Perhaps you can upgrade your RAM. But don't use more than 32 MB with your L2 cache configuration.

Disruptor wrote on 2022-12-23, 16:57:

Perhaps you can upgrade your RAM. But don't use more than 32 MB with your L2 cache configuration.

Thanks for the feedback. If I come across a nice pair of 2x 8MB, I might. I think 16MB would be ample amount here.
But for the record I ran a max allowed amount of 64MB (2x 32MB FPM) in this system and the only trouble associated with it found was incorrectly detected negative value in Norton SI. Neither MEMMAKER nor games were confused by it.
Despite the cacheable amount I also did not notice any performance problems in that scenario.

September 2023 update:
RAM is upgraded to a single 32MB FPM module (Texas Instruments TMS417400ADJ-60)
Bus frequency increased to 40MHz, the CPU runs as DX4-120 now. With two VLB cards I am not seeing any instability.

With the new specs Duke Nukem 3D should be playable but I ran into a stuttering problem discussed in 2016 when using DreamBlaster S2 regardless of audio quality, screen size or detail settings.
This post by user orcish75 suggested Duke3D is faster in Windows 95 than in DOS and yes that fixed it. The game runs well in 320x200 with SB16 sound and DreamBlaster MIDI with reported FPS of 20-30.

So the system runs Windows 95 OSR1 now (the one without Internet Explorer, USB, etc.) and I also tested some Windows games:

• Breakthru! (Spectrum HoloByte, 1994)
• Lode Runner: The Legend Returns (Sierra, 1994)
• 3-D Ultra Pinball (Sierra, 1995)
• Aladdin95 (East Point Software, 1995)

  The attachment aladdin 95 epi.jpg is no longer available

All running well.

Trident 9440AGi even has a Windows95 driver that claims some acceleration.

Doom fullscreen (from DOSBENCH pack) is 1710 realtics = 43.6FPS.

Are you sure it's an AMD Am5x86 "DX5-133" I'm pretty sure it would run 133 MHz at 33 MHz FSB and 160 at 40 MHz?

H3nrik V! wrote on 2023-09-25, 12:18:

Are you sure it's an AMD Am5x86 "DX5-133" I'm pretty sure it would run 133 MHz at 33 MHz FSB and 160 at 40 MHz?

I’m 100% sure, it runs at 3x 40MHz right now. To use 4x multi I would need to upgrade bios (see notes above)

Bruno128 wrote on 2023-09-25, 12:34:

H3nrik V! wrote on 2023-09-25, 12:18:

Are you sure it's an AMD Am5x86 "DX5-133" I'm pretty sure it would run 133 MHz at 33 MHz FSB and 160 at 40 MHz?

I’m 100% sure, it runs at 3x 40MHz right now. To use 4x multi I would need to upgrade bios (see notes above)

Ah, I get it ... Apparently I TL;DR'ed that part 🤦 That's a weird quirk, though

Which BIOS version did you try?

I have this one, which ran fine with Am5x86 as i remember.

PC-Engineer wrote on 2023-10-07, 05:13:

ran fine with Am5x86.

Hi. Yes, that's the one, ver. 1.4. You are right, 133 does indeed work at normal speed. Did turbo function work for you though? Lack thereof was the deal-breaker for me as I mentioned in the op. If you know how to make turbo work with this bios, please let me know.

Post updated to reflect current configuration.
Current TODO is finding CD-audio cable with MKE connector.

Noting that I just completed The Dig playthrough on this PC.

A few things to make DIG95 playable on 486

Flickering mouse cursor: change linear accelerated Trident driver for SciTech Display Doctor 6.53.

Choppy cutscene playback: tick “Sync data transfer” option in device manager (for SCSI CD-ROM in Windows 95).

Slow voiced dialogue loading: increase RAM to 16MB to reduce swapping.

Build update: Added Roland SC-55 (gameport to MIDI cable). New photos in OP.

Why I decided not to do PAS16 with Sound Canvas:

• Unlike Jazz16, Pro Audio Spectrum 16 doesn't have any Windows 95 driver configuration that emulates MPU-401 on 330h (2015 post by badmojo). Meaning DOS games ran from within Windows can't use it. Windows games with MIDI work, however I quickly got hanging note bug requiring GM reset (2018 post by RetroBoogie)
• While MVSOUND.SYS DOS TSR does support MPU-401 emulation and SoftMPU is reported (2014 post by j^aws) to work with PAS16, there is a buzzing, clicking sound whenever there is MIDI activity (even if cable is disconnected). In Windows it doesn't happen so it's not hardware fault.

So I added a generic ESS 1868 card for its bug-free MPU-401 interface. This results in a known (2019 post by dionb) resource conflict because of PAS16 always using 388h as control port. If you choose to ignore it the sound will work in Windows but then you get a VXD related BSOD on shutdown. One of the standard ES1868F Windows 95 driver configurations however doesn't use this port and the conflict is gone but then it also doesn't provide MPU-401 emulation on 330h.

From this useful Pro Audio Spectrum Windows 95 FAQ (external url) I took the idea to set up DOS games via .PIF shortcuts individually specifying autoexec.bat / config.sys (advanced properties). Granted, this causes a soft reboot on every game launch but on the other hand I can also configure memory per game. I'm using combinations of ESSCFG.EXE and MVSOUND.SYS depending on what kind of SB emulation is best suited. Cards are connected via line-out - line-in.

That all being said PAS16 remains primary playback device for the reasons:

• No hiss, good 16bit audio quality
• SCSI
• PC speaker signals trap (I often play in headphones)

For DOS, latest MVSOUND version 3.26 download: (2019 post by Horun)

The system plays Duke3D very well in full screen with PAS sound + Sound Canvas music.
Also tested Lost Vikings (SCC-1 setup choice) and Supaplex (Combined SB + Roland setup choice) - all good.

PC-Engineer wrote on 2023-10-07, 05:13:

Which BIOS version did you try?

Hi I made progress on this. The turbo switch functionality breaks (freeze / suspend) not because of the BIOS update itself as I thought in 2022 but because of JP18 in 1-2 (Write-back cache).
I used the latest BIOS from November 1995 again, setting JP18 to 2-3 and the AMD-X5-133ADW now runs at 40x4 with L1 cache set to Write-thru. System is stable and fast and most importantly the Turbo function works correctly.
Turbo button slows down to 486DX-33 levels and pressing Ctrl-Alt-minus slows it further to 386DX-25 levels. Unlike some Pentium boards this hotkey combo also works in Protected mode (Win95) and on-the-fly.

DRAM timings: 4-3-3-3, 1WS. Cache timings: 3-1-1-1, 0WS.

On the side note I also installed a 6X SCSI CD-R drive that reads burned media better. Trantor Media Vision SCSI controller is based on NCR 5380 which has PIO data transfer rate of 690 kB/s. It remains to be seen what happens now when the drive itself is slightly faster than the controller throughput but in brief testing I didn't notice any problems.

Updating OP with new photo.