When I opened the 2168, I found a Pro Audio Spectrum 16 (PAS16) manufactured and released by MediaVision in 1992. Dosday.co.uk has a fantastic three parts review of it.
Overall, it is a capable card. However I heard cracking during audio playback. Only 122 titles supported the PAS16. The standard of the time was Creative's Sound Blaster which required MediaVision users to load an annoying compatibility driver AUDBLAST.DRV (which didn't always work).
There was also the case of missing documentation. Besides an obscure p16q&a.txt, I couldn't find much about the card. Not knowing how to control the IRQ and I/O bugged me greatly.
Most importantly, that was not the card I always wanted and could never afford. After defeating AdLib with the Sound Blaster 1, Creative kept on innovating at an impressive pace with the Sound Blaster Pro which added stereo capability. In April 1992, they solved audio for PC with the Sound Blaster 16 able to play CD quality (16-bit, 44Khz, stereo) samples.
Back then I was only able to afford a second hand Sound Blaster Pro. So I set on finding a Sound Blaster 16 with a DSP (called ASP).
I ended up landing a version CT1740 (which is also well reviewed on dosday.co.uk).
The box is satisfyingly huge with a LOTs of goodies. There is even a microphone in it. Fun fact: If you plug it in the card output, you can hear sound coming out of it!
Notice the year 1992 all over the chips. This card was born one year prior my 2168.
Notice the CT1741 DSP chip is soldered. Cheaper version of the SB16 came with an empty socket allowing purchase of the ASP only if needed.
On the list of I/O we find the Panasonic connector for CD-ROM in the back end of the card. On the backplate, there is a thumbwheel volume control, a DA-15 port, a line in jack, a mic in jack, and an out jack.
Back in the days I only ever thought of the DA-15 as the Game port[1]. To me it was only meant to welcome a joystick and play flight simulators. Little did I know that it could also be used as an output to send MIDI commands to a MPU 401-UART!
The recurring theme of this project is that nothing ever worked on the first try. That is exactly what happened after I inserted the SB16 in the chassis. The reason why my PC was mute is because there was an IRQ 5 conflict between the Sound card and the Network card. It was interesting to see how my memory had selectively erased the joy of IRQ conflicts resolution.
| Card | IRQ | DMA | I/O |
|---|---|---|---|
| Ether16 Network | 5 | - | 240 |
| Sound Blaster 16 ASP | 5 | 1,5 | 220h, 330h |
I did not want to change the default of the SB16 because games are easier to set up if everything remains default. I decided to change the IRQ of the Ether16 (which is only used by mTCP) instead. I was comforted in my decision to make an effort and produce parts with the manual and the drivers (instead of having to chase for documentation that would kinda be what I have).
As a primarily Windows 95 PnP card, the Ether16 does not have adjustable jumpers. To change the setting, one must start Ether16's SETUP.EXE and rewrite the cards' EEPROM.
The whole thing took 5 minutes. It was barely an inconvenience.
After that, I had a conflict free system, able to access the network and play songs!
| Card | IRQ | DMA | I/O |
|---|---|---|---|
| Ether16 Network | 3 | - | 240 |
| Sound Blaster 16 ASP | 5 | 1,5 | 220h, 330h |
There is no way for the software to automatically detect what base address and I/O are set on the sound card. These must be human entered via a configuration program (e.g.: SETUP.EXE) or via env variables (e.g.: The legendary BLASTETR=A220 I5 H5 P330 T6).
I am going to bring up again how satisfied I was to have the manuals. The Getting Started explains every register and every jumper. There is even a drawing naming the chips and their location on the card.
My favorite SoundBlaster tool is SB16MIX.EXE which is a TSR able to overlay the DOS prompt. Everything can be configured from there. It obviously doesn't work in games.
| ^ | [1] | Wikipedia: Game port |
