Crystal CS-4248

The CS-4248 was one of Crystal's first audio codecs for PC sound cards, introduced in 1993.

	Released	Late 1993
	Bus	ISA 16-bit
	FM Synth	None
	Sample Range	4 - 50 kHz
	Packages	68-pin PLCC (-KL) or 100-pin TQFP (-KQ)
	Standards	None
	Plug & Play	No
	See Also	CS-4231

CS4248 is an Mwave^TM audio codec from Cirrus Logic/Crystal, designed to take multiple analogue audio inputs, convert them into a digital signal, apply filtering and then convert them back into a combined/mixed analogue audio signal.

Mwave^TM MDSP1020 and MDSP2780 was a line of DSP chips created by IBM in joint partnership with Texas Instruments in late 1993/early 1994. It was not only designed for gaming audio, but also for voice/fax/modem use, so don't be surprised if a sound card with an Mwave chip also includes an onboard modem.

Apparently Mwave^TM DSPs do support FM synthesis compatible with Ad Lib and Sound Blaster, though I have yet to confirm this. There's a possibility the MDSP1020 was a sound chipset of which the MDSP2780 is the wavetable-only part - in this assumption, the MDSP1020 has a separate chip to provide FM synthesis.

The Mwave DSP was integrated into IBM's ThinkPad 755-series and IBM PC 300 desktop series.

The CS4248 can be found on:

• Terratec Maestro 16 - with Yamaha YMF262 + CompuMedia chip
• Terratec Profimedia 16/96 - with Yamaha YMF262 + CompuMedia chip
• Aztech Sound Galaxy NX Pro 16 - with Yamaha YMF262 + other Aztech chips
• Aztech Washington 16 - with Yamaha YMF262 + AZT2316. Also sometimes CS4231 instead of CS4248
• Shuttle HOT-223 (Spacewalker Sound System 48) - with OPTi MAD16 chip

Revisions

Competition

 

In the Media

 

Setting it Up

Crystal wrote their own device drivers for the CS-4231 / CS-4248. These were available for Windows 3.1 and Windows NT 3.5x.

Downloads

Datasheet Nov 1993

Driver Datasheet Nov 1993

 

More Pictures

IBM Mwave Dolphin audio/modem card (1993)