The Sound Blaster 1.0 (code named "Killer Kard"), CT1320A, was released in 1989. In addition to Game Blaster features, it had an 11-voice FM synthesizer using the Yamaha YM3812 chip, also known as OPL2. It provided perfect compatibility with the market leader AdLib sound card, which had gained support in PC games in the preceding year. Creative used the "DSP" acronym to designate the digital audio part of the Sound Blaster. This actually stood for Digital Sound Processor, rather than the more common digital signal processor, and was really a simple micro-controller from the Intel MCS-51 family (supplied by Intel and Matra MHS, among others). It could play back 8-bit monaural sampled sound at up to 23 kHz sampling frequency and record 8-bit at up to 12 kHz. The sole DSP-like features of the circuit were ADPCM decompression and a primitive non-MPU-401 compatible MIDI interface. The ADPCM decompression schemes supported were 2 to 1, 3 to 1 and 4 to 1. The CT1320B variety of the Sound Blaster 1.0 typically has C/MS chips installed in sockets rather than soldered on the PCB, though units do exist with the C/MS chips soldered on.