Moonsound is the name of a sound card released for the MSX home-computer system at the Tilburg Computer Fair in 1995. It was designed by electronic engineer Henrik Gilvad and produced by Sunrise Swiss on a semi-hobby basis. It arrived after the US branch of Microsoft abandoned the MSX system, instead focusing on the IBM PC. The name originates from the Moonblaster software that was written for people to use the hardware plug-in synthesizer. Overview Based on the Yamaha YMF278 (OPL4) sound chip, it is capable of 18 channels of FM synthesis as well as 24 channels of 12 and 16 bit sample-based synthesis. A 2 MB instrument ROM containing multisampled instruments was unusual for its time. From the factory it came equipped with one 128 KB SRAM chip for user samples. History Two generations were made. The first is a small size PCB without a box. Later, a larger size PCB which fit into an MSX cartridge was available. The later version had room for two sample SRAM chips resulting in 1 MB of compressed user samples. Sound effects Sound effects like chorus, delay and reverb are omitted due to cost, size and usability reasons. The Yamaha effect chip requires its own specialised memory and effect routing is basic. All 18 FM channels and 24 channels of sample-based sound shares the same effect setting. Creative step-time sequencer programmers made pseudo effects like chorus, reverb and delay by overdubbing or using dedicated channels to repeat notes with delay and stereo panning. This is effective but quickly reduces the musical complexity possible. Specifications Moonsound version 1.0 had one socket for user sample RAM. Moonsound version 1.1 and 1.2 had two sockets for up to 1 MB SRAM. Some hackers and modders found out how to stack two additional SRAM chips resulting in 2 MB of SRAM. Being based on the OPL4 chip, The FM registers of Moonsound are compatible with the OPL, OPL2 and OPL3 chips. The MSX-AUDIO contains a chip which is similar to and also compatible with the OPL. Therefore, some older software can make use of the Moonsound. The 2 MB ROM contained 330 mono samples, mostly at 22.05 kHz at 12 bits, but with some drums at 44.1 kHz. The FM part of the OPL4 chip can be configured in several ways: 18 two-operator FM channels 6 four-operator FM channels + 6 two-operator FM channels 15 two-operator