IndivisionECS will have dual video output!

[Schoenfeld]

would it not be possible to link these 2 FPGA addons together externally (an extra data-bus?)

That would be possible if I'd make two new designs: One for the Agnus-socket and another for the Denise socket. Re-using the existing Indivision ECS design would not be an option, as there's neither room, nor IO-pins left for an additional data bus.

Doing two new designs that go together anyway doesn't make sense either, especially with the fairly artificial separation of the Amiga chipset into three chips (granted, they couldn't get the amount of transistors on a single chip back then). So today you'd take a single FPGA, place it into the Agnus socket and do Alice *and* Lisa in there.

However, you still would be limited to a 16-bit data bus from the processor, so one important AGA property - the 7MB per second performance on chipmem - would not be there if you don't own an A3000. If you'd want to reach that, you need to put the CPU directly on that AGA-card as well, resulting in "almost an A1200" on that expansion board that's mounted in the flaky 84-pin socket. In other words: We're back to a new motherboard.

Jens

[Schoenfeld]

I have been thinking about the RGB cable too since the RGB cable gives very crisp output, but as I understood the image on a 50" plasma which have VGA input is going to look better from an Indivision than from an A500 with an RGB cable connected to it?

I do not know how TV's work but LCD/Plasma scale the image to fit the resolution of the TV, and sometimes this scaling can look bad.

First of all, not all TVs support the 15khz horizontal/50Hz vertical frequency that an Amiga sends out. Although these are the frequencies that have been used for TV for decates, some "modern" TVs require PC frequencies at their RGB input. If your TV supports these low TV frequencies on the PC input, you're lucky and a basic display is possible without Indivision ECS.

You might still want to think about an Indivision, there is a number of advantages:

- scanline emulation
If you really plan on using your Amiga on a modern Plasma TV, you don't see the classic scanlines that a lot of games are designed for. Games mostly look better if you watch them on a CRT, but the flicker and radiation makes it a fairly unhealthy experience to your eyes. Modern displays are a lot better for your eyes, but you're trading the classic look. Indivision even gives you the classic look on a moden display.

- proper de-interlacing
Some TVs do de-interlace, which is mostly called "100Hz technology" in Europe. However, they often use comb-filters on top of that, which distorts certain pictures that are pretty normal on an Amiga workbench. Indivision AGA leaves the image unchanged and sends it to the display exactly the way it was sent from the computer.

- Graffiti built-in
Maybe not the killer-application, but it increases the number of colours on a lores screen. Programs that are written for the Graffiti will display the correct gfx instead of the broken-looking command&pixel data that would be displayed on a normal TV

- HighGFX support
HighGFX is a package that adds more screenmodes to your Amiga, but it does it at a price: Sync frequencies are extremely off the standard, and only a small amount of true multisync monitors can really display these modes. With Indivision ECS, the output frequency is always at VGA levels or higher, so the probability of a good display will be increased by magnitudes.

- PAL output at 62.5Hz
If your TV is an NTSC product, it may have a minimum vertical frequency of 60Hz, just like many PC monitors have. Unfortunately, many games and demos on the Amiga are switching to PAL, mostly un-noticed by the user if they used a 1084 monitor before. If you're trying to give a PAL signal to an NTSC TV, you will most probably see a "mode not supported" (or similar) warning, if you see a warning at all. Indivision ECS has a mode where the output frequency is not just twice as high (as it has been on other flickerfixers for the past 18 years), but 2.5 times higher. This results in 39kHz horizontal and 62.5Hz vertical frequency, which is well within the range of most monitors and TVs with PC input. Although this is asyncronous to the Amiga's vertical blank, tearing effects are fairly low due to the syncronisation between the pictures. If your TV supports 50Hz, you can even de-grade to the classic "x2" flickerfixer type and have no tearing at all (provided that your TV doesn't introduce tearing on it's own).

- ECS Denise built-in
Last but not least, you upgrade your computer if you don't already own a Hires Denise (the ECS Denise). Even if you only have an ECS Agnus, but an OCS Denise, the computer will find an ECS Denise and offer you the new screenmodes associated with ECS, such as productivity and S-Hires modes. Productivity may not be all that interesting, as it was an attempt to get around the flickerfixer problem (which is solved by Indivision anyway), but S-Hires gives you quite some resolution on the workbench - ever seen 1280 by 512 pixels flicker-free on an almost-unmodded Amiga? Note that the ECS modes will only be dispalyed correctly on the Indivision output. While the 23-pin RGB output remains active, it will display garbage in a setup where you use an ECS screenmode with an OCS Denise.

We even have more in the works, but that's nothing I can reveal at this point. It's not yet clear if we can really have these features in the product, but I'll keep you updated here. The hardware is final, and while Oliver keeps developing, I have launched production today: All parts have been confirmed and PCB production has been started. If all goes well, assembly will be done during the last week of this month.

Jens

[Schoenfeld]

Supergreat!

So... now you have time for a CD32 clockport adapter?

Unfortunately, that has never been on my todo-list. I have to finish Chameleon for the C64, and I also need to work on a huge non-retro project.

Jens

[Schoenfeld]

As I understand it, the Amiga sets up a 1 bitplane bitmap, and then the graffiti treats every 8 (actually I believe it was less than this) pixels as bits in a single chunky pixel.

Almost - Graffiti does this for four bitplanes at a time. Separation of the four bitplanes is done by setting a fixed colour palette in Denise, so each bitplane is sent out through one of the four digital-video-out bits of the 23-pin RGB port. If you read the Inside_Graffiti file on my support site, you'll find that the "internal" colour palette only uses the MSBs of the three colour values, plus the LSB of the blue value. Having the data separated that way, the hardware comes fairly easy and fits into two GALs (crammed, but it fits!).

The data format in Amiga chipmem is chunky, but not linear, as pixels from left-to-right are arranged in bitplanes 0-1-2-3-0-1-2-3-0-1-2-3 and so on. Still, manipulation of a single pixel only takes a single write, which makes things quite fast.

You're right that a true linear display is limited to 160 pixels (plus overscan).

Jens

[Schoenfeld]

What affect (if any) does the scan-rate conversion have on the smoothness of the scrolling?

Like I wrote earlier, tearing will be introduced if you scan-up from 50Hz to 62.5Hz. However, it's not as bad as with ordinary scanrate converters, as the "cut" is always happening on the same spot (or two spots, to be precise).

Does the VGA cable provided reach the spot on the rear of an A500(+) below the floppy drive where it is suitable to drill a hole?

The VGA cable is the same part as for the AGA version, it's too short to fit under the A500 diskdrive. A longer cable would have caused more cost (which is a sensitive subject, as we learned in this thread), and it would have probably affected picture quality.

My first try for a "really nice" mod would be to remove the RCA audio connectors and add a 3.5mm audio jack, which is way more common these days. The space freed by the RCA jacks is big enough for the VGA connector.

As the IndivisionECS is a re-creation of the Denise chip in an FPGA, what are the prizes for finding the first bugs?

(I'm sure it is upgradable, right?)

Sure it's upgradable - it has a 1MByte flash that can hold up to eleven different FPGA cores. Depending on the screenmode, different cores are loaded automatically. On a change, the monitor loses sync for a fraction of a second and comes back with the new screenmode.

As for Denise bugs.. good idea with the prizes. I'll think of something - how about T-Shirts and vouchers :-)? (ducks and runs away....)

Jens

[Schoenfeld]

Which brings us to the question of whether indivision-ECS will fit along with Apollo-630... will it?

The Apollo 630 even conflicts with the A603 memory expansion. Maybe I'm repeating myself, but Apollo accelerators should be trashed regardless of their supposed value. I do not guarantee anything if an Apollo accelerator is in the same computer as my hardware. I've had WAY too much support work in the past years because of flaky accelerators, overheating computers, failing power supplies. Everything solved by replacing the accelerator - I should have introduced this policy much earlier, would have saved a few years of my lifetime ;-)

Jens

[Schoenfeld]

wouldn't be possible to output PAL at 75Hz instead of 60Hz?

That requires more memory performance, which is not fully tested at this point. The memory itself can do it, and the Fifos inside the FPGA are also rated much higher than what we're currently using them at, but I cannot guarantee that unless we have implemented it with the memory chips that will be mounted on the final hardware.

The memory vendor I chose has recently made a die-shrink from 110nm down to 70nm (unit is "nanometers"). Sample chips should arrive this week, then we can start testing if they work at the required frequencies. If they do, such a higher scanrate conversion would be possible. If they don't, we'll be limited to 62.5Hz for PAL.

If they keep their promises, we might even do 100Hz PAL, but they will have their reasons for not selling the chips to me unless I approve the samples.

Wouldn't be possible to show the odd frames twice? so you show the following frames: 1, 1, 2, 3, 3, 4, 5, 5, 6, 7, 7, 8, 9, 9, 10... perhaps that helps to smooth the movement (or breaks interlaced screens)

It would actually be less smooth, as such a method requires a double-buffered framebuffer. You'd wait for a full frame to be transferred, then switch. I'd much rather update the picture when it really happens; anyway, we have lots of unused memory, so double-buffering might be an option we could add - switchable at the user's choice.

Jens

[Schoenfeld]

but.. but.. I didnt ask "will it work", I asked "will it fit"

It won't fit, the conflict between Apollo 630 and A603 is of mechanical nature. The A603 is quite big and also occupies lots of space inside of the A600.

Jens

[Schoenfeld]

some news from the production site:

I've been a little nervous about the first dual-sided production run on the new machines (new since 2008), but it was all going flawlessly so far. Backsides have been assembled last week, and we're now tweaking the machines for the other side. If all goes as planned, the manual assembly (DIP sockets, jumper and VGA connector) can start next week.

Time to place your pre-orders!

Jens