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R-Type Leo missing sprites

Ace`

Ace`

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I just picked up this R-Type Leo board I've got it booting but there are sprite issues. The sprites are missing completely I noticed the roms (00,10,20,30) weren't getting addressed this was an issue with JP3 making poor contact. With this fixed (and in the correct position) they're getting addressed now but still no sprites. I *think* the data is making it through the G22 custom okay as using a video probe I am able to see some of the missing sprite data on the 74F153 pin 12 @IC26. It's almost like the sprite layer isn't getting selected? I tried replacing all the PALS on the mainboard with GALS and this made no difference so these all seem to be good. Anyone got any ideas? hopefully it's not the G22. <X
 
Ace` said:
I just picked up this R-Type Leo board I've got it booting but there are sprite issues. The sprites are missing completely I noticed the roms (00,10,20,30) weren't getting addressed this was an issue with JP3 making poor contact. With this fixed (and in the correct position) they're getting addressed now but still no sprites. I *think* the data is making it through the G22 custom okay as using a video probe I am able to see some of the missing sprite data on the 74F153 pin 12 @IC26. It's almost like the sprite layer isn't getting selected? I tried replacing all the PALS on the mainboard with GALS and this made no difference so these all seem to be good. Anyone got any ideas? hopefully it's not the G22. <X
Click to expand...
I believe you mean GA22, and yes it fails all the time.
 
Yeah the roms are checked and yes I did mean GA22. The sprite data seems to be getting through the GA22 though from what I was seeing with the video probe. I am guessing schematics don't exist?
 
Ace` said:
Yeah the roms are checked and yes I did mean GA22. The sprite data seems to be getting through the GA22 though from what I was seeing with the video probe. I am guessing schematics don't exist?
Click to expand...
What is a video probe? I know video probes used to get images from unreachable places (inside an engine block, in the sewers, etc.).
And no schematics but you don't really need them, you have mostly address and data lines coming from/to the custom chip and a few control signals.
 
I had never heard of it and don't know anyone using that method. I still don't see when it can be really useful by opposition of using a logic probe, a scope or simply dumping the ROMs.
I guess I missed that repair log from caius. Must be the only one he actually uses a "video probe".
 
At M92 boards there is a jumper on the main pcb which needs to be present - if not no sprites at all.
Cant remember the exact jumper location though.
 
mastercello said:
At M92 boards there is a jumper on the main pcb which needs to be present - if not no sprites at all.
Cant remember the exact jumper location though.
Click to expand...
It's JP3. It's mentioned in the OP.
 
Yep that jumper also got me in the past.
Other than that I fixed this sort of thing by looking at the sockets for the graphics roms and making sure they all had good pin connectivity, which they didn't.
But ouch yeah.. for -all- sprites to have gone simultaneously is clearly something else further down the line.
 
^ One of the sockets on my R-Type Leo conversion is loose and I just need to tap it so the sprites appear correctly :)
 
Sounds like you need to carefully bend the pin legs out on each side (ie. with a metal or plastic ruler), so when re-inserted the ROM is more firmly wedged in place.
 
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