VOGONS


First post, by almeath

User metadata
Rank Member
Rank
Member

Generally, I find that the Tandy sound emulation in DOSBox is very good, although I have to admit that it has been many many years since I heard the output from a real Tandy PC.

However, in Skate or Die, something has always sounded off, and so I got around to testing the game in PCem (v17) as a point of comparison. I used the default settings for a Tandy 1000. In DOSBox I used machine=tandy and set the cycles to 500.

I have attached the intro music, labelled accordingly. I presume that PCem is producing a much more accurate output. Notice the speed of playback as well, given that I have already set the cycles in DOSBox to quite a low level.

Something is obviously way off on the DOSBox sound emulation. I do not know anything about coding at this level, so this is not a complaint, just an observation. I am not sure why the Tandy sound seems to work so well in other titles, but fails here. Perhaps this is a known issue and is scheduled to be looked at sometime in the future?

Attachments

  • Filename
    Skate_or_Die_Tandy_DOSBox.mp3
    File size
    1.39 MiB
    Downloads
    14 downloads
    File comment
    Skate or Die (intro), Tandy 1000 (DOSBox SVN)
    File license
    Fair use/fair dealing exception
  • Filename
    Skate_or_Die_Tandy_PCem.mp3
    File size
    2.97 MiB
    Downloads
    14 downloads
    File comment
    Skate or Die (intro), Tandy 1000 (PCem)
    File license
    Fair use/fair dealing exception

Reply 1 of 6, by ripsaw8080

User metadata
Rank DOSBox Author
Rank
DOSBox Author

Hmm, the faster DOSBox "interpretation" doesn't necessarily sound bad, though... I think I might even prefer it. 😉

I notice some debug log message about strange things going on with IRQ 5, so there might be a video-related timing issue.

Ski or Die intro sounds okay in SVN; seems about the right speed.

Attachments

  • Filename
    ski_000.mp3
    File size
    865.55 KiB
    Downloads
    16 downloads
    File license
    Fair use/fair dealing exception

Reply 2 of 6, by krcroft

User metadata
Rank Oldbie
Rank
Oldbie

Here's a recording from Cloudschatze:

Featuring SN76496 "3-voice" tones, noise-channel drums, and 4-bit playback of PCM digital samples.
Audio recorded directly from a Tandy 1000 RL system, with additional stereo-chorus and EQ effects applied.

https://www.youtube.com/watch?v=I8_z_CI37JE

DOSBox has it right on 😀

Reply 3 of 6, by almeath

User metadata
Rank Member
Rank
Member
krcroft wrote on 2021-08-01, 02:11:

https://www.youtube.com/watch?v=I8_z_CI37JE

DOSBox has it right on 😀

Very interesting. The sound output on my speakers (iMac) sounds slightly “rougher” but almost identical to that recording. However, I do hear a high pitched ring in my recording that is not in the video - does anyone else hear that? I think I’ll boot into Windows 10 to see if the ring occurs there too.

It seems that perhaps there was no default Tandy sound, and each model may have offered its own variations, depending on its specific chip sets and what the particular game made use of? I noted the following comment below the YouTube video:

“ The Tandy 1000 RL uses Tandy's PSSJ-2, "Bonanza" chip, which incorporates an NCR 8496 megacell, and is described as having a different noise-channel pattern than the TI variants.”

Unfortunately I only seem to have a standard Tandy 1000 or 1000HX available in PCem, not the model used for the recording in the video. I cannot actually get the emulated HX to boot at the moment. It makes me wonder whether the slower and softer playback was normal for the original Tandy 1000.

EDIT: I just tested in Windows 10 with the same DOSBox configuration, and the high pitched ringing sound I mentioned is even more pronounced.

Reply 4 of 6, by Great Hierophant

User metadata
Rank l33t
Rank
l33t

You can get Skate or Die to play its samples properly in a fork of DOSBox which has the sampleaccurate patch applied. If the patch is complied into the fork, it works well when set to "true" with samples which play back on the Tandy or Adlib sound chips. It will corrupt PC Speaker sample playback, so it must be set to "false" with those games.

Attachments

  • Filename
    dosbox_000.mp3
    File size
    2.43 MiB
    Downloads
    15 downloads
    File license
    Fair use/fair dealing exception

http://nerdlypleasures.blogspot.com/ - Nerdly Pleasures - My Retro Gaming, Computing & Tech Blog

Reply 5 of 6, by almeath

User metadata
Rank Member
Rank
Member
Great Hierophant wrote on 2021-08-01, 17:02:

You can get Skate or Die to play its samples properly in a fork of DOSBox which has the sampleaccurate patch applied. If the patch is complied into the fork, it works well when set to "true" with samples which play back on the Tandy or Adlib sound chips. It will corrupt PC Speaker sample playback, so it must be set to "false" with those games.

Thanks. Apparently DOSBox-X is the only current branch that supports this feature. I searched around on this forum and also Github, but could not find any diff patches for use with SVN. There are discussions from around the start of this year that indicate the code would have to be re-worked to make it possible to apply to SVN or other branches (as DOSBox-X's mixer is forked from an earlier branch of DOSBox). If anyone has successfully ported this feature to an SVN-compatible branch, please let me know. 😀

Reply 6 of 6, by almeath

User metadata
Rank Member
Rank
Member

The other thing I have realized is that in Skate or Die, the intro music needs the "sampleaccurate" feature enabled, but the in-game events use standard PC speaker music. So if you use that feature you will get distorted music in the main game. Seems you cannot have accurate music for both at the same time, unless there is a future fix that prevents this patch from distorting the standard PC speaker output.