Any chance to add Tandy sound to ao486?

[thorr]

Last night I discovered that old AGI Sierra games like King's Quest I support Tandy music by launching the games with "sierra -t" and this produces much more pleasing music than the PC speaker. I was able to get this to work using Sarien in Windows 95, but it was way less than ideal and not an original gaming experience. Any chance that Tandy music can be added like the Gameblaster/CMS was?

[thorr]

Here are some examples:
https://www.youtube.com/watch?v=PKg762dr4kE
https://www.youtube.com/watch?v=ZummjWMN8-8
https://www.youtube.com/watch?v=nI7GWhZdcms
https://www.youtube.com/watch?v=24_DJ5bQXWM
https://www.youtube.com/watch?v=Yn0inNl79tI

Informational video:
https://www.youtube.com/watch?v=HZDqdRHvzp0

[thorr]

How to make a simple Tandy ISA card (probably without digital audio capabilities):
https://github.com/matze79/Tandy-Nano
https://www.vogons.org/viewtopic.php?t=74946
Another thread: https://www.vogons.org/viewtopic.php?f=62&t=54249

TSR to make it work with non-Tandy computers: https://github.com/JKnipperts/TNDY
Game Patches (can't currently test this link from work): ftp://ftp.oldskool.org/pub/TandySoundPatches/Games/

[bbond007]

https://en.wikipedia.org/wiki/Texas_Instruments_SN76489

Looks like this chip (or variation of) is also used in several computers and consoles that have existing MiSTer cores...

[sofakng]

I'd absolutely love to see this. I've also just discovered this fact about older Sierra games sounding better on the Tandy/PCjr than on the PC speaker.

Perhaps somebody can integrate the JT89 verilog code into ao486?

[jordi]

I'd absolutely love to see this. I've also just discovered this fact about older Sierra games sounding better on the Tandy/PCjr than on the PC speaker.

Perhaps somebody can integrate the JT89 verilog code into ao486?

Why not use them on pcxt core? They work on it.

[Caldor]

As Jordi said, this is the whole point of the PCXT core. It often makes more sense to make several different cores supporting different hardware instead of cramming it all into one.

If one person understands all the hardware, then it might work, but its not enough to make an FPGA that supports the hardware, Tandy also needs a BIOS ROM, so to get this to work dynamically with the core and support Tandy alongside Adlib and so on, a custom firmware would be needed.

[wellbow]

Perhaps somebody can integrate the JT89 verilog code into ao486?

I believe most (if not all) Tandy PCs that had the 3-voice chip had Intel 8088 CPUs that ran at 8 MHz (maybe 16 MHz?). Some of the older games that had support for the Tandy 3-voice chip (and didn't have support for OPL3 and SoundBlaster) also relied on the CPU clock for timing. This manifested as horrendous "bugs" where in-game sequences would run too fast or not allow the player enough time to complete a section before the game would trigger a death scenario; for example, on the intended hardware, you might have 60 seconds to enter a room and do something before another character would enter, find you, and capture you. But on a too-fast CPU, this could be only seconds. For what it's worth, this problem happened on much newer games into the 90s too; I remember Quest for Glory 4: Shadows of Darkness having a problem at the end of the game if it was ran on newer Pentium PCs.

Not all games that supported Tandy 3-voice had this problem, but it was common enough that a program called Mo'Slo was written in the 90s to essentially stay resident while your game was running and eat up CPU cycles, thus slowing your game down.

This problem is even listed on the AO486 core github: https://github.com/MiSTer-devel/ao486_MiSTer

Code: Select all

Core Speed and Options and Drivers

The default core speed is set to 90Mhz with both L1 and L2 caches enabled. This will 
give you the maximum speed for the release version of ao486. Some games, especially 
older games, are sensitive to speed and cache so you can change the speed options and 
cache to fit the game

As someone who today runs these games in DOSBox, I think you would enjoy these games more on a core targeted for the original hardware; not a much-newer machine that might be slowed down enough to run them.