Re: EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2021-07-08, 19:00

by

by root42

in Marvin \ Video

in Marvin \ Video

So I replaced the 300 Ohms with 270 Ohms and the artifacts were severly reduced. However it is still not good. Monkey Island 2 has a few noise columns, while Windows has lots of stray pixels. This is still far from usable. I think I will have to chalk this project up to experience... Is there any …

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Re: Newly made Gravis Ultrasound compatible cards ... what's the degree of interest?

Posted on 2021-07-03, 07:58

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by root42

in Marvin \ Sound

in Marvin \ Sound

Didn't some russian guy already made GUSAR that was basically an IW card initially cloning Argus and then moved to their own design? Not a PCB design that he's shared and the PCBs are no longer available to purchase :( Indeed. I have one, which Shock repaired for me, because I botched the soldering …

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Re: Vogons Video Announcement Thread

Posted on 2021-06-30, 06:57

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by root42

in Milliways

in Milliways

Hey long time no vid good to see you back! Yes, quite a lot of other things on my hands, plus the ET4000W32i isn't working yet. But I will pick up speed in a couple of weeks when things have settled down again. :) Plus I only announce MS DOS / PC related content here, but there were some non-PC …

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Re: Vogons Video Announcement Thread

Posted on 2021-06-29, 16:54

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by root42

in Milliways

in Milliways

Let's Code MS DOS 0x1D: Melting the VGA Screen One of the effects that is easy to do on machines like the C64 or Amiga is the „melting screen“. In theory you can do such things just by copying lots of pixels in video memory. However the VGA is rather slow for doing that. So what we will do instead …

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Re: EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2021-06-26, 19:18

by

by root42

in Marvin \ Video

in Marvin \ Video

That explanation sounds very reasonable. Waiting for my desoldering station to arrive so I can swap out the resistors... I guess I will have to acquire more ICs and wait for the next board revision as well. 😀

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Re: EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2021-06-26, 04:57

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by root42

in Marvin \ Video

in Marvin \ Video

@ALEKS: I measured the signal on the top resistor array. It was 10 MHz, so I guess my 200MHz scope should be able to show it in at least somewhat reasonable detail. I think the signal looks a bit wavy with a pretty slow rising signal, almost sawtooth like. And there is this small bump at the bottom. …

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Re: EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2021-06-23, 08:25

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by root42

in Marvin \ Video

in Marvin \ Video

And how much time does assembly take - roughly, and after one or two successful builds for practice? I still don't think this sounds awful, given that it would provide one of the best possible graphics solutions for ISA-class machines with none of the usual issues with such old hardware. If …

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Re: EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2021-06-23, 08:09

by

by root42

in Marvin \ Video

in Marvin \ Video

The biggest costs are the ET4000W32i chip (I paid 20€ per piece after customs from questcomp), the RAM and the RAMDAC. PCBs are less than 10€ at JLC. At the moment a full kit is roughly 100€. If we can get the ET4000 chips for cheaper that would help. But I doubt we get it lower than 80-90€ BOM cost …

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Re: EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2021-06-22, 17:52

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by root42

in Marvin \ Video

in Marvin \ Video

pan069 wrote on 2021-06-20, 20:47: root42 wrote on 2021-06-20, 20:00: More screenshots, showing okay CGA screens and broken VGA and SVGA stuff. Problem with memory? According to Aleks it's a problem with the RAS/CAS resistor networks. Touching them from the solderside makes the problem much worse. …

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Re: EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2021-06-20, 20:00

by

by root42

in Marvin \ Video

in Marvin \ Video

More screenshots, showing okay CGA screens and broken VGA and SVGA stuff.

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Re: EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2021-06-20, 19:58

by

by root42

in Marvin \ Video

in Marvin \ Video

My card is finished and it works in text modes and CGA color and B&W modes. It fails in EGA, VGA and SVGA modes. Also accelerated Win3.1 is broken. I have attached a bunch of screenshot.

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Re: EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2021-06-15, 08:12

by

by root42

in Marvin \ Video

in Marvin \ Video

Thanks for the hints. We will see if it's the 330R resistors once my card is finished. If I have the same problem, I would suspect that 270R or 300R might improve the situation!

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Re: EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2021-06-15, 07:22

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by root42

in Marvin \ Video

in Marvin \ Video

A friend on the dosreloaded forum assembled his card and has some glitches. Any ideas what they are caused by? Is this a faulty RAM IC? Or are the RAS/CAS resistors still too low a value? EDIT: Or maybe a cold solder joint on RAM/ET4000? Filename C7340783-049C-4CE2-ABFA-EF4950FBFF67.jpeg File size …

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Re: GLX Player the only XT player ? Check Mod Master...

Posted on 2021-05-31, 15:28

by

by root42

in Marvin \ Sound

in Marvin \ Sound

FreddyV wrote on 2021-05-27, 18:54: Anyway, OPL3LPT does no sound for S3M and SAT Music, I still don't know why. Are there many S3Ms using the OPL? I think there was one sample file with Scream Tracker 3, but that's all I know of.

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Re: EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2021-05-31, 15:27

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by root42

in Marvin \ Video

in Marvin \ Video

ALEKS wrote on 2021-05-30, 16:40: Looks great already. Don't forget about increasing of RA2 and RA3 to reduce artifacts in certain old games. PS: What exactly do the RA2 and RA3 do? And are the artifacts merely visual (e.g. due to the RAMDAC getting wonky data) or are the actual RAM contents …

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Re: EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2021-05-31, 11:11

by

by root42

in Marvin \ Video

in Marvin \ Video

Looks great already. Don't forget about increasing of RA2 and RA3 to reduce artifacts in certain old games. Yes, I have all the parts here now, including the uprated RA2 and RA3. Currently divyying up the parts for the other dosreloaded members who took part in the order. Sometime in the next 2 …

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Re: EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2021-05-28, 18:03

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by root42

in Marvin \ Video

in Marvin \ Video

My PCBs came back with the RAM and GPU soldered. Looks pretty good! Will start soldering the rest in a couple of days.. Filename 54BC1349-3803-4E63-9F8D-4C2381963EFB.jpeg File size 1.57 MiB Views 1778 views

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Re: Vogons Video Announcement Thread

Posted on 2021-05-24, 18:03

by

by root42

in Milliways

in Milliways

About a year ago I acquired a very cheap Atari 2600 Jr. It had only RF output, so I can’t use it on my CM8833-II monitor. A composite mod was required. I decided this time around to get the deluxe mod from The Future Was 8bit and see if it’s worth the extra expense. For extra points, after opening …

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Re: GLX Player the only XT player ? Check Mod Master...

Posted on 2021-05-17, 19:28

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by root42

in Marvin \ Sound

in Marvin \ Sound

FreddyV wrote on 2021-05-17, 18:36: The TNDLPT does not use the same chip as the Tandy 1000, so some of the Lemmings sounds wrong. Yeah, same problem with Zak McKracken. I think the proper chip is so rare, I only saw it ONCE on eBay in the last years, and it was for a ridiculous price.

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Re: EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2021-05-17, 12:48

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by root42

in Marvin \ Video

in Marvin \ Video

ALEKS wrote on 2021-05-15, 09:31: But the interest remains in accelerating DOS commandline only text output. I am pretty sure the DIR command uses standard DOS interrupts for writing to the console output. You could probably make an accelerated command.com... With soft-scrolling maybe? 😀

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