Popeye Objects Missing Red

Richard48

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Popeye game uses three separate color circuits: text, background, and objects (anything that moves). The text and background graphics contain all three colors. However, the moving objects are missing the red.

The red video for objects comes from IC 3U (74HC175). There is video at the inputs to IC 3U, but the clock signal is a series of very short pulses and it does not change as the display objects move. Consequently, there is no output from 3U going to IC 5A (MB7052) to create the red object video.

The clock pulse comes from the ROHVCK signal on the CPU board and it is developed from the notAI, notBI, and notHBD signals. The notAI and notBI are squarewaves of 2.5MHz and 1.25MHz, respectively. The notHBD is a series of narrow negative pulses at about 15.75kHz.

Questions:
1. Can anyone verify what these signals should be?
2. Has anyone seen, and repaired this problem? If so, am I on the right track?

The RAM and ROM self test is OK, and I have pulled all socketed chips and cleaned the pins, as well as the edge connectors. The +5 supply is good and everything but the red for the moving objects is working fine.

Thanks,
Richard
 
Object pixel data consists of 2bpp image data (OBJV[1:0]) and a 6-bit color table index (OBJC[5:0]). There is no object 'red video' signal until the output of the MB7052 at 5B (not 5A).
 
Last edited:
Phil,
I agree that there is no red object video signal until the output of 5B.
Thank you for the additional information about the image data and color table index.
In this case, OBJC[5:3] is not being output from 3U. Power and ground are correct, there are active (changing) signals at the inputs to 3U (DO[27:24]), the CL pin is HI, and the clock pin shows a series of pulses that are low for about 10us and high for about 60us.
Any ideas?

Thanks again,
Richard
 
I'm not convinced 3U is at fault. Even if it the output was for instance, stuck at 0000, that would just limit the sprite colors to the first 32 entries of 5A/5B, which do contain colors with a red component.

Are you seeing activity on pins 10-12 of 5B? Are resistors R16, R17 and R18 ok? Is there continuity between the collective output of these resistors and R36?

Could you take a photo of the title screen and during the game?
 
Phil,
Yes, there is activity at pins 10-12 of 5B and resistors are well within tolerance. Continuity to Q1 base resistor (R36) verified. The red output circuit (Q1/Q2 and associated components) is further verified by the fact that text and background are producing red.

With activity only on pins 4 and 3 of 5B, only the first 4 (2^2) rows are being addressed. However, maybe this is okay and the other 28 rows are used at other levels in the game?

Looking closely, I can see that the hearts are light pink, so there is at least some red getting through. If I pull 5A, the objects are red. However, just not enough red, or at the wrong time, to display properly when combined with the blue and green from 5A.

Files showing title screen, game screen, and game screen with 5A removed are attached.

Richard
 

Attachments

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  • Game Screen.jpg
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  • Red Only.jpg
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Follow-up: Repaired!

Replaced both 5A and 5B as a set and all is well.
Yes, that should probably been done earlier, but I am new to these arcade games. Just an old TV/monitor tech trying to learn new things in retirement.
 
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