VOGONS


Reply 280 of 283, by BitWrangler

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Heh, I might manage up to E1:M6 in text mode, ('coz I know those well enough) but after that would struggle. The question is, is it better than the aalib doom. 🤣

(Though the real competition looks like this one using libaca with SDL ports... https://vimeo.com/139774508 )

2017: Basement full of ancient PC stuff, starting to go through it. 2021: Still starting, heh, many setbacks. So what's this BitWrangler guy's deal ??? >>> Taming the pile, specs to target?

Reply 281 of 283, by appiah4

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I'm having strange centering issues with a CL-GD5428 when using UniVBE, the screen is shifted to the right. Any ideas on how to fix that?

Retronautics: A digital gallery of my retro computers, hardware and projects.

Reply 282 of 283, by ViTi95

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appiah4 wrote on 2021-07-20, 21:53:

I'm having strange centering issues with a CL-GD5428 when using UniVBE, the screen is shifted to the right. Any ideas on how to fix that?

Same happens to mine, I usually fix it by adjusting the monitor.

BTW i'm adding a new mode with vertical monitor support, similar to TOOM (Tate Doom, featured in the LGR youtube channel https://youtu.be/V74eiGAbvDk). For now it renders on a backbuffer and then transposes and scales the frames to a VGA planar mode (320x400). The aspect ratio will be wrong, but this way is much easier to implement. If this results to be very slow, i'll do the same but without the scaling process on a 320x350 resolution, leaving black bars on the borders.

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Reply 283 of 283, by rasz_pl

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ViTi95 wrote on 2021-07-20, 17:23:

Edit: Do exist any ISA video card that supports LFB? The only card I have that is supposed to support it is a Cirrus Logic GD-5429, but UniVBE doesn't enable it at all (even with less than 16Mb of RAM). The same motherboard works fine with a GD-5426 and LFB enabled. Maybe someone here can try this new mode with a compatible ISA one.

dug out my old comments answering similar question:
"afaik only ISA Tseng ET4000 and ATI Mach64 supported LFB, with ATI being only one allowing mapping more than 1MB at once. ISA is limited to 24 bits of address space = up to 16MB, so new Bios option appeared in 386 and later motherboards called "Memory Hole At 15M-16M" to make room for 1MB of ISA card address space when computer has more than 15MB of ram. If you had 4MB ATI Mach64 and wanted it all mapped linearly you had to contend with 12MB ram max installed etc"

"Bios companion book covers VGA LFB ISA bios options https://books.google.com/books?id=69648Y1sOew … &q=LFB+ISA+card Page 270
ET4000: 3d4h index 36h (R/W): Video System Configuration 4 Linear addressing if set (4000) Video Memory is mapped as a 1 Meg block above 1MB. 5 ? Enable Tseng Addressing Mode (W32x) If set enables Memory Mapped registers. Three MMU areas exist.... 3CDh (R/W): Segment Select 6-7 Segment Configuration. 2 1M linear memory 3d4h index 30h (R/W): (W32x ?) bit 0-? Linear Frame Buffer Address in units of 4Mb"

"looking up VBE/AF documentation they only supported banked modes for ET4000/6000 chips"

tldr: there is a possibility ISA ATI Mach64 will support LBF