Is there a comparison of VDP replacement options

[broettger]

I was looking at replacing the video chip in another TI-99/4a console.

 

Previously I put an F18a in and have been very happy with it.  Now I see the Tang Nano and Pico9918 both seem to be good alternatives at a lower price.  Are there other alternatives that I missed?
 

Has anyone put together a comparison of the options that lists the pros and cons of each?

[broettger]

Main difference I have found is that the Tang has hdmi and the pico9918 does VGA. F18a is also VGA only.  
 

I see there is some pico 2 (RP2350) based solutions that do DVI-D over the hdmi connector and some projects (InfoNES) have figured out audio as well using the inexpensive Pico DVI sock. Makes me wonder if the pico9918 could do the same if it switched to the 2350

Edited November 19 by broettger

[broettger]

Are there any comparability differences between the three  available solutions?

 

I did see one video that compared the gpu performance of them.  

[visrealm]

For everyday use, you can use any of them. No real difference.

 

For most F18A enhanced games and demos, you can also use any of them. If you want to ensure 100% F18A compatibility, go with the F18A.

 

I can't comment on the Tang as I don't have one. I have PICO9918s and an F18A Mk1.

 

On the RP2350... the RP2040-powered PICO9918 is already capable of running all of the current F18A demos as far as I've seen. I've also built RP2350 powered PICO9918s and they are technically faster than the F18A, but there's still not much benefit to it at this stage until software makes better use of it.

 

I might do a DVI (HDMI) version eventually. But, both RP2040 and RP2350 powered versions could do that.

[+arcadeshopper]

F18A - the standard FPGA contains a fast 9900 GPU and the 9918a emu. advanced features, built well and QC'd by the designer

Tang - you get to build it yourself, hdmi out.. 

Pico9918 - slower, cheaper fine if you don't want to use the full speed gpu

 

[visrealm]

23 hours ago, broettger said:

I did see one video that compared the gpu performance of them.  

This is the video - running Tursi's GPU mandelbrot

 

This is the GPU performance difference - with the PICO9918s running at standard (for PICO9918 F18A mode) clock rates:

 

 

Then there's this one showing the effect of increasing clock speed on the PICO9918 (these are all RP2350)

 

So, overall, there's not much in it. And in reality, there aren't any GPU-intensive titles I'm aware of where it matters.

 

Edited November 20 by visrealm

[nuxi]

On 11/19/2024 at 3:12 AM, visrealm said:

For everyday use, you can use any of them. No real difference.

 

For most F18A enhanced games and demos, you can also use any of them. If you want to ensure 100% F18A compatibility, go with the F18A.

 

Which, just to be clear, means you should always grab whatever is cheapest/easiest to get hold of if you're just looking for a non-composite solution for a machine other than a TI99, Nabu or a Colecovision, as those are the currently only two that use the enhanced modes. 

Edited November 21 by nuxi
Nabus now have some 80 column software

[globeron]

F18A has been working great from my experience. 

 

I just saw this video, not sure if that fits in our TI-99/4A, but you never know 🙂 https://www.ti.com/video/6363874287112?HQS=epd-dlp-null-dlpc84xx_p2-paidlinked-v-inplatform_dlp_gen_int-ww_en_awr

[HOME AUTOMATION]

This is a chip-set for LCD projector, image improvement. Been around for quite a while. Also known as MMT, Micro-Mirror Technology.

I have two, packed away.

[JB]

On 11/27/2024 at 1:26 PM, globeron said:

F18A has been working great from my experience. 

 

I just saw this video, not sure if that fits in our TI-99/4A, but you never know 🙂 https://www.ti.com/video/6363874287112?HQS=epd-dlp-null-dlpc84xx_p2-paidlinked-v-inplatform_dlp_gen_int-ww_en_awr

Older DLP projectors do have composite inputs, so you could hook a 4a up to one.

 

With a modern VDP replacement, you could connect to a modern DLP projector through HDMI.

 

Neat devices. The light shines onto a "digital micromirror device", which is a chip with a crapton of pivoting mirrors for pixels. Depending on the mirror's angle, light either goes to the projection lens for display or into the enclosure to be discarded.

They're apparently quite common in laser printers these days. 

[+OLD CS1]

17 hours ago, JB said:

Older DLP projectors do have composite inputs, so you could hook a 4a up to one.

I have two DLP projectors with composite inputs.  One does not sync to the signal well, so it only displays black and white, while the other treats the signal as interlaced and produces fantastic tearing.  But, still a direct connection.

 

17 hours ago, JB said:

With a modern VDP replacement, you could connect to a modern DLP projector through HDMI.

All of my projectors have a SVGA input, as well, so the F18A works beautifully with them.

 

17 hours ago, JB said:

Neat devices. The light shines onto a "digital micromirror device", which is a chip with a crapton of pivoting mirrors for pixels. Depending on the mirror's angle, light either goes to the projection lens for display or into the enclosure to be discarded.

I am befuddled by this part,and how I can watch the power consumption of my projector vary based upon the brightness (or darkness) of what is on-screen.  I figure if it is just discarding light after it is produced, I should see a stable consumption, but I do not.

[Tursi]

I loved my DLP projector when I had it.

 

The power consumption is probably caused by the switching of the mirrors. Since the pixels are either ON or OFF (ie: the mirror has two states*), it gets brightness by flickering. Also, unless you have a three chip unit, all the mirrors are also flipping in time with the color wheel.

 

* - as far as I know. I am pretty sure they can't do angles, that would mess up the light.