VOGONS


DOSbox Adlib sound regression?

Topic actions

Reply 40 of 46, by heechee

User metadata
Rank Newbie
Rank
Newbie

Let me add that once I exchanged my Awe32 with an Awe64 Gold all my old games with Adlib problems (i.e. Secret of the Silver Blades, Hard Nova, Dynablaster, etc...) played their music flawlessly!
Remember the article didn't say the OPL chip was omitted, it was integrated. Perhaps with a couple of tweaks..?

Reply 41 of 46, by HunterZ

User metadata
Rank l33t++
Rank
l33t++

jez: I don't understand how Qbix's explanation has anything to do with cycles...

Reply 42 of 46, by jez

User metadata
Rank Member
Rank
Member

No? With a low number of cycles, the game is able to detect Adlib, which is the preferred sound hardware and so it uses it. However, I presume that it is not able to detect it with a high number of cycles, and so falls back to rather nasty CMS sound.

I got this assumption from jal's comment, "DOSbox doesn't emulate hardware on a timing level, I think, so [not getting Adlib sound when running Prince of Persia 1 at a high speed] might be [the result of] an interaction between DOSbox and the AdLib emulation (which is taken from Mame)."

== Jez ==

Reply 43 of 46, by Zorbid

User metadata
Rank Member
Rank
Member

IIRC, some early games didn't detect Adlib on fast PCs.

Reply 44 of 46, by HunterZ

User metadata
Rank l33t++
Rank
l33t++

Zorbid: I do remember Sierra games having troubles with that. I remember that it was a standard practice to kill time by playing with I/O ports a certain number of times while waiting for the Adlib to respond, which resulted in a much shorter delay on faster computers.

Reply 45 of 46, by jal

User metadata
Rank Oldbie
Rank
Oldbie
HunterZ wrote:

Zorbid: I do remember Sierra games having troubles with that. I remember that it was a standard practice to kill time by playing with I/O ports a certain number of times while waiting for the Adlib to respond, which resulted in a much shorter delay on faster computers.

Well, since the ISA-bus used in PC's in those days had a standard speed, reading I/O-ports resulted in a standard delay. So it is not true that faster PCs had much shorter delays. The problem was that some games (and I'm not sure Sierra did this too) detected speed in a less processor speed friendly way (e.g. empty loops), and also that some hardware used non-standard bus speeds (resulting not only in problems with detecting hardware, but the operation of it in general, causing unstable PCs).

JAL

Reply 46 of 46, by jal

User metadata
Rank Oldbie
Rank
Oldbie
Zorbid wrote:

IIRC, some early games didn't detect Adlib on fast PCs.

True, but that shouldn't effect (affect?) DOSbox too much, since DOSbox doesn't time its I/O to the CPU speed (or better: the cycle speed), so the timing problem with higher cycles is a result of a different technical problem, though resulting in the same hardwaer 'malfunction'.

JAL