First post, by wbahnassi
- Rank
- Oldbie
Hi, I'm having a depressing problem in my build.
The build:
* P233-MMX
* M571LMR motherboard
* 3.5"+5.25" drives
* 1 CD drive connected to secondary master
* 1 Transcend 4GB CF card as HDD on primary master
* SB16 ASP CT1740 with A220 I7 D1 H5
* Embedded VGA SiS
* 32MB RAM
* DOS 6.22
The problem:
Certain games freeze the system when playing FM and digitized sounds simultaneously. Not all of them. Lemmings 2 and Mortal Kombat exhibit the issue. DOOM is fine. Might & Magic 3 intro is fine (FM+Speech). In the games that freeze, FM only is ok. Digitized sounds only is ok. If you enable both, then it will freeze as soon as an FM note is played along with an SFX.
The freeze is funny too. The game freezes, FM note hangs, but the digital sound is played to its end.
If you have both FM and SFX enabled, you can keep playing until you cause an SFX to play.. then the freeze will occur within a few attempts. If you change FM to MT-32, no freeze happens.
What I've tried:
* Pretty much all BIOS options, cache toggles, speed controls, safe options, disable COM/LPT, PnP settings
* Slow down CPU to 120MHz via BIOS
* SetMul L1D
* Swap SB16 with a SB AWE64 and used UniSound to init it
* Skip Config.sys/Autoexec.bat
* Swap slots
* IRQ5 instead of IRQ7 via jumpers
* DMA3 instead of DMA1 via jumpers
[EDIT - more things I tried]
* QEMM386 instead of EMM386 or nothing
* Running the games from within Windows 95 DOS box
* Swap SB16 with a SBPro2 CT1600
* Switch to a 256MB CF card instead of 4GB
* Win98 boot disk
* Physically disconnect the CD drive
[EDIT2 - even more things]
* Swap PSU with a different one
* Jump/Unjump JP3 - enables/disables on-board sound chip
* Reseat RAM
* Flash all 1Mbit BIOSes from The Retro Web using Uniflash
* Base address in sound card 0x260 instead of 0x220
[EDIT3]
* Jump JP8 - when jumpered, disables on-board MODEM (part of the sound chip)
[EDIT 4]
* Disable/enable LAN jumper and LAN 5V jumper
* ISA VGA card and disable on-board VGA
* On-board sound card in DOS
* Remove SoundPro chip (mobo wont POST)
Nothing fixed the problem. It's not the sound card itself as another SB AWE64 exhibited the same issue on the machine. The games are OK too as they work fine on a different build. The only thing I couldn't try is BIOS flash, as I don't have the tools to write one myself.
I also haven't tried using a standard HDD instead of CF, but I doubt it to be the culprit.
I'm really stumped. What could cause such strange behavior? Help!