You can add Curse of Enchantia to your tests.

so I take
a. Companions of Xanth
b. Gods
c. Heart of China

are "good" titles to do tests with? I am interested in doing the same on my PS1/pro, K6-II and 5x86/133 pc's...

Malik wrote:

Why? What is the matter here?

Just a hunch, but I suspect that the LAPC-I is getting an "Exc. Checksum Error." Depending on how the sound drivers have been written, this problem occasionally occurs on my P5-166MHz system, which has an 8.25MHz ISA bus clock. If I drop the system down into "compatibility mode" (~25MHz, 386-ish), the playback issues cease.

Try Police Quest III with the various motherboard combinations. Any differences?

rebortmo wrote:

You can add Curse of Enchantia to your tests.

Any particular problem with this game and LAPC-I?

keropi wrote:

so I take a. Companions of Xanth b. Gods c. Heart of China […]
Show full quote

so I take
a. Companions of Xanth
b. Gods
c. Heart of China

are "good" titles to do tests with? I am interested in doing the same on my PS1/pro, K6-II and 5x86/133 pc's...

Errmm...these were the games that I've noticed the problems crop up with, in the said motherboards.
In the case of GODS and Heart of China, both games upload samples like the explosions and the flying witches' death wails in GODS and the Sea Gull's call heard in the very first game screen in Heart of China along with the sea waves sounds. The opening title of Heart of China instrumental is also distorted.

I suppose all other games (which I haven't tested yet - like Wing Commander I, II) that upload samples should also face similar problems in the said motherboard.

Cloudschatze wrote:

Just a hunch, but I suspect that the LAPC-I is getting an "Exc. Checksum Error." Depending on how the sound drivers have been written, this problem occasionally occurs on my P5-166MHz system, which has an 8.25MHz ISA bus clock. If I drop the system down into "compatibility mode" (~25MHz, 386-ish), the playback issues cease.

Try Police Quest III with the various motherboard combinations. Any differences?

It is interesting to see how the ISA bus clock affects the LAPC-I. I do have Police Quest III, and I'll do some further tests..

Many games that work only with intelligent MPU-401 doesn't really use IRQ2, but Curse of Enchantia does.

"how the ISA bus clock affects the LAPC-I" would be best tested with a board that allows to specify isa clock in bios. It is often done by dividing PCI clock: you can choose sometimes even from pci/12 to pci/2

Gigabyte 586TX2 motherboard (Socket 7, intel TX chipset -Titanium II, tried both with my P133-S and a P166 MMX) : Games which upload samples to the LAPC-I - example GODS, Heart of China - are unable to play the uploaded synths/samples properly. It's like using the MT-32 emulation using AWEUTIL in an SB AWE card - wrong sounds.

I've just managed to make the LAPC-I work properly in this motherboard - all the correct notes and all samples played back correctly :

I just set the 8-bit I/O Recovery Time to 8. (It was originally set at 1 in default. The values range from 1 - 8. And the value "NA" comes before 8.)

I didn't try other values. I just thought of maximising the recovery time. I rebooted again and again and tried back the games, just to make sure that this was the factor that caused the LAPC-I to malfunction in this board. Games tested : Heart of China and GODS. (Both games caused the previous problems.) Both now play as they were intended to.

This is with P55c 166-MMX cpu, with both external and internal caches enabled, with 256MB EDO RAM @ 60ns. No other settings were altered.

EDIT : BIOS : Award 4.51g, and the 8-bit I/O Recovery Time is found at the Chipset Features Page.

Malik wrote:

I've just managed to make the LAPC-I work properly in this motherboard - all the correct notes and all samples played back correctly :

I just set the 8-bit I/O Recovery Time to 8. (It was originally set at 1 in default. The values range from 1 - 8. And the value "NA" comes before 8.)

Awesome - congratulations! 😀

Could you please try Curse of Enchantia.
You just run setup
than game
and in intro there may be no music
although sfx in game may work. There will be water dripping of of the ceiling, a guard shouting, doors opening, dropped key, everything on the first screen after intro, you don't have to do anything, just skip the intro with esc.

I was testing many games with many boards and this was the most problematic one.

@retro games 100 : Thanks! It was merely a chance occurence! (Out of frustrations, maybe!) 😀

A quick update :

Done preliminary run tests of Police Quest III and Curse of Enchantia :

Police Quest III - No problems playing the roland sounds. All the sounds and music appear to be correct.

Curse of Enchantia - Won't load the game, maybe some incompatibilities with this particular board.

Curse of Enchantia - try it with dosbox first (maybe it wasn't installed properly or sth like that, (generally problem of the game not board)) try to run without soud/music, with sb soud/music etc. and try some other boards later too

Tried with no sound. The game still does not load. Tried with different memory configurations - emm,qemm,qhimem and basic himem with no smartdrv loaded. Still no luck. Maybe I'll try with a different board later.

try with DOSBox first (as it is the easiest to configure)

Enchantia - works in dosbox. Will try with my 486 and put up the result..

@robertmo:

I've installed Curse of Enchantia in my 486. And it....WORKS! 😁

486 Specs :

AOpen AP43 Motherboard
64MB RAM (FPM)
MusicQuest PC MIDI Card at IRQ 9 connected to the CM-500
AWE32 CT3990 @ IRQ 7
Microsoft Mouse using Serial Port @COM3 IRQ 4
S3 Virge

Seems like Curse of Enchantia can live with the IRQ 9 redirected?

i think it is obvious that game works with 486

I would be rather more interested whether it works with faster mobos, for example this one
"2.) ASUS P3B-F Slot 1 Motherboard (440BX) with the same components as above : No problems in any games"
that you claimed works properly with all games.
(I wonder what would be the fastest PC that can handle LAPC-I properly with all games, i haven't had any success with my PIII (BX) mobo so when i saw your BX boards working properly I wondered whether they really are PIII working properly with LAPC-I)

btw i think every game works with irq 9/2

Some more things I noticed in terms of LA synth playback recently :

Parts in focus here : Music Quest PC MIDI Card connected to Roland CM-500.

Game tested : Heart of China

1. Epox MVP3C2 motherboard (Super Socket 7) with AMD K6 2 400 MHz. When the bus speed is at 100MHz, the notes are all wrong.

When I disable the internal cache however, the notes start playing correctly.
(Disabling the internal cache, using Speedsys, it shows the system performing somewhere in the 486DX 50MHz region.)

I wish the 8-bit I/O recovery time option is available in the bios of this motherboard. That would have made me test with full speed.

2. DFI CA61 motherboard (Pentium III Socket 370) with Coppermine 1GHz processor. I reduced the bus to 66MHz and the speed was at 500MHz (66MHz x fixed 7.5 multiplier).

Result : All LA notes in Heart of China played CORRECTLY.

I didn't do more comprehensive tests yet, but the preliminary outcomes seem to fall into the following conditions:

a. It does not matter if the total system speed is high.
The LA synth seems to be more influenced by the actual bus speed.

b. MT-32/ LA synthesis plays well without any workarounds at the bus speed of 66MHz.

c. On faster systems, it is very useful to have the 8-bit I/O recovery time in the bios to make LA sounds play properly.

Systems that do not have that option in bios may be able to play correct LA notes by reducing the bus speed to 66 / 33 MHz.