* edit the BK roms are fine, it was the speech chip, 55564 does not seem to be compatible with Black Knight and Alien Poker. Alien poker uses sound 3. see post 3 for 55516 vs 55564 *

Going through all the WMS sound and speech ROMs on IPDB and I have encountered a few issues. Most system 7 game downloads come packed with "sound 12" but I have found about eight different versions with the same "Sound 12" label. The manuals make mention of sound 5, sound 6, etc. Most on IPDB seem to be the right data but I have two sets I can't get to work right.

Alien Poker. On IPDB one ROM pack comes with "SOUND 2". A different IPDB ROM pack download comes with "SOUND 3". The manual says sound rom should be "white labeled", does that mean unique data for AP? When I pair sound 2 with the AP speech ROM I get no speech in test mode, speech is skipped. When I pair the AP speech ROMs with sound 3 I get silence during when speech should be playing in test mode. Same behavior with English Speech or French Speech ROMs. I am guessing this game has a unique sound ROM? Does anyone know what sound ROM goes with Alien Poker and any issues with the IPDB rom packs?

Black Knight. All IPDB ROM pack versions come with the same "sound 12". Manual says it should be "SOUND 5". In test mode I get silence when speech should be playing. In game mode I get some static at times speech should play. I think the sound ROM is right as I recognize some of the sound effects even tho I am testing in a firepower. If I use the French black knight speech ROMs it talks fine, I only get silence with the English black knight speech ROMs. Has anyone had trouble or success with the IPDB BK speech ROMs?

All the other game sound/speech ROMs from IPDB seem to be working ok. If you ever wanted to know what Thunderball speech sounded like...

BK SOUND 12 = DD2F
BK VIC4 = 07B5
BK VIC5 = DEE5
BK VIC6 = 0C08
BK VIC7 = DCB8

SOUND 3 = BDCA
AP VIC4 = NOT USED
AP VIC5 = 17B0
AP VIC6 = 6DE0
AP VIC7 = 0329

*deleted *

So it turns out 55564 is not directly compatible in all cases with 55516. Black Knight and Alien poker do not work with 55564 but all the other system 6 and 7 talking games seem to be ok with 55564. I desoldered a 55516 off of an original speech card and then Black Knight started talking just fine. I got 55564 from Rochester Electronics in two batches so they should be legit. Both are 55564-5 in plastic dip with one batch is 99 date code the other 96. I found one 55564 that tries to work if the temp is under about 70f. It starts out ok but within a few minutes, it heats up, becomes, garbled, and eventually goes silent. Hit the chip with cold spray and it starts to work again until it gets back to about 70f then it shits out again.

I just spent a bunch of money on 55564 that seems like it will not work in all games which sucks. There is a system 11 service bulletin for this speech chip I may try. Looks like it isolates pin 1 from +5v with a resistor.
https://www.ipdb.org/files/1308/Williams_1988_Jokerz_William_Service_Tip_For_Audio_Hum.pdf

If that does not work Black Knight and Alien Poker will not be supported by the replacement sound board until / if I find can 55516.

Alien Poker uses Sound 3, not Sound 2.
20210302_015756 (resized).jpg

I went with the 55564 because it was the only one I thought I could find NOS in bulk from a reputable place (~$7ea rocelec.com, they have like 10k). I actually did not even think to look at GPE for whatever reason but I see you have the 55532. I have not tried 55532 yet but I have a few system 11 games with a harris speech chip. I will look to see if any are 55532 to try as I seem to remember seeing them used by WMS. If 55532 works without changing anything else I may be trying to buy a large number from you. I will also compare the speech clock/data and see if I notice differences in BK and AP from the rest later. Maybe there is something easy I can still do to make 55564 work.

This sound board is doing great in regards to hum and noise, specially compared to later sys 9 and 11 games which always have lamp switching noise. The separate transformer tap and 12v supplies probably have a lot to do with it. I will check out the low pass filter too for the future though too.

Yep! The combo sound ROM is built around 32K of space. For 16K games the first half can be filled with FF and then the game data goes in the upper half. Just doubling the data seems to work fine too.

That ribbon cable with the tight bends for sure the single most commonly failure point of the sound + speech boards I encountered.

I am going to have to order a 55532 to test with. I could not find any around the house.

I checked and the BK, AP, AP French 55564 compatibility issue exists on the original hardware too. BK and AP cannot use 55564. Not sure about 55532 yet.

I found a HC3-55564 I wrote BAD on the tube it is in some time ago. I just tested it and it actually works fine. I must have been trying to use it in BK as that game was pretty popular when I fixed boards.

Yes, it works fine. Has a mid 80s date code and behaves just like the 90s ones as expected I guess.

My dual trace scope is an old school cathode ray. I guess I can take pictures of it. I have been meaning to buy a new digital one I can do things like export pic snapshots. When I need something quick i have a hand held scope (single trace) and rarely get the old CRO beast out.

Hot damn, you are onto something there. Held 27pF straddled across the chip legs and speech comes in but it is really scratchy. I grabbed a 150pF and then it talked and sounded fine.

200pF on three boards and all software is working fine across wide temperature. I can take the cap in and out of circuit on the as is working games like FirePower and there is no change in the speech sound / quality. Using HD6821P right now, will try 6820, 68A21 and 68B21 but guess it will work fine with any of them.

0.3¢ cap fix and calling it a day to work on other projects is tempting. I can hide the cap under the speech socket until next board revision. I do have two unused 4069 inverter gates on the other side of the PCB, but pretty sure I could make the route work. I guess I can Frankenstein a board with extra inverters in line to see if that helps instead of a cap.

It seemed like Rottendog had a MPU sound trigger PIA problem. This issue should not be related to Rottendog's BK problem the way I am thinking about it. Sound triggers are well separate from the CVSD clock/data, different CPU and PIA controlling it. Rottendog also emulated the CVSD chip on system 9/11 which does not sound as good at the real thing (which already is low quality).

Can tell WMS got better at coding the speech. FirePower is pretty crappy speech compared to later game like Thunderball, unless they where going for a compressed CB radio type of effect. WMS had multiple people working on the speech software. A lot of them snuck their name or initials visible in ASCII in U4 or U6. Saw at least three different names. One guy may have done things differently than others.

I wonder what Paul D. is up to.
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It is a software bug. Quench will have more info about the software.

My made in west Germany hameg scope seems to have died so I picked up a Siglent, maybe two of them.

Yellow is speech clock.

BK Stock software
20210310_160900 (resized).jpg

FirePower
20210310_160941 (resized).jpg
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Splitting hairs here but the software is what screws up the clock. Every other software works... so I will call that software bug. The hardware works fine with patched software which quench will have more info on.

Adding extra hardware to fix the software problem is a route that thankfully I will not have to go down.

20us time