Project: HDMI/DVI out for STFM

[Steve]

Nice @Icky I like how the port has a hole that lines up with the motherboard to give added strength (I was wondering about that until I noticed)

[Darklord]

Board looks neat, clean and compact. Very nice.

I'll second BikerBob - if there's a list please put me down on it using permanent marker.

[JezC]

I'll put myself on any early orders list too if possible!

Really like the look of this little board.

[Elliot]

Sorry late to this and skimmed over a number of posts to get an idea of what it does but going to ask (probably again) - sorry.

So this is not just a breakout board for HDMI, etc it is also a replacement Shifter Chip? I think I saw it can do higher resolutions, I ask about memory access, for higher resolutions does it use the main memory still (I assume loading the bus more) thereby any changes by the CPU (and I suppose (if fitted) by the BLITTER) take effect immediately?

Does it have its own memory and resolutions that it can run, if so how is that accessed? If so this would effectively be a "classic graphics card", is it compatible with any current VDI drivers? I know the Atari 8 bits and C64 have had similar upgrades that can (I think) natively support legacy resolutions but also have the ability to run resolutions from their memory.

Sorry if these questions are crap, I am at my limit what is possible with the Shifter. I do remember there were a couple of upgrades available back in the day, one was an overscan (no idea how that worked) and another to give 4096 (or maybe 32k) colours by using two Shifter chips.

[Icky]

Sorry late to this and skimmed over a number of posts to get an idea of what it does but going to ask (probably again) - sorry.

So this is not just a breakout board for HDMI, etc it is also a replacement Shifter Chip? I think I saw it can do higher resolutions, I ask about memory access, for higher resolutions does it use the main memory still (I assume loading the bus more) thereby any changes by the CPU (and I suppose (if fitted) by the BLITTER) take effect immediately?

Basically this is a shifter chip recreation that has a direct digital upscale to a resolution supported by HDMI monitors / TVs. There are no higher resolutions. To do this with an existing shifter you will have to modify the bus speeds, MMU and GLUE. Similar to the thread @troed worked on to expose extra resolutions https://www.exxosforum.co.uk/forum/viewt ... 1619#p1619

Does it have it's own memory and resolutions that it can run, if so how is that accessed? If so this would effectively be a "classic graphics card", is it compatible with any current VDI drivers? I know the Atari 8 bits and C64 have had similar upgrades that can (I think) natively support legacy resolutions but also have the ability to run resolutions from their memory.

No this is just an STFM shifter with some additions such as sound mixer to get the sound out through the HDMI port. There is a description of its features over on the Phoenix E-Boards thread - https://www.exxosforum.co.uk/forum/viewt ... 106&t=4585

Sorry if these questions are crap, I am at my limit what is possible with the Shifter. I do remember there were a couple of upgrades available back in the day, one was an overscan (no idea how that worked) and another to give 4096 (or maybe 32k) colours by using two Shifter chips.

Once we get the board working 100% we can possibly look at additions such as the STE palette and attempt something like the 32k mod. Only issue here is no software currently out there exists to use such mods. e.g. to have a game use a 32k palette it would have to be written to use the underlying hardware.

[exxos]

GEM can display over scan screens for higher resolutions without to much trouble. I don't know about colours. I assume the VDI can open a workstation for 16 colours at higher resolutions, but we are a while away from those issues yet. Sadly nobody wants to help with the projects, so @Icky is mostly figuring out stuff on his own.

The shifter is just one step among many. We can make the shifter do whatever we want. The next problem is it needs faster access to RAM. I already have a 68000 running up to 75mhz. We are working on a FPGA MMU so we can get faster RAM. Then the next problem is getting GEM to use the extra bandwidth for higher resolutions and colour depths. We can have high speed 14MB ST-RAM where it will render boosters and graphics cards are obsolete.

[Elliot]

Okay so it is a Shifter replacement, helpful if yours dies but most likely used for the HDMI output.

Will it support rasters, overscan, sync scroll, etc? I am not sure how complex the Shifter is.

What BUS access does the Shifter socket have? Can it access hi-mem (other than the norm) registers? Very possible I am completely of the mark with how this chip works. That said I think I remember a bunch of RAM upgrades using this socket which would kind of suggest it has a bunch of address and data lines.

I know this is not the main goal but could the project potentially be sent other data and treated as a graphics card or is this idea simply not possible here with this method? I know if "we" could do this we would probably just end up with one demo converted to use it and that is it, at best some GEM resolutions which would only work with "responsible" apps.

[exxos]

The shifter doesn't really do much. The MMU is what drives the data to it. The shifter has a few internal registers for stuff and that's it. There's already demos shown *somewhere* which work perfectly .

Graphic cards are a bodge on top of the CPU. Need drivers like NVDI and are less compatible with software and very slow. There is just no need for it. The ST need an faster ram and more of it . Faster RAM = more data you can push to the shifter which either goes into higher pixel count or colours.

Our goal is to be as backward compable as possible with the original ST but offer more of what is possible. We are basically building a new ST from the ground up.

[Smonson]

Once we get the board working 100% we can possibly look at additions such as the STE palette ...

The STE palette has always been supported actually.

Also, it's a bit of a technicality but there's a 256-colour mode as well, but the pixel clock is halved. So it's practically useless since nobody's ever successfully got the HDMI mod to work on a 16MHz machine.

[Darklord]

Also, it's a bit of a technicality but there's a 256-colour mode as well, but the pixel clock is halved. So it's practically useless since nobody's ever successfully got the HDMI mod to work on a 16MHz machine.

Wait, what? I don't understand? So any accelerated Atari fails with the HDMI mod?

So it's useless with anyone with an AdSpeed, Turboxx board, Pak 68/3, etc installed?

I thought the STacy that was built with a TF board worked with this mod?

Thanks.