I/O Board
Re: I/O Board
so I'm a bit confused. This new revision will require the use of the HDMI port for analogue signals? Would that mean that we would no longer be able to output video from both the VGA port and the HDMI port at the same time?
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- Atari freak
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Re: I/O Board
Its the digital I/O board that is removing Analog out.djsquare wrote:so I'm a bit confused. This new revision will require the use of the HDMI port for analogue signals? Would that mean that we would no longer be able to output video from both the VGA port and the HDMI port at the same time?
The I/O board rev 6.1 will still have Analog output.
People just simply have more choices now. If you still care about 15khz analog out get the 6.1, if you mainly just use HDMI out get the digital I/O board.
Re: I/O Board
I use both, often in tandem. I'm not sure what I make of this new revision. Analogue signals are important to me. I use one of my MiSTer for RGB/HDMI and other for component/HDMI output. If lets say down the road we actually do make use of dual SDRAM functionality then the ability to use both analogue signals in tandem with the HDMI will be lost. I can't say I like the sound of that, only time will tell how it plays out. I do appreciate new hardware being developed of course, it just something to think about
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- Atari freak
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Re: I/O Board
djsquare wrote:I use both, often in tandem. I'm not sure what I make of this new revision. Analogue signals are important to me. I use one of my MiSTer for RGB/HDMI and other for component/HDMI output. If lets say down the road we actually do make use of dual SDRAM functionality then the ability to use both analogue signals in tandem with the HDMI will be lost. I can't say I like the sound of that, only time will tell how it plays out. I do appreciate new hardware being developed of course, it just something to think about
I think having the potential of better Ram bandwidth for future cores is more important than having dual outputs. Anyways, I wouldn't worry about it too much. You'll likely be just fine for the foreseeable future.
Re: I/O Board
yeah you're probably right. Thanks for the input
Re: I/O Board
I need analog output, where can i buy the new 6.1 ioboard?
Thank you.
Thank you.
Re: I/O Board
MiSTer never claimed as a dual output. Although it's possible at some extents, it's limited due to shared resources.
Analog output with zero delay is possible through Direct Video, so it's not lost with Digital I/O board. Basically this is how MiSTer should look originally, but i'm learning and such feature as Direct Video came out only recently after some of experience from working on MiSTer.
There is a potential limit of SDRAM bandwidth preventing to make more advanced cores, so secondary 40pin connector is mostly for secondary SDRAM but currently it's not used. May be even dual MiSTer could get some potential. Anyway this is for further expansions for more advanced cores.
Analog output with zero delay is possible through Direct Video, so it's not lost with Digital I/O board. Basically this is how MiSTer should look originally, but i'm learning and such feature as Direct Video came out only recently after some of experience from working on MiSTer.
There is a potential limit of SDRAM bandwidth preventing to make more advanced cores, so secondary 40pin connector is mostly for secondary SDRAM but currently it's not used. May be even dual MiSTer could get some potential. Anyway this is for further expansions for more advanced cores.
Re: I/O Board
While the dual output is nice to have as an option, it's only really needed for streamers. For regular users who need to switch between scaled and direct video frequently, I recommend using an HDMI matrix with two outputs, one can go to flat panel and the other to DAC, so all you need to do is toggle direct video mode on/off. So it's worth the tradeoff for the potential of dual SDRAM.
And then the potential of a dual MiSTer setup is even more interesting. Now imagine dual MiSTer + dual SDRAM for some real blast processing!
And then the potential of a dual MiSTer setup is even more interesting. Now imagine dual MiSTer + dual SDRAM for some real blast processing!

Re: I/O Board
This is really exciting honestly. You just opened up a lot of future potential for the platform. Even for streamers, analog splitters are a thing, no real need for dual outputs directly driven by dedicated boards.Sorgelig wrote:MiSTer never claimed as a dual output. Although it's possible at some extents, it's limited due to shared resources.
Analog output with zero delay is possible through Direct Video, so it's not lost with Digital I/O board. Basically this is how MiSTer should look originally, but i'm learning and such feature as Direct Video came out only recently after some of experience from working on MiSTer.
There is a potential limit of SDRAM bandwidth preventing to make more advanced cores, so secondary 40pin connector is mostly for secondary SDRAM but currently it's not used. May be even dual MiSTer could get some potential. Anyway this is for further expansions for more advanced cores.
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- Atariator
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Re: I/O Board
I’ll take dual misters for sega 32x cd 

Re: I/O Board
Very interesting! Just out of curiosity, did you build and already tested a secondary SDRAM board?Sorgelig wrote:There is a potential limit of SDRAM bandwidth preventing to make more advanced cores, so secondary 40pin connector is mostly for secondary SDRAM but currently it's not used.
Fx Cast: Atari St cycle accurate fpga core
Re: I/O Board
Yes. NeoGeo originally was dual SDRAM core. Project files for dual SDRAM still exist, although i didn't try it long time already.ijor wrote:Very interesting! Just out of curiosity, did you build and already tested a secondary SDRAM board?Sorgelig wrote:There is a potential limit of SDRAM bandwidth preventing to make more advanced cores, so secondary 40pin connector is mostly for secondary SDRAM but currently it's not used.
Framework also has definitions for dual SDRAM config.
Re: I/O Board
Sorry for the late response...paulbnl wrote:I traced these with a multimeter:
RX: Latch
TX: Clock
RTS: Zapper light sensor
DTR Zapper trigger
DSR: Serial
Thank you for finding this out!
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- Atari freak
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Re: I/O Board
Does anyone know what the Digital IO Board is, and how will it be different from the analog IO board.
Re: I/O Board
It's a "light version" of the analogue IO board, lacking VGA out. That's all.redsteakraw wrote:Does anyone know what the Digital IO Board is, and how will it be different from the analog IO board.
Re: I/O Board
It's not "light version". It's version with further expansion ability, and when expanded, it's a question which I/O board will be "light".yxkalle wrote:It's a "light version" of the analogue IO board, lacking VGA out. That's all.redsteakraw wrote:Does anyone know what the Digital IO Board is, and how will it be different from the analog IO board.
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- Atari freak
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Re: I/O Board
To be clear is this the same expansion port that the new OSSC pro will be using?Sorgelig wrote:It's not "light version". It's version with further expansion ability, and when expanded, it's a question which I/O board will be "light".yxkalle wrote:It's a "light version" of the analogue IO board, lacking VGA out. That's all.redsteakraw wrote:Does anyone know what the Digital IO Board is, and how will it be different from the analog IO board.
https://videogameperfection.com/2020/01 ... -is-coming
Re: I/O Board
I have no idea. I don't watch that project. Also there was no choice which port to free as SDRAM port is pretty much defined and used already.
Basically both ports are identical from electrical point of view.
I think it would be interesting to be able to add function of generic scaler of external source. Will see when that board will be available. But generally i don't expect that connector to be used solely for video input as MiSTer in general is self-contained device. So i expect it to be used for something more advanced giving some benefit to the project.
DE10 is not expensive, so it's always possible to use another board just for scaler. MiSTer itself gains nothing from this function.
Basically both ports are identical from electrical point of view.
I think it would be interesting to be able to add function of generic scaler of external source. Will see when that board will be available. But generally i don't expect that connector to be used solely for video input as MiSTer in general is self-contained device. So i expect it to be used for something more advanced giving some benefit to the project.
DE10 is not expensive, so it's always possible to use another board just for scaler. MiSTer itself gains nothing from this function.
Re: I/O Board
On the new digital I/O board, what are the three pins marked 3.3v IO6 and I/O used for?
Re: I/O Board
To switch the pin on connector between 3.3v and additional GPIO.
Re: I/O Board
Yes, I can see what it does, I am just wondering what it is used for?Sorgelig wrote:To switch the pin on connector between 3.3v and additional GPIO.
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- Atarian
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Re: I/O Board
Hi I'm having trouble locating the resistor arrays. Potentially dumb question but can we merely use combinations of double resistance such as 510R and 1K?
Re: I/O Board
arrays should be high precision (1% or better). 510*2 = 1020, not 1000. If you are satisfied by result then it's up to you.pseudobacon wrote:Hi I'm having trouble locating the resistor arrays. Potentially dumb question but can we merely use combinations of double resistance such as 510R and 1K?
510 is too high, you will get dark video. But again - if you find it acceptable, then it's fine.
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- Retro freak
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Re: I/O Board
As pointed out in previous post, looks like there's no supply of the 604ohm 4 resistor network 1% until July 2020 !
https://au.mouser.com/ProductDetail/652-CAY16-6040F4LF
Would there be an alternative to this we can substitute ?
https://au.mouser.com/ProductDetail/652-CAY16-6040F4LF
Would there be an alternative to this we can substitute ?
CAM / 3D Designer & Fabricator - Electronic Engineer
MisterFPGA stuff at http://caminventions.com
MisterFPGA stuff at http://caminventions.com
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- Retro freak
- Posts: 12
- Joined: Wed Jan 01, 2020 10:47 am
Re: I/O Board
As pointed out in previous post, looks like there's no supply of the 604ohm 4 resistor network 1% until July 2020 !
https://au.mouser.com/ProductDetail/652-CAY16-6040F4LF
Would there be an alternative to this we can substitute ?
https://au.mouser.com/ProductDetail/652-CAY16-6040F4LF
Would there be an alternative to this we can substitute ?
CAM / 3D Designer & Fabricator - Electronic Engineer
MisterFPGA stuff at http://caminventions.com
MisterFPGA stuff at http://caminventions.com