ET4000 issues solved..

Time for a Break.. =)

Bodge wires are always a good thing. 😉

This looks like a rather small modification! Good job!

Fix for graphical glitches with some cards..

4D Sports Driving - Recording Test with Zoom Q2n (Thanks Dreamblaster!)

https://youtu.be/ejSy6LPTeEk

Using PC-Speaker In too to achieve 4 Voice Sound.

More News, Testing Software and TSR development continues 😀

TSR:

Fully featured Testing Programm for 3 Voice Chip:

oooohhhh very nice software! kudos!

Here on
https://github.com/JKnipperts/TNDY

I have a Lo-Tech Tandy 3-voice card in my 486 and when I run King's Quest 2 or the Sierra On-Line demo programs using the Tandy voice, I have graphical glitches. Other King's Quest games, including Space Quest 1-2, and Police Quest EGA are working fine.

You need to add 2k2 Resistor from READY to VCC on the SN76489.
The LoTech Card is missing the PullUp for SN76489.

Also add the 68pf as shown above to reduce noise a bit.

Maybe this will fix your issues ?

2k2 is 2.2K Ohms, right? Also, about the PC speaker mixer for the card. How can I get that to work? I can only get a standard 8 Ohm speaker to work or the squeaker cam speaker and I would like to direct the PC speaker to the Tandy card, and the volume is turned up as well. I will give this a go soon as I need to buy those components on Digi-Key.

The hotfixes are on page 13 the first post of where they need to be soldered onto, correct?

Tandy 3 Voice Sound - SN76489 ISA Soundcard Project

Yeah 2k2 kOhms

The PC-Speaker in of the Tandy Card works on some Machines but not on all, you should get it working if you link the signal in with a capacitor.
otherwise it will result in a short circuit and maybe damage something.
i don`t have the original lo-tech card anymore 😒

This is used on some SB Vibra Cards:

Normally any Speaker should work on the Speaker Output, but if its too silent you can connect a 10uf Capacitor from Pin 1 to Pin 8 on LM386 to rise the gain to maximum.

bjwil1991 wrote:

I have a Lo-Tech Tandy 3-voice card in my 486 and when I run King's Quest 2 or the Sierra On-Line demo programs using the Tandy voice, I have graphical glitches. Other King's Quest games, including Space Quest 1-2, and Police Quest EGA are working fine.

Okay, that's interesting. I had not run into any graphical glitches yet with my card, but apparently it only occurs with some software (makes me wonder why). I'll test my card specifically with KQ2 and see if I get the glitching as well.

matze79 wrote:

Tandy 3 Voice Sound - SN76489 ISA Soundcard Project […]
Show full quote

Tandy 3 Voice Sound - SN76489 ISA Soundcard Project

Yeah 2k2 kOhms

The PC-Speaker in of the Tandy Card works on some Machines but not on all, you should get it working if you link the signal in with a capacitor.
otherwise it will result in a short circuit and maybe damage something.
i don`t have the original lo-tech card anymore 😒

This is used on some SB Vibra Cards:

Normally any Speaker should work on the Speaker Output, but if its too silent you can connect a 10uf Capacitor from Pin 1 to Pin 8 on LM386 to rise the gain to maximum.

Thank you. I will buy some caps and resistors and fix the issues. My GPU is a Cirrus Logic CL-GD5428 VLB integrated on my Packard Bell Pack-Mate 28 Plus. Also, would it be a good idea to use a 47pF capacitor over the 68pF? There's a MicroCenter in my area that sells lots of resistors and capacitors, but no 68pF ones.

47µF will help but not as much as 68pF will. 100pF will work but probably begins to muffle sound. Two 47 is series and then parallel over 3rd 47pF should get something around 70pF which will be fine.

I've been following this topic for a while, although I personally do not like old hardware, this topic is awesome !

Thanks for sharing 😁

Tiido wrote:

47µF will help but not as much as 68pF will. 100pF will work but probably begins to muffle sound. Two 47 is series and then parallel over 3rd 47pF should get something around 70pF which will be fine.

For the series, that means the two are connected to each other and parallel means opposite ends connect (ex: AA battery compartments)?

Like this :

I added both the caps (3x 47pF caps to be ~70pF) and the 2K2 resistor and I still have graphical glitches in King's Quest 2.

Do you also have Graphical Glitches with PC-Speaker ?

Do you run Card on XT or AT System ?

If you don`t have glitches with PC-Speaker and If you run on 386 + do you also get glitches if you run with TNDY.COM TSR with the Card located on other Adress ?

Add least you will no longer suffer from compatibility problems with sound blaster cards (Non-16) with the 2k2 resistor 😉