First time poster. Many thanks for all the work done on PCem. Quite an amazing project. Looking forward to the next official release!
I'm relatively new to PCem, as such, not sure if this has been reported before (or if I'm in the proper forum) -- please let me know if that's the case.
Sound FX Lag Issue:
I noticed while playing Doom (shareware 1.9) that all sound FXs seem to lag by half a second (guesstimate). I compared with the game running in DosBox (latest SVN) as well as on real hardware (IBM Personal Computer 330 -- P133 with 16MB RAM). DosBox *might* lag by a few micro seconds, but it's not as bad as on PCem.
PCem always runs at 100%. Tried different motherboard / CPU configurations (486, P75, P133) with different sound cards (with appropriate SB drivers). Tried inside DOS 6.22 and MS-DOS Mode (Windows 98 SE).
Host Machine:
My host machine is running Windows 10 on a i7 4770K CPU.
Repro Steps:
1- Simply launch Doom (shareware 1.9) and navigate up and down in the main menu. Notice the graphics update immediately upon user input but the sound updates a little later. The same occurs in-game when pressing shooting.
2- I also experienced the same lag in the Doom (shareware 1.9) setup utility (although the sound output is actually PC Speaker beeps). To repro, simply run setup and navigate up and down and press Enter / ESC to hear the various beeps (high pitch, low pitch). Notice the lag.
3- I also played around with the pro_org.exe program that comes with the SBPro install disks. The lag also happens in there when playing the organ, maybe even more so noticeable.
4- Lastly, I tried running Doom with only PC Speakers as Sound FX. The lag is still there.
Latest code still seems affected:
Following a guide on the forum, I managed to compile the latest code from bitbucket (up until commit # 4e95feb). Still able to reproduce the lag. Might be good if someone could confirm that they were able to repro as well (in PCem 11 and latest).
Let me know if you want to see a side-by-side video with the real hardware vs PCem vs DosBox.

Thanks,
Mr.Nacho