cyclone3d wrote on 2020-12-19, 07:29:As I mentioned earlier, there is a seller on eBay that is selling some Atom D525 based development boards that have PCI and ISA. […]
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ragefury32 wrote on 2020-12-19, 06:40:
LightStruk wrote on 2020-12-18, 16:29:
For anyone rooting for the Vortex86 EX2 option, I'm made contact with DMP and we're sending emails back and forth. One interesting new piece of information - the Master core of the EX2 can be configured to speak PCI or ISA, but not both at the same time. It's also unclear whether I could get PC/PCI signals (REQ, GNT, and SERIRQ) from the "Crossbar." It could mean that using the EX2 would force using an ISA sound chip like the CMI8330 or the YMF71x and a PCI-Express graphics chip, since PCI wouldn't be available! At that point, it's an open question whether the available PCI-E chips are even able to do the various VGA / SVGA / VBE modes required for this project - they would need to be tested.
Wouldn't it be easier to use an Atom SoC (Diamondville/Pineview) setup, then? The CPU cores can do EIST (enchanced speedstep) for more precise throttles, the Intel GMA950/3150 should be okay for DOS retrogaming (need more actual user experience write-ups and benchmarks here, though. I've heard "opinions" that are either overwhelming positive or negative but nothing backed by actual writeups and benchmarks), the ICH7m /Tiger Point PCH should do PCIe, PCI (YMF7x4 will be fine here), and LPC (which can probably do ISA with a suitable bridge chip) . It's also not that difficult to get your hands on an old-school Atom board inexpensively to prototype it out.
As I mentioned earlier, there is a seller on eBay that is selling some Atom D525 based development boards that have PCI and ISA. I looked stuff up before ordering one and found that there was an SBC made with the same SoC that said it supported ISA DMA.
I just received my board yesterday but have not had a chance to play with it though I did take a look at it and saw that it has an ITE8888 PCI-ISA bridge chip so my hopes are high that it has ISA DMA support.
Thing is, these Atom chips are no longer in production which is why the Vortex86 stuff is more desirable for a new build.
Edit. The D series Pineview do not support Enhanced Speedstep according to Intel.
Yeah well, the D-series Diamondville/Pineviews might not do EIST, but the N-series does, and as far as I can tell, the N450s and the D510/520s are often sold by the same vendors at the same time, and there are excess net-tops, netbooks, mini-1U servers and industrial boards out there with either CPU just begging for takers.
As for the not-in-production angle, I can also say the same thing about all the YMF/OPL3 chips out there - they have long been out of production, superseded by AC97 and then HDA, and has been sitting in warehouses just looking for takers. The Atoms are at least 6-10 years younger, everyone and their mom probably has one in the attic ready for experimentation - in some cases all they need is a PCI slot, or something that can tap the LPC bus for an LPC-to-ISA setup. The real headache here is that there is no such thing as plug-n- play LPC - SMBIOS tables are supposed to know about every LPC device connected to the machine, and using an LPC-to-ISA bridge chip and tossing a bog standard ISA device onto it would require the BIOS to accept the info for inclusion.
As for the Vortex86 stuff, it might or might not work. It really depends on what you potentially consider to be essential in those projects. In my mind, good VGA support first, HDMI support next, deal with the audio, and then followed by input stuff. Most modern thin clients with HDMI output (like an HP t520) can potentially be shoehorned into being DOS PCs. They'll need some attention with video compatibility, CPU throttling support, something that can allow them to deal with old school/legacy audio support (no idea if they have PCI or require something LPC/ISA), and they’ll need legacy keyboard/mouse support enabled to support modern wireless input methods.
I would say that the intricacies of EX2 master/slave setup isn't that important for now - it's the nuts and bolts of getting DOS games to work well on the platform that should get some attention - the slave side of the EX2 is really just an EX. The "normal" EX is out for the past 5 years, readily available on the 86Duino, and there are ample evidence that the Vortex86 VGA card (the one that runs off the PCIe bus using a bridge chip) sold by D&MP and attached to the 86Duino One works just fine for VGA and EGA.
https://www.youtube.com/watch?v=UAyxTVKtKek
There are also videos of it running Q2Dos and Doom just fine - Q2Dos even works with the HDA onboard sound.
https://www.youtube.com/watch?v=gTknwah3xy8
The Vortex86 VGA likely use the old SiS 550 2D core, which D&MP inherited when they bought the original Rise mp6 design from SiS in 2001 - it’s basically the 2D display engine from the SiS Mirage series. It’s not that hard to ask the vendor for the XP driver for the Vortex86 VGA - a single look at the inf file will tell you all you need to know (PCI ID for instance). You can probably find an old thin client with the SiS 550 GPU onboard cheaply for compatibility testing (Gona's charts doesn't have that one), and some with PCI onboard works just fine with soundcards - my 15 dollar Teco TR3230F with the SiS550 works fine with a YMF724, and I am pretty sure there is someone out there selling Neoware CA5s.
The EX and the EX2 both uses some type of I/O virtualization with a crossbar selection setup, and the EX has an abbreviated ISA (xISA) that allow IRQs and DMA channels, and someone in their forum even speculated as to using a combination of the 86Duino One, a Vortex86 VGA and xISA to make an old DOS gaming appliance roughly 5 years ago. You don’t really need to shoehorn a PCI video card in there.
http://www.86duino.com/?page_id=85/project-gu … ter-with-ms-dos
That approach is likely workable as long as someone puts the time and effort into it. A compatible breakout board with an old YMF719 or ES1869 for the 86duino would be good. Use a Vortex86 VGA chip with a VGA to HDMI / LVDS to HDMI adapter (with audio passed in from a converter board), and it'll probably do it. Supporting modern network stacks and bluetooth for handling gamepad or keyboard/mouse input, that might be a pain - I guess that's where the master/slave nature of the EX2 can help. The master can run Linux and deal with the housekeeping (bluetooth + Wifi on USB2?), and then pass keystrokes and mouse x/y locations to the slave running on DOS. Whether it works well enough for every requirement you might have or not, that's the other question. I don't think there are throttling methods supporting the Rise MP6 or its Vortex86 derivatives, but that’s for dealing with edge cases.
If I am engineering something like this, each DOS game will have its own small DOS-only running environment - its own game files (probably a subfolder in the game repo sitting on an SD card), its own save states, and its own set of virtual peripherals and environments (i.e. CPU speed, which peripherals are attached, what video modes are used, the setup as derived from config.sys/autoexec.bat, what I term to be the "secret sauce"), all well defined. The Linux instance running on the master core will handle actual peripherals, setup the DOS environment on the slave core, launch DOS with the parameters set, perform I/O operations for the slave, and then send the VGA output from the slave to the HDMI port. Provided that you have a well packaged repository of "secret sauce" to make each and every game work as well as you can on the slave, it can potentially be a very neat way of doing a DOS game console. Every game pre-packaged, with good config.sys/autoexec.bat settings, input mapped correctly, no need for multi-config menus, and the settings from one game not interfering with another.
Of course, my concern about using Vortex86 is that it's not really well supported outside of the firms owned by D&MP (ICop and etc), and if you want a full featured eval board you are still talking to the same people...not much opportunity to have a 3rd party fight for your business and get the pricing down en-masse. But as of now, not that important.
