Fixed in Version Build 64-bit
Fixed in Git Commit Github Pull Request #
Summary 08010: rockclim: Missing BGM from Epson Melody IC
Description Taito Rock Climber has unemulated BGM provided by Seiko EPSON 7910C Melody IC
This is confirmed by hardware video and PCB photo (below)
The video also confirms graphics and colors.

This report should be linked to galaxian_rockclim.cpp rather than galaxold.cpp, but the new driver is not available from the list at the time of this report.
Steps To Reproduce
Additional Information The hardware video was posted to twitter:
The media is flagged for "potentially sensitive content" so you must click the view button.

The follow up post includes a photo of the 7910C chip on the PCB. Also click view button.
I have attached the photo to this report so it does not get lost.
User provides link to site with information about the IC with mp3 audio files of the output.

-text translation-
The 7910 series is the first electronic melody IC released by Suwa Seikosha (later Seiko Epson).
An IC that applies the company's low-voltage CMOS technology enables his 1.5V operation with a single dry cell battery.

One or two melody and two alarm sounds can be selected, and two chords (square wave) can be combined and output. It has two independent envelope generators and can play proper music even though it is an early melody IC. In addition, it has an external transistor driver and can drive the speaker.

The one-shot product in the table below is triggered by the playback terminal, and he plays it once. Other than that, playback ends when the sounding when the playback terminal is opened ends.
-end translation-

The first linked track is the music played in Rock Climber. Melody begins after the Yankee Doodle tune at start.

Data Sheet for EPSON 7910 Series Multi-Melody IC
Github Commit
Regression Version
Affected Sets / Systems rockclim
Attached Files
jpg file icon rock_climber_melody_7910C_IC.jpg (247,831 bytes) Jun 17, 2021, 23:30 Uploaded by jkburks
Rock Climber PCB Photo - 7910C Melody IC
There are no relationship linked to this issue.
User avatar
Senior Tester
Jun 18, 2021, 10:09
edited on: Jun 18, 2021, 10:09
as you say, the video seems to confirm the ugly sprite colours as correct at least, which does surprise me. it also seems to have an issue with the bullet circuit as there's always a stray bullet flashing on the screen.

I guess this is one of those 'doorbell ICs' as Phoenix etc. use, so the melody will be inside it, and ideally one will need to be decapped.
User avatar
Senior Tester
Jun 18, 2021, 10:17
I mirrored the video (as unlisted) for future reference