While the Sound Blaster, with its joystick/midi port and digital sound processor began to sell well, the design was definitely in the past with lots of TTL logic chips. The card was originally marketed as a "stereo" card, but the only thing stereo about it was the Game Blaster chips. In the first production runs, the two Game Blaster chips, marked with a CMS-301 sticker were soldered onto the motherboard (so were the Ad Lib chips, marked FM1312 and FM1314). However, almost nobody really cared about Game Blaster when the Adlib was also present, and virtually all games that supported the Game Blaster also supported the Adlib, so for the 1.5 version of the Sound Blaster, the chips were not installed by default. The two empty sockets could be populated with chips purchased from Creative Labs fr the low, low price of $29.95.
After CL released its new flagship product, the Sound Blaster Pro, it redesigned the original Sound Blaster as a budget card and released it in late 1991. CL enhanced the new card's capabilities by allowing it to record up to 44.1kHz, but it was still a mono card. The C/MS chips were left off the board again, but this time there was a third empty socket. A special version of the upgrade was required from CL, one not really well-identified in the catalog accompanying the card. The third chip had a sticker marking it as 0048013500, and underneath it was a pre-programmed PAL (Programmable Array Logic) chip. (A PAL16L8 chip with the security fuse blown so it could not be dumped). Eventually, CL stopped advertising the upgrade completely, and without the PAL chip the CMS functionality would not work even with the Phillips chips were installed. Given the rarity of boards with the upgrade found in the wild and the lack of advertising, few upgrade kits must have been sold.
However, in 2012, a long-time member of the Vintage Computer Forum named Chuck(G) devised a method to determine the way in which common PALs were programmed. He analyzed the PAL on an officially upgraded Sound Blaster 2.0 and released the instructions to replicate the programmed logic on a GAL (Generic Array Logic) chip. Unlike PALs, GALs can be reprogrammed and do not require expensive and hard to obtain hardware to program. The GAL required is a GAL16V8 and the file to program the chip can be found here : http://www.vintage-computer.com/vcforum/entry.php?328-Cloning-a-HAL-PAL-Part-11. The programmed chip is inserted in the only empty socket that can fit it, the one just above the FM1312 /YM-3812 chip. However, in almost one year following the first successful report of a GAL SB 2.0 CMS upgrade, not all boards have worked with the upgrade. Below I try to identify each board known whether or not to work with the upgrade.
Board Types :
The earliest known boards are CT-1350B boards marked with a rev 2, 3 or 4 and do not have "SOUND BLASTER" silkscreened. Here is a photo of a rev. 3 board :
And here is a rev. 4 board :
Between the rev 2 and 3 and the rev 4 and later boards, there is one obvious difference. The rev 4 added a DMACTL jumper. This jumper will disable the DMA capabilities of the Sound Blaster, virtually eliminating its ability to reproduce digitized sound. However, and it may not be truly visible in the photo, but both share a CT1336 Bus Interface Chip and a CT1351 DSP chip, version v2.01. You can identify the DSP chip by this silkscreened text on the chip "CT1351V201", with the "V201" indicating the version number.
These boards have been proven time and time again to work with the CMS upgrade, whether a GAL or PAL. Apparently there is no difference between Lattice Semiconductor and National Semiconductor GALs. Apparently SGS Thompson GALs do not work.
Later boards look like this :
Now the words "SOUND BLASTER" are next to the CT1350B. This board's revision can be determined by the six digit number silkscreened to the lower left of the address jumpers. The above board is a 049151 and it works with the upgrade. 059316 and 069328 are also known to exist and shown below :
Note the new CT1336A and DSP v2.02 on these boards. The 059316 also has small surface mounted versions of the YM3812 and Y3014 chips and a 1993 copyright date silkscreened onto the board. The last four digits refer to the design date of the revision in year-week format. The 059316 and 069328 are the first boards confirmed not to work with the CMS upgrade, regardless of whether a CL PAL or a modern-programmed GAL is used. However, the 049151 is not guaranteed to work, as can be seen here :
It seems that the first two digits, 04, 05 or 06, refer to a revision number. There are some mysteries remaining. For example, will either one of these boards work :
The first is a 049151 with a v2.02DSP and a CT1336 chip, the second one is identical except for the word "SOUND MACHINE".
After further testing, it has been determined that that the DSP version does not matter, the CT1336 version does. If your card has a v2.01 DSP or v2.02 DSP, the upgrade will work. If your card has a CT1336 Bus Interface Chip, the upgrade will work. On the other hand, if your card has a CT1336A Bus Interface Chip, the upgrade will not work! Since v2.02 DSPs tend to be paired with CT1336A chips, be very careful to check the bus interface chip before you buy. Make sure your seller shows you a photo of the exact card you will receive.