CD32 + FMV with A riser

68030 + SDRAM + IDE

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terriblefire
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Re: CD32 + FMV with A riser

Post by terriblefire »

Maximilian wrote: Fri Jan 24, 2020 1:15 am Didn't know the schematics from the FMV were online.

You are right, there is a switch in the STV8438CV for Amiga / C-Cube output.

Does that mean Ext_Video is always low if an FMV unit is placed?, makes sense....
Could not find it in the crappy PDF schematics i found , maybe there are better ones out there?
I was able to get the ESM up on the DB23 with the FMV in place. So probably not always low?
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darksun9210
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Re: CD32 + FMV with A riser

Post by darksun9210 »

Someone was kind enough to send me this on another forum when i was digging for info on the FMV card. it's pretty interesting, a presentation by the main engineer on the FMV stuff, starting with the CDTV which should have been a prototype for the CDTV-CR, instead of the CDTV being released and the CDTV-CR getting shelved, then the CD32 and FMV development on from there, through to the prototype CD1200 and the fun with that.



so as i can figure, the FMV card switches off the normal amiga output to the composite and s/vhs encoder, and routes the normal amiga analogue RGB into itself. it then does the video mixing into colour 0 and routes the whole lot back into the amiga's video encoder.

no funky stuff happens on the amiga side, all it's good for is overlaying buttons and control stuff on screen - as much as i understand it
terriblefire
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Re: CD32 + FMV with A riser

Post by terriblefire »

Thanks.

Judging by the setup the FMV doesn’t pass this back to the edge connector. I guess they never expected anyone to put a DB23 on the riser. Either way I think the answer is to replicate the switch on the riser
———
"It is not necessarily a supply voltage at no load, but the amount of current it can provide when touched that
indicates how much hurting you shall receive."
terriblefire
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Re: CD32 + FMV with A riser

Post by terriblefire »

Think i've had an epiphany.

On the riser we should be using EXT_AR, EXT_AG, EXT_AB with appropriate passives.

This would pick up the standard video when U36 is ON.

This would pick up the FMV + Mixed Video when U36 is OFF.
———
"It is not necessarily a supply voltage at no load, but the amount of current it can provide when touched that
indicates how much hurting you shall receive."
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