Re: Analog composite video output on PCs - how do 70 Hz modes even work?

Posted on 2020-07-30, 15:10

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

Both, CGA and EGA, are strictly 60Hz, only¹. 70Hz text modes are a VGA thing. The text mode they output to a composite screen typically uses 80x25 8x8 pixel character cells, which results in an effective resolution of 640x200 pixels, which in turn means that no interlacing is required. However, my …

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Re: Say "Hi!" to the Renovation SSI-2001!

Posted on 2020-07-30, 13:10

by

by Benedikt

in Marvin \ Sound

in Marvin \ Sound

I wonder if we could get a dummy IC package... :) If a dummy is all you need, you could take any random 28-pin chip, drill the die out from below and plug it in. ... Or look for the worst-rated Aliexpress shop for SID chips and buy a piece of plastic with legs from them. hehe looks funny, but will …

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Re: Say "Hi!" to the Renovation SSI-2001!

Posted on 2020-07-29, 18:33

by

by Benedikt

in Marvin \ Sound

in Marvin \ Sound

How do you like this sticker design? sticker.jpg The purpose of the sticker is to cover up the µC in the SID-less configuration. The design is loosely inspired by Eastern Bloc white(ish) CERDIP packages that were used for Z80 clones and such. So why not use it for a SID clone? I picked the white …

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Re: CGA2SCART development thread

Posted on 2020-07-28, 12:58

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

I tried my SCART2HDMI converter today. As you can see the left side av the screen is capped. I guess this is a problem with horizontal alignment? Anyone that has an idea how to fix this? I can only guess, here, but maybe it has a menu-selectable auto-adjust feature like many screens and crops the …

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Re: CGA2SCART development thread

Posted on 2020-07-28, 10:41

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

No different signals, but a different resolution which the output device needs to support - 480 scanlines for NTSC, 576 for PAL. That's not technically related to PAL or NTSC, but whether it is based on system M (525 lines toltal) or one of the others (625 lines total). Any TV set should support …

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Re: CGA2SCART development thread

Posted on 2020-07-28, 09:20

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

Maybe I'm a bit slow here, but given that SCART supports multiple signal types, which one/ones is this supporting? CGA RGB -> SCART RGB? CGA composite -> SCART composite? Both? Or something else? And what about NTSC vs PAL? Whatever it is exactly, it's looking good though :) Its RGBi (CGA RGB) to …

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Re: CGA2SCART development thread

Posted on 2020-07-27, 20:03

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

I think it's interesting that your flat panel TV appears to blend adjacent colors in the 640x200 modes. Maybe it uses an NTSC notch filter for all kinds of analog input and not just for composite signals.

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Re: 6€ MCE2VGA replacement - CGA/EGA/HGC capture with logic analyzer

Posted on 2020-07-27, 08:39

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

Still no aspect ratio correction available ? It'd be nice to have that :D Also does it still need a beefy CPU or can a raspberry pi run it ? Using it on a Raspberry Pi would be quite silly, because a Raspberry Pi has plenty of GPIOs and several PLL clock generators. It wouldn't surprise me if it …

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Re: Say "Hi!" to the Renovation SSI-2001!

Posted on 2020-07-26, 10:53

by

by Benedikt

in Marvin \ Sound

in Marvin \ Sound

I have added some high-res product photos to the git repo. Here's a preview: Filename product_photo_front_small.jpg File size 78.35 KiB Views 1038 views

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Re: Which Sierra games can use the PC1512.DRV so they have 16colors with an Amstrad 1512 system?

Posted on 2020-07-26, 09:37

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

Since you're testing quite a few games now... How would you describe the speed of the VDU mode? Can it compete with the MCGA mode in an otherwise similarly equipped machine?

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Re: 6€ MCE2VGA replacement - CGA/EGA/HGC capture with logic analyzer

Posted on 2020-07-25, 17:36

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

What I will try next: The Analyzer is easy to open and you see a single crystal: 24.000 MHz for the max sample frequency. I will replace it with a socket to see how it behaves with other crystals. 16.257 MHz would be great. Dont know if this works or if it interferes with the USB-transfer. There is …

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Re: Planet X3 by 8-Bit Guy nearing completion! New teaser & music

Posted on 2020-07-25, 10:31

by

by Benedikt

in Milliways

in Milliways

Or a real M24, so I could also test 640x200x16 in all its glory. ^^ Provided that you get your hands on one of those ultra rare expansion boards, as well. I believe MobyGamer managed to snatch one of them, so there would be a chance to test it on real hardware. I, personally, have never even seen …

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Re: Planet X3 by 8-Bit Guy nearing completion! New teaser & music

Posted on 2020-07-23, 15:38

by

by Benedikt

in Milliways

in Milliways

So except for exotic video modes, such as Amstrad/Schneider PC1512, Olivetti M24, BBC Master 512, Sanyo MBC 555 , IBM PGC , 8514/A , TIGA and Mindset graphics the game virtually covers all types of old video hardware. I don't know - the Amstrad PC1512 was much more common and less exotic than …

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Re: Planet X3 by 8-Bit Guy nearing completion! New teaser & music

Posted on 2020-07-22, 11:26

by

by Benedikt

in Milliways

in Milliways

That makes me wonder, if there is a non-standard floppy format with more capacity that could be used. XDF is supported by IBM DOS 7, but not DOS 2.11 or whatever the Tandy 1000 uses. https://en.m.wikipedia.org/wiki/IBM_Extended_Density_Format XDF appears to extend High Density disk formats, only. …

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Re: Planet X3 by 8-Bit Guy nearing completion! New teaser & music

Posted on 2020-07-21, 20:40

by

by Benedikt

in Milliways

in Milliways

There's no exact 1:1 mapping, because the Tandy artwork has apparently been derived from the CGA composite artwork, manually. But with a bit of luck a 1:1 mapping might not look significantly worse. I'd rather derive the composite artwork from the Tandy artwork, because the four different color …

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Re: Planet X3 by 8-Bit Guy nearing completion! New teaser & music

Posted on 2020-07-21, 17:46

by

by Benedikt

in Milliways

in Milliways

My impression is that sourcing a soundtrack for the SID would not even be the biggest problem. I'm sure that someone out there would happily take care of a manual conversion, should the need arise. The biggest obstacle, however, would remain: It's disk space. There's the General MIDI soundtrack, the …

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Re: Planet X3 by 8-Bit Guy nearing completion! New teaser & music

Posted on 2020-07-21, 11:46

by

by Benedikt

in Milliways

in Milliways

That's wonderful news. Its amazing so many people contributing on Planet X3. I'm happy to have made a small contribution, fixing that INT29h bug. For the sound department i would love for Innovation SSI support. But, much more difficult than GM and MT-32 as those are composed already. In any case …

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Re: Planet X3 by 8-Bit Guy nearing completion! New teaser & music

Posted on 2020-07-20, 20:24

by

by Benedikt

in Milliways

in Milliways

Everyone has probably seen this but, this genius "Benedikt Freisen" added a bunch of video modes: (https://www.youtube.com/watch?v=wCx32lrBSNQ&feature=youtu.be&t=2107) Plantronics Colorplus 320x200x16, 640x200x4,620x200,16 CGA Monochrome 2 Color EGA Hercules If the MT32 is not that much code, and …

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Re: 6€ MCE2VGA replacement - CGA/EGA/HGC capture with logic analyzer

Posted on 2020-07-19, 14:24

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

I just had another idea, namely for a hardware-assisted solution. If we add an oscillator matching the pixel clock, an edge-triggered flip-flop and an xor-gate, we could invert the polarity of the sampling clock depending on whether the oscillator output is high or low during the rising edge of the …

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Re: 6€ MCE2VGA replacement - CGA/EGA/HGC capture with logic analyzer

Posted on 2020-07-19, 08:33

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

Thats the surprise. I tested 2 different HGC cards with a 16.00MHz OSC on it. But there are some jitters anyway. They are not static but appear on a different line on each frame. This shouldnt be. I wouldn't necessarily call that a surprise, but rather the expected behavior. In the end of the day, …

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