Asteroids Saucer sounds missing.....

Powerplayfec

Active member
Joined
Dec 2, 2008
Messages
266
Reaction score
63
Location
KANSAS CITY, Kansas
Hi. Well I am working on an Asteroids board today. Fixed a bad RAM chip and got the game up. Only problem now is that neither of the saucers have any sound. Checked C46 and it's OK. Should I replace the 555? Is there anything else that would make those particular sounds not be made? Thanks.
 
Hi. Well I am working on an Asteroids board today. Fixed a bad RAM chip and got the game up. Only problem now is that neither of the saucers have any sound. Checked C46 and it's OK. Should I replace the 555? Is there anything else that would make those particular sounds not be made? Thanks.

Do you hear the Saucer Firing?

EDIT: If you don't hear the saucer firing or moving, you might want to start at M10 and see if that is bad.
 
Last edited:
I think all of the saucer sounds use the +12 v. So I would check to see that you have that as well. The 4016's need the +12V
 
Funny, I was just looking at the schematic for this the day before yesterday.

Yes, the saucer sounds use +12V, but so does the sound for your ship's shooting (and perhaps other sounds, I didn't look throroughly). So if your shooting sounds are good, I'd guess that the +12VDC is good. But it'd be good to check it anyway.

Regarding the "M10" reference... I'm not sure if you're referring to the LS259 that's at that location on the -01 thru -04 boards, or the 4016 that's there on the -05 & -06 boards. The former latches ALL of the sound signals; the latter is a bilateral switch controlling the saucer firing sounds. If you meant the former, it will be at M11 in -05/-06 boards. If meant the latter, it's at location M9 if the OP has an older (-01 to -04) PCB.

In any case, there a quite a number of components in the circuits that generate and control the saucer "noise" and saucer firing sounds. Atari's schematics on this are quite good, and include a high-level description of how the circuits work. What tools do you have to test & diagnose? A scope? logic probe? Or just a DMM?
 
Last edited:
Funny, I was just looking at the schematic for this the day before yesterday.

Yes, the saucer sounds use +12V, but so does the sound for your ship's shooting (and perhaps other sounds, I didn't look throroughly). So if your shooting sounds are good, I'd guess that the +12VDC is good. But it'd be good to check it anyway.

Regarding the "M10" reference... I'm not sure if you're referring to the LS259 that's at that location on the -01 thru -04 boards, or the 4016 that's there on the -05 & -06 boards. The former latches ALL of the sound signals; the latter is a bilateral switch controlling the saucer firing sounds. If you meant the former, it will be at M11 in -05/-06 boards. If meant the latter, it's at location M9 if the OP has an older (-01 to -04) PCB.

In any case, there a quite a number of components in the circuits that generate and control the saucer "noise" and saucer firing sounds. Atari's schematics on this are quite good, and include a high-level description of how the circuits work. What tools do you have to test & diagnose? A scope? logic probe? Or just a DMM?

I guess it would help to know what rev board he has :)
 
Asteroids saucer sound

Hi and thanks for the replies so far. I have what I would assume is an original A034986 pcb with no revision number. Yes there is the saucer firing sound. Just no warbled tone for them flying across the screen. Now I did substitute a 2114-2 RAM in place of the original AM9124BPC chip at E2. That at least got the pcb to run.
 
Good work on the RAM replacement.

AFAIK, they all had dash-numbers. I think the first ones were the -01s. They were usually hand-written in ink on the PCB. Are the IC columns on the PCB labeled 1-12 (-01 thru -04) or 2-13 (-05 & -06)?
 
asteroids saucer sound

Well I expected to see a handwritten revision number but alas there is none. The columns are numbered 1-12 (even though the #12 isn't seen).
 
OK, then you've got a -01 thru -04. Most likely a -02 or -04, as the -01 and -03 were the PROM versions, and all I've ever seen are EPROM varieties. Note that these are "dash numbers" and are subtlely different from "revision letters," which Atari also used on their PCBs just to make things extra confusing. The revision letter is usually screened in a corner in yellow, IIRC.

Next, does your PCB have just a single 8-pos DIP, or does it also have a 4-pos DIP?
 
Best educated guess without putting a scope on things, I would say it's the 566., possible the 555.

If you have a logic probe check to make sure the enables are toggling, for that matter you could check the 555 with a logic probe too.
 
saucer sounds

Well I changed the 555 at R10 and it didn't help. R10 is the one right? Don't have a LM566 in stock to try yet. Board has been worked on before and the 74ls164 at R9 had been changed.
 
My pcb has just the one 8pos DIPsw. and uses PROMS

OK, the ones before the 4-pos dipswitch were revs A & B. To nail it down:
At C4, do you have an LS191, or something else?
At F5; LS193 or LS191?
At B7; LS161 or LS191?

In any case, you'll want to get either the 1st or 2nd printing of the manual, and the 1st printing schematics, from here:
http://arcarc.xmission.com/PDF_Arcade_Atari_Kee/Asteroids/

Sheet 2B has the sound circuitry.

Yes, the 555 @ R10 is the one that feeds the saucer sounds. As you'll see on the schem, other components in there include the quad switch @ N10, the hex inverter @ N9, a couple of transistors, and of course the 566.

LM566s aren't very common, nor cheap.

You should be able to eliminate the latching IC and the inverter buy grounding pin 12 of N9. If that makes your sound, everything downstream is OK, and you issue is either N9 or M10. If that doesn't make your sound, the problem lies in the actual sound-generation circuit.
 
Saucer sounds

OK, the ones before the 4-pos dipswitch were revs A & B. To nail it down:
At C4, do you have an LS191, or something else?
At F5; LS193 or LS191?
At B7; LS161 or LS191?

In any case, you'll want to get either the 1st or 2nd printing of the manual, and the 1st printing schematics, from here:
http://arcarc.xmission.com/PDF_Arcade_Atari_Kee/Asteroids/

Sheet 2B has the sound circuitry.

Yes, the 555 @ R10 is the one that feeds the saucer sounds. As you'll see on the schem, other components in there include the quad switch @ N10, the hex inverter @ N9, a couple of transistors, and of course the 566.

LM566s aren't very common, nor cheap.

You should be able to eliminate the latching IC and the inverter buy grounding pin 12 of N9. If that makes your sound, everything downstream is OK, and you issue is either N9 or M10. If that doesn't make your sound, the problem lies in the actual sound-generation circuit.

Well this is what i found on this board
C4= 74161
F5=74193
B7=74161

I tried enabling the sounds via N9 and nothing happened.

I had totally forgot that Atari schematics gave pretty detailed theory of operation.
Still haven't figured it out though.
Thanks for your help so far.
 
OK, sounds like you have a Rev B, -01 or -02 PCB. Are you sure it has PROMs? Like a memory at J2 & K1, but not at C1? My "EPROM" I was lumping in OT-PROMs (which are just eproms without the erase window). If you've got a PROM PCB, I really want to get a good high-res photo of it :)

Yeah, old Atari schematics are awesome.

If you've got a logic probe, you could perhaps use CMOS mode to try probing thru the circuit to see where it goes dead... A scope would be ideal. But if you have neither... I try swapping the 4016 if you've got one handy and/or order a 566.

arcadechips.com has them.
 
saucer sounds

I took some hi-res photos of the board and if you give me an email address I can send them. I noticed that this version of the program puts up "ASTEROIDS BY ATARI" instead of "COPYRIGHT 1979" at the bottom of the screen. I haven't any test equipment other than a DMM. I usually just pay others to do the hard fixes. I'll replace the other chips in the curcuit and see what happens.
 
Email address sent by PM. Thanks.

The "Asteroids by Atari" vs "Copyright 1979" difference is actually the software revision, which is technically seperate from the PCB revision and dash-number. But the one you have is the older of the two software revisions. In addition to the text on the bottom of the screen, there are some bugfixes in the later revision, and it's apparently a little harder.

You can read a little about it here:
http://www.brasington.org/arcade/products/adl/ast-rev2a.jpg

EDIT:

Correction, there are 3 known versions of the Asteroids code. Here, from a cache of MAWs:

The revision 1 version has an invulnerability glitch, which allows players to hide the ship in the upper corners of the screen (in the score) and be invulnerable to collisions. Revision 1 also has a bug which affects thrusting. If the ship reaches full velocity moving down or left, and continues thrusting while rotating to the opposite direction, the ship will not slow down from the full velocity that has been reached in the original direction.

The Rev.2 version says '1979 Atari' at the bottom of the title screen, instead of the 'Asteroids by Atari' that was displayed in Rev.1. Also, the invulnerability glitch of Rev.1 is corrected.

The Rev 4 version :
1) Allow small saucer to use wrap-around feature,
2) Allow small saucer to fire immediately when entering the playing area, and
3) Prevent the intermittent loss of 3rd initial on 10th highest score.
 
Last edited:
Back
Top Bottom