Sound Blaster AWE32 & 64 Options

The AWE32 came in many varieties, starting with the CT2760, but there are several basic cards which a vintage computer enthusiast should consider.  In this post, I will discuss the various features that separate the usual cards from each other.

Soundfont RAM

All AWE32s come with 512KB RAM, but the AWE32 Value cards omit the SIMM sockets for upgrading the RAM.  Sound Blaster 32s do not have any onboard RAM, but have SIMM sockets to upgrade RAM.  

All these boards can support 28MB RAM, and if the SIMM sockets are used, the onboard RAM is disab+
led.  Use 30-pin SIMMs, 80ns or faster, with identical memory sizes of 1MB, 4MB or 16MB.  You need to populate both sockets.  The SIMM sockets on these boards are usually very cheap and the retaining tabs can break easily.  Epoxy is your friend, but if you wish a less permanent solution, you can try a strong tie.  

The AWE64 came only in two major ISA varieties, with the principal difference being the amount of RAM supported. The Value, CT4380, CT4500 & CT4520,  version came with 512KB RAM and you need to solder a 2-pin header for SPDIF output on all these cards.  The AWE64 Gold, CT4390 & CT4540, came with 4MB RAM.  To upgrade the RAM, you had to purchase expensive, proprietary Creative daughterboards.  People used to use AWESIMM to adapt SIMMs, but today people can use SIMMCON, found here : http://simmconn.tripod.com/.  Only one 72-pin SIMM is required.

Models without RAM upgradeability : CT3780, CT3910, CT3630

Waveblaster Header

If you want to use a MIDI daughterboard like the Waveblaster, Waveblaster II, Roland SCB-7 or SCB-55 or Yamaha DB50XG or DB60XG on your sound card, stay away from the AWE32 Value, SB32 or AWE64, as they do not support the header.

Models supported : CT2760, CT3900, CT3980, CT3990

SPDIF

Virtually all these cards had a 2-pin SPDIF header, even the budget models but on some of the cheaper models you will need to solder pins or wires.  The non-Gold AWE64s are cards where you have to do this.

SPDIF outputs the EMU8000 output.  This includes the FM if using a CT-1747 or CT-1978 chip but not a discrete YMF-262 or 289 chip.  MIDI audio output (from Waveblaster) and CD Audio sound would not be output through SPDIF on any models.  16-bit digitized Sound Blaster audio will also be output on the AWE64 Gold cards, but this functionality may only work in Windows 95 or better.  The non-Gold AWE64 cards almost always have a pair of through holes which you could add a 2-pin SPDIF header.

Note that the AWE32 outputs a 5v TTL digital signal.  This is the same signal that CD-ROM drives with a digital audio output header send out.  They even use the same 2-pin header.  The O is the output pin, the I is the ground pin.  Not all SPDIF inputs will accept this signal.  Fortunately the CD Digital input header on a Sound Blaster Live! or Audigy will.  Moreover, you can connect the pins to an optical/TOSLINK port output, which is accepted by lots of devices.  Coaxial SPDIF is designed for 0.5v to -0.5v peak-to-peak signals.  This is what the Sound Blaster AWE64 Gold provides.

AWE32 Models supported : CT2760, CT3900, CT3980, CT3990

SB32 Models supported : CT3600, CT3620

AWE64 Models supported : CT4390, CT4540

ISA Plug 'N Play

The early AWE32s did not conform the ISA Plug 'N Play standard.  They used jumpers to set the I/O addresses (IOS0 and IOS1), to enable/disable the joystick interface (JYEN), and to select the MPU-401 MIDI I/O (MSEL).  However, IRQ and low and high DMA selection was handled by software initialization via SBCONFIG.EXE or DIAGNOSE.EXE, which reads the settings from the SET BLASTER line in your AUTOEXEC.BAT.

Later AWE32s, SB32s and AWE64s conform to the ISA Plug 'N Play standard and are initialized through the software Creative Technology Configuration Manager (CTCM.EXE) and configured and disabled through the Creative Technology Configuration Utility (CTCU.EXE) or in PNP operating system like Windows 95.  This allows you to disable the joystick, the MPU-401 MIDI interface, the Adlib Ports, High DMA or the whole card.  Unfortunately, if you have to load CTCM, it adds noticeably to the boot time when booting to DOS.

All cards have a jumper marked MFBEN.  This jumper enables or disables NMI generation for the AWEUTIL.COM utility.  This functionality is required when AWEUTIL is emulating a MIDI interpreter in DOS.    If you are not using AWEUTIL other than for initialization, you can remove the jumper.

Models without PNP : CT2760, CT3900, CT3780, CT3910

True Yamaha OPL3 FM Synthesis

Non PNP models have a CT-1747 bus interface chip which integrates a licensed Yamaha OPL3 core.  They sound true to the AdLib and earlier Sound Blasters, but people have individual preferences of which card they like.

All the PNP models of the AWE32 and SB32 have the option to use Creative Quadrature Modulaton (CQM) Synthesis or Yamaha FM Synthesis.  On boards using CQM, there will be a CT-1978 chip.  CQM is generally not objectionable to the untrained ear, but it often sounds harsher and more metallic but slightly crisper compared to a Yamaha FM chip.  Most boards have a silkscreen for a Yamaha YMF-278 and its DAC (very small chips).  Finding boards with the CQM chips are much more common.  However, if you find a board with the Yamaha chip, note that you will not be able to run the chip through the EMU-8000 effects processor.

AWEUTIL is used on the AWE cards to initialize the FM Synthesis output and can be used to apply reverb and chorus effects on the CT-1747 cards through the EMU-8000 chip.  I am uncertain whether cards with a discrete YMF-278 can do that, and the AWE32 Upgrade cards probably cannot as well.

Models using CT-1747 : CT2760, CT3900, CT3980, CT3780, CT3910

Models supporting YMF-278 option : CT3990, CT3600, CT3930

CD Interfaces

Most of these cards come with one, two or three headers for the cable to a CD-ROM.  In the early days, proprietary, incompatible standards came from Panasonic, Sony and Mitsumi.  Some sound cards support SCSI instead, although no Creative AWE cards are known to have done so.  Later AWE cards support an IDE port.  If the card is a non-PNP, the IDE, Sony or Mitsumi interfaces can be disabled.  The Mitsumi interface is a real hardware hog as it uses an IRQ and DMA.  Fortunately the Mitsumi interface can usually be disabled.  The Panasonic interface does not use any resources outside the standard Sound Blaster I/O 2x0-2xF, so it is harmless.

Models with Panasonic/Sony/Mitsumi Interfaces : CT2760, CT3780

Models with Panasonic Interface : CT3900

Models IDE Interface (Non-PNP) : CT3900, CT3910

I assume that the IDE interface on PNP cards can be disabled using the CTCU utility, but I have no experience with such cards.  It may be necessary to disable the IDE interface to avoid conflicts with IDE ports on the motherboard or I/O cards.  Also it should remove any IRQ resource hogging.

On the non-PNP cards with an IDE port, the port can be set to the secondary address, 170-177, tertiary address, 1E8-1EF, or quaternary address, 168-16F or disabled.  The primary IDE address is 1F0-1F7.

Hanging Notes MIDI

It is important to identify games which produce hanging  notes as a result of incompatibility with the various DSP versions of the 16-bit Sound Blaster series. : DOOM, DOOM II, Heretic, Hexen, Raptor, Hocus Pocus, Duke Nukem 3D and Blood are all examples of games which suffer from this bug.  There are other games which may occasionally produce hanging notes regardless of the midi interface being used.  Any game using LucasArts iMuse system may be subject to it.  This includes Star Wars - X-Wing and Tie Fighter (floppy versions) are good examples of such a game.  Only the former are addressed here.  

AWE64s use DSP 4.16, so there will be no hanging notes midi bug.  AWEs prior to that use DSP 4.13 for the most part, and all these DSPs are known to suffer from the hanging notes midi bug.  The bug will only occur when digital sounds and midi are being played.  The best fix for the problem is to use another card for MIDI.  The CT2760 is the card where you will most likely see the 4.11 and 4.12 DSPs.  Rev. 3 of the CT2760 probably has the 4.13 DSP.  This bug will not be present in any card using the CT-1747 chip.  

QSound ASP/CSP

The original AWE32 had, as standard, the CT-1748 QSound Advanced Signal Processor (ASP), later known as the Creative Signal Processor (CSP)., which was an optional upgrade in the Sound Blaster 16s.  All full-length AWE32s should have one soldered onto the PCB.  The AWE32 Value has a socket for a CT-1748 chip, which could have been purchased from Creative Labs.  The SB32s and AWE64s do not have any support for the chip.

All boards with the chip or socket, even if they are otherwise PNP, will have two jumpers to enable or disable the chip.

Models with CT-1748 : CT2760, CT3900, CT3980, CT3990

Models with CT-1748 Socket : CT3780, CT3910

Odd Ducks

The CT3980 is a PNP card, but has a CT-1747 Bus Interface and OPL chip.  It is an exception to the almost universal rule that a CT-1747 chip on-board means that the board is not a PNP board.  In this instance, another chip is used to provide the PNP functionality, but the CT-1747 is certainly used for OPL FM.  

The CT3930 SB32 is a true exception to many of the above categories because it uses the CT2501 ViBRA 16 bus interface chip.  As a result, this board has a discrete YMF-262 OPL3, which none of the other boards have.  This ViBRA chip lacks controls for treble, bass and gain in the hardware mixer.  Finally, there is no PNP or software selectable resource settings, the jumper layout of the original Sound Blaster 16s is used.  In other words, you have to set jumpers to set the IRQs and DMAs.  While the other main SB32, the CT3600, uses a ViBRA CT-2502 chip, those features were put back in the mixer and PNP functionality was enabled.  

CT3630 SB32 and CT4330 AWE32 have no Soundfont RAM.  The CT4330 is really a cut down AWE64.  The CT3670 is a SB32 with SIMMs, but its main chip comes from an AWE64.


The AWE64 Gold has gold plated mini-jack and RCA connectors, RCA jacks not having been used since the Game Blaster.  Some sites claim that it possesses a 20-bit high quality DAC, but that is not quite correct.  The SPDIF connector outputs the full 20-bits of the the standard.  Additionally, it adds the digital PCM audio output to the signal.  Whether the existing 16-bit signals are upconverted to 20-bit or extra bits are just tacked on is unknown.  

There seems to be two main versions of the AWE64 Value, the CT4500 and CT4520.  The CT4520 does not have separate mixer, CODEC or 558 timer chips.  The CT4500 has these, just like all the other AWE cards.  It appears that Creative had integrated these functions into the large QFP chip on the CT4520, whether any functionality was lost is unknown.  

AWE Upgrade

The CT192x requires its own section.  This card was designed as an add-on card for Sound Blaster 16 owners to add most of the AWE features to the PC.  It is sometimes known as the Goldfinch board.  It contains the EMU8000 chip, 512KB RAM, SIMM slots.  It requires its own drivers.  Instead of AWEUTIL.COM, it uses AWEUTIL.EXE.  Game compatibility with AWE32 supporting games may be uncertain as a result.  This board was intended mainly for OEMs like Dell and Micron.

Most CT192x boards only have an 8-pin strip to output audio.  A cable would output audio to the a special header on an OEM motherboard or some (OEM) Sound Blaster 16s.  Instructions and drivers can be found here : http://queststudios.com/smf/index.php/topic,2747.0.html.  CT-192x boards have been reported with Line Out and SPDIF Out jacks.  Usually there are solder points for at least the Line Out.  Some boards may have the 512KB RAM.

Unlike a regular AWE32, you cannot run FM effects through the EMU8000 or output FM through the SPDIF.

Why get an AWE32? : http://queststudios.com/smf/index.php/topic,3477.0.html

Which one should I get?

Since I find PNP cards to be more trouble than they are worth, I would stick with the non PNP AWE32s.  The best of the bunch, feature wise, would be the CT3980, then the CT3900 and CT2760.  However, since the CT3980 is a PNP card, I would pick the CT3900 or CT2760 first.  The CT2760 uses the older CT1701 CODEC chip while the CT3900 uses the newer CT1703 CODEC chip.  The later CODEC chip has been said to have a cleaner output compared with the older CODEC.  I can see people using the IDE port in a system for a CD-ROM drive, but the Panasonic and other interfaces are the very definition of appendices today.  The cards tend to get less noisy as they get newer.  

Sound Blaster 32s are surprisingly good buys, and as they were found in many OEM systems, they tend to be more common than AWE32s.  However, they are truly a great option if you can find a rare one with a YMF chip.