Joust 2 - where has the speech gone?

Superully

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i finally got my Joust 2 up and running! however, i'm having a problem with the speech - as there is none :(. attract mode stays silent all the time, no screams from the "unbeatable?" pterodactyl, no "who will challenge me" when the title appears and no BEEP immediately after i turn on the game.

when i run the individual tests, ram / rom / cmos tests are all passed successfully, but when it comes to the sound test, it cycles through 15 individual sounds, but only sound 1 - 4 work, sounds 5 - 15 stay silent!

i don't know if J2 uses an individual chip for both sound and speech, but obviously there seems to be a problem somewhere somehow!
 
Check the data line from the main board to the sound board, You should see the individual lines pulsing. Likely causes for dropping sounds could be the high bits on the cable are not working or the interface chips to the 6821's are bad.

Check that the high bits on the cable are firing. If they are, then the issue is in the sound card. If they are not, try tracing the interface chips or if the 6821 is socketed (on some gen 3 boards it is on others it isn't), try swapping it out if the ports are not firing.

ken
 
Check the data line from the main board to the sound board, You should see the individual lines pulsing. Likely causes for dropping sounds could be the high bits on the cable are not working or the interface chips to the 6821's are bad.

Check that the high bits on the cable are firing. If they are, then the issue is in the sound card. If they are not, try tracing the interface chips or if the 6821 is socketed (on some gen 3 boards it is on others it isn't), try swapping it out if the ports are not firing.

ken

thx for your input, ken! now if i only knew what the heck you were talking about ;) this sounds damn complicated ...
 
sorry, have to dig this up again!

the problem still exists, because i haven't been able to follow through what ken has written above. is there someone out there with the patience to guide me through? i'd love to have the entire speech set available!
 
Ully,

Do you know how to read schematics? Do you have a logic probe?

Ken's suggestions are to isolate whether the problem is in the main board, the sound board, or the cable between. The main boards sends a sound command across the cable to the sound board.
 
Ully,

Do you know how to read schematics? Do you have a logic probe?

Ken's suggestions are to isolate whether the problem is in the main board, the sound board, or the cable between. The main boards sends a sound command across the cable to the sound board.

In this case, the sound circuit is integrated onto the board, so the first thing is to locate the 6821 PIA chip that drives the other PIA that drives the D/A coverter chip that actually makes the noise to drive the TDA that drives the speaker. Since there isn't actually Joust 2 schematics, the nearest thing is a set of Inferno schematics (according to legend, Inferno can be built using a Joust 2 boardset and populate them with Inferno ROMs). based on those schematics chip IC5 is the equivalent of the PIA on the ROM card and it drives IC4, the equivalent to the sound card PIA.

So if you want to find out if the signals are being generated from the CPU to the sound system, you need to throw your logic probe on pins 10-17 of IC5 for the output. If those are good, than check pins 10-17 pf IC4. If those are good, then you need to check the input to the TDA on pin 1. This is where an oscilliscope comes in handy, a fast sensitive DVM will work in a pinch. If you are are seeing the signal on the input and no sound, then replace the TDA 2002.

ken
 
Do you know how to read schematics? Do you have a logic probe?

i'm not really good at reading schematics, but i can follow instructions. those years at the military must have been good for something ;). so if you tell me what to do, i will (hopefully) be able to do it!

regarding the logic probe: i have a cheap one. have a look at the pictures of this is going to work. don't have an oscilliscope (yet), if i need one i'm going to buy one though!

5816865735_e127b5684e_b_d.jpg


5816865909_a7df3cf667_b_d.jpg


now tell me what to do, i'm ready to follow your orders! :)
 
The logic probe looks fine.

I just reread your original post and from that description, it sounds like the sound effects (flapping, screeching, bumping noises) work. It is just the digitized speech that is not working. AFAIK, the speech is generated in the outboard sound card.

I don't believe I have ever seen a schematic of the Joust 2 sound card so it is difficult to provide anything other than general advice. Check to make sure that the power is working to the card and that the input lines from the main boards are pulsing. After that you will need to trace the pulses though any logic chips until you get to the audio mixing section. If you are playing the sound effects, then it is likely that the audio mixing and output amplifiers are working, it is just the digital speech feed that is an issue.

ken
 
I just reread your original post and from that description, it sounds like the sound effects (flapping, screeching, bumping noises) work. It is just the digitized speech that is not working. AFAIK, the speech is generated in the outboard sound card.

I don't believe I have ever seen a schematic of the Joust 2 sound card so it is difficult to provide anything other than general advice. Check to make sure that the power is working to the card and that the input lines from the main boards are pulsing. After that you will need to trace the pulses though any logic chips until you get to the audio mixing section. If you are playing the sound effects, then it is likely that the audio mixing and output amplifiers are working, it is just the digital speech feed that is an issue.
ken

sounds nice, ken, but i don't know how to check whether something is pulsing or how to trace pulses. :(
if i provide you with a couple of pictures of the sound card (or whatever you need), would it be possible to guide me through the process?

thx a lot!!!
 
I'll need to look. I'm pretty sure that I have a complete Joust 2 boardset. I have just never built the wiring harness to test them, so I am not sure what the hookup to the sound card looks like.
ken
 
Sorry, I've been tied up for the last few days. We have a house that we were renting and decided we are going to try selling it. Our tenants moved out last week, so the past few days have been a crash course in getting a rental house ready to sell. I had to come back to work to rest up.....

ken
 
Well, it has taken way too long. I thought I had lost the Joust 2 sound card. It turned out I had put it in the Smash TV box because they look almost identical.

Joust 2:
attachment.php


SmashTV
attachment.php


The part numbers are different though:
SmashTV 5766-12130-00 rev D
Joust2 5766-12702-00 Rev B

ken
 

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