I did enjoy that. Good info dump for future searchers 👍

This is interesting!

I've been using Media Vision Thunder Boards (SB 1.5 clone) in my Tandy TL builds. The Thunder Board is hardwired to DMA 1. Haven't run into issues previously, though I never tried Outrun. I'll have to give that a try and see if it has issues.

Shponglefan wrote on 2023-07-31, 03:46:

This is interesting!

I've been using Media Vision Thunder Boards (SB 1.5 clone) in my Tandy TL builds. The Thunder Board is hardwired to DMA 1. Haven't run into issues previously, though I never tried Outrun. I'll have to give that a try and see if it has issues.

It basically was freezing my system anytime I tried to use the Tandy DAC at all. That includes music and sound programs on Deskmate as well. Every time I tried to play something, the system would freeze. Now it works!

I wonder if your Media Vision card already has DMA Sharing enabled and is already on IRQ5 to avoid conflicts with the Tandy DAC. Also, the TL might be slightly different with the DAC. Not sure, but definitely let me know if Outrun freezes your system or if it works along with the DAC sound effects.

Pierre32 wrote on 2023-07-31, 03:35:

I did enjoy that. Good info dump for future searchers 👍

Thanks! Glad you enjoyed it!

The "DMA Sharing" jumper on the SB2.0 and Pro cards never did anything helpful for me in this regard; I've long-since been using software-configurable cards in Tandy PSSJ-bearing systems instead. Since the sharing sounds like it's working for you, I'm curious to know what the difference might be. What "DSP" version does your SB2.0 have?

Presumably, you still need to do a hard power-cycle when switching between use of the SB2.0 and Tandy DAC, or no?

Cloudschatze wrote on 2023-07-31, 04:07:

The "DMA Sharing" jumper on the SB2.0 and Pro cards never did anything helpful for me in this regard; I've long-since been using software-configurable cards in Tandy PSSJ-bearing systems instead. Since the sharing sounds like it's working for you, I'm curious to know what the difference might be. What "DSP" version does your SB2.0 have?

Presumably, you still need to do a hard power-cycle when switching between use of the SB2.0 and Tandy DAC, or no?

I thought I was going to have to get a software configurable card, but I was surprised that this actually worked. According to the markings on the chip, I have DSP Version CT1336A '92 (which I assume stands for 1992), and again, the card is a CT1350B.

Also surprisingly, I can switch back and forth between Tandy DAC and SB 2.0 without any resetting or power cycling of any kind. There is a mod tracker I use that has support for both Tandy DAC and Sound Blaster, and I can switch back and forth inside the program, and they both work without a hitch. Of course, I haven't found any programs that try using them at the same time, but I would assume that would freeze the system.

It's crazy because I went from the system freezing every time I used the Tandy DAC to both devices working perfectly, and all I changed was the DMA Sharing Jumper.

jnnelson79 wrote on 2023-07-31, 04:15:

According to the markings on the chip, I have DSP Version CT1336A '92 (which I assume stands for 1992), and again, the card is a CT1350B.

CT1336A is the newer version of the bus interface chip, and is likely paired with a 2.02 DSP/MCU. That combination could be the difference.

Also surprisingly, I can switch back and forth between Tandy DAC and SB 2.0 without any resetting or power cycling of any kind.

That's desirable behavior right there. 😀

Even with software-configurable cards like the SB16, the behavior I experience is that, once DMA channel 1 is configured for use by the card, it becomes unavailable to the Tandy DAC until either the system is rebooted (and with the card left in an "unconfigured" state), or until the SB16 is soft-reconfigured to use a different DMA channel instead. The latter method works well on-the-fly.

Cloudschatze wrote on 2023-07-31, 06:01:

jnnelson79 wrote on 2023-07-31, 04:15:

According to the markings on the chip, I have DSP Version CT1336A '92 (which I assume stands for 1992), and again, the card is a CT1350B.

CT1336A is the newer version of the bus interface chip, and is likely paired with a 2.02 DSP/MCU. That combination could be the difference.

Hi, that reminds me of the early days of the CMS GAL reverse-engineering..
Didn't the early code require a specific version of the CT1350B, as well?
I vaguely remember that with the wrong revision, the OPL2 part could be fried. Or so we worried at the time.
Anyway, it just came to mind. I thought that in both cases the interface chip could be at fault.

jnnelson79 wrote on 2023-07-31, 03:53:

Not sure, but definitely let me know if Outrun freezes your system or if it works along with the DAC sound effects.

Just tried Outrun in my Tandy TL and it didn't work. Choosing the CGA option causes a system reboot, while choosing the Tandy option causes it to lock up.

I even tried removing various expansion cards including the video card, Thunder Board and MIDI card, and it still didn't work.

Shponglefan wrote on 2023-08-01, 23:07:

jnnelson79 wrote on 2023-07-31, 03:53:

Not sure, but definitely let me know if Outrun freezes your system or if it works along with the DAC sound effects.

Just tried Outrun in my Tandy TL and it didn't work. Choosing the CGA option causes a system reboot, while choosing the Tandy option causes it to lock up.

I even tried removing various expansion cards including the video card, Thunder Board and MIDI card, and it still didn't work.

Sorry to hear that! It always worked for me with no issues when I had no sound card installed. The TL should be very similar to the TL/2.

jnnelson79 wrote on 2023-08-02, 02:45:

Shponglefan wrote on 2023-08-01, 23:07:

jnnelson79 wrote on 2023-07-31, 03:53:

Not sure, but definitely let me know if Outrun freezes your system or if it works along with the DAC sound effects.

Just tried Outrun in my Tandy TL and it didn't work. Choosing the CGA option causes a system reboot, while choosing the Tandy option causes it to lock up.

I even tried removing various expansion cards including the video card, Thunder Board and MIDI card, and it still didn't work.

Sorry to hear that! It always worked for me with no issues when I had no sound card installed. The TL should be very similar to the TL/2.

Just set up my Tandy TL/2 and tested Outrun again. With the Thunder Board installed I tested it five times with several different outcomes:

1) 2 out of the 5 times it worked perfectly, all digital sound effects seemed fine and no lock-ups.
2) 2 out of the 5 times times I was able to launch the game and the initial digital voice played properly. But the game itself locked up when starting a race.
3) 1 out of 5 times, it completely froze on a black screen and the digital voice did not play.

So that's 2 out of 5 attempts it seemed to work fine with the Thunder Board.

Shponglefan wrote on 2023-08-14, 02:13:

Just set up my Tandy TL/2 and tested Outrun again. With the Thunder Board installed I tested it five times with several differe […]
Show full quote

jnnelson79 wrote on 2023-08-02, 02:45:

Shponglefan wrote on 2023-08-01, 23:07:

Just tried Outrun in my Tandy TL and it didn't work. Choosing the CGA option causes a system reboot, while choosing the Tandy option causes it to lock up.

I even tried removing various expansion cards including the video card, Thunder Board and MIDI card, and it still didn't work.

Sorry to hear that! It always worked for me with no issues when I had no sound card installed. The TL should be very similar to the TL/2.

Just set up my Tandy TL/2 and tested Outrun again. With the Thunder Board installed I tested it five times with several different outcomes:

1) 2 out of the 5 times it worked perfectly, all digital sound effects seemed fine and no lock-ups.
2) 2 out of the 5 times times I was able to launch the game and the initial digital voice played properly. But the game itself locked up when starting a race.
3) 1 out of 5 times, it completely froze on a black screen and the digital voice did not play.

So that's 2 out of 5 attempts it seemed to work fine with the Thunder Board.

That’s really interesting! I wonder why it’s so inconsistent? Did you try each time from a fresh boot? It works every time on my TL/2, but of course, I don’t have a Thunder Board.

jnnelson79 wrote on 2023-08-14, 02:23:

Shponglefan wrote on 2023-08-14, 02:13:

Just set up my Tandy TL/2 and tested Outrun again. With the Thunder Board installed I tested it five times with several differe […]
Show full quote

jnnelson79 wrote on 2023-08-02, 02:45:

Sorry to hear that! It always worked for me with no issues when I had no sound card installed. The TL should be very similar to the TL/2.

Just set up my Tandy TL/2 and tested Outrun again. With the Thunder Board installed I tested it five times with several different outcomes:

1) 2 out of the 5 times it worked perfectly, all digital sound effects seemed fine and no lock-ups.
2) 2 out of the 5 times times I was able to launch the game and the initial digital voice played properly. But the game itself locked up when starting a race.
3) 1 out of 5 times, it completely froze on a black screen and the digital voice did not play.

So that's 2 out of 5 attempts it seemed to work fine with the Thunder Board.

That’s really interesting! I wonder why it’s so inconsistent? Did you try each time from a fresh boot? It works every time on my TL/2, but of course, I don’t have a Thunder Board.

Each attempt was after a hard reset (reset button). Not sure why it's inconsistent though I imagine it might be due to DMA issues? It's unfortunate the Thunder Board lacks any DMA options; it's permanently set to DMA channel 1.

Unfortunately I don't at the moment have an SB 2.0 to compare with, though I do have a couple other SB clones. I may test those to see how they perform.

Any idea if an ESS Audio Magician Plus has DMA sharing? The only unknown jumper is JP5, and it's either with or without a jumper (only two pins).

This card allows the user to select a DMA (I've never seen DACK and DRQ labels before, but some internet searching says this is DMA settings and they both have only two options: 1 or 3), and despite changing it to use DMA3 (if that's what setting both of those jumpers to 3 does), it still cannot use its DAC. The computer freezes any time a program tries to use the sound card DAC (but the Tandy DAC works fine).

I cannot find any info about this specific card. The info I found is not explicitly specific to this card, via looking up the chipset (ES488-F, which got me the only search result with only a mostly-similar card, but not the actual one I have), and FCC ID: HUBESSAMP26. I found no info at all for the other identifier string: P058-01-001-10.