I assume 36 Mhz clock is needed for the classic Super VGA (800x600 16c).

http://tinyvga.com/vga-timing

With merely 256 KB of video ram, two SVGA resolutions are possible:

- 640x400 @256 (VBE mode 100h)
- 800x600 @16c (VBE mode 102h, 6Ah)

The VBE BIOS isn't in ROM, however.
It was a DOS TSR stored on the driver diskette, along with the MODE utility.

The Paradise and Western Digital cards can be used with Windows 2.03 and 3.x quite easily.
Wonderland by Magnetic Scrolls supports them, too.

PCem and various DOSBox releases emulate the Paradise PVGA1A.

There Windows drivers have another good feature.
They're 80286 compatible, partially at least.

There's a Windows 2.x driver package at toastytech.com, which includes a Paradise driver.

640x400 is extra fine, because the 400 lines are more compatible with Windows 1.x applications written with an EGA screen in mind.
That's why Windows 2.11 (afaik) had lost the original 640x480 16c driver that was available in Windows 2.03.

Note: The old Super VGA 800x600 driver of Windows 3.1x supports the PVGA1A/B, WD90Cxx chips. Ideal for testing, imho.
The 640x480 @256 version of Windows for Workgroups 3.11 doesn't, afaik (what if video RAM is 512 KB?)

All versions of the Paradise PVGA1A support 512 KB, as far as I know.
Early SVGA cards can be upgraded by mounting a second set atop of the existing RAM chips.
That piggy-back method merely requires the address lines to be passed through (in series, not parallel) the new RAM chips.

PS: Please check the configuration of the DIP switch, also.
Super VGA maybe requires Multisync or NEC setting.

Jo22 wrote on 2022-12-13, 03:49:

I assume 36 Mhz clock is needed for the classic Super VGA (800x600 16c). […]
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I assume 36 Mhz clock is needed for the classic Super VGA (800x600 16c).

http://tinyvga.com/vga-timing

With merely 256 KB of video ram, two SVGA resolutions are possible:

- 640x400 @256 (VBE mode 100h)
- 800x600 @16c (VBE mode 102h, 6Ah)

The VBE BIOS isn't in ROM, however.
It was a DOS TSR stored on the driver diskette, along with the MODE utility.

The Paradise and Western Digital cards can be used with Windows 2.03 and 3.x quite easily.
Wonderland by Magnetic Scrolls supports them, too.

PCem and various DOSBox releases emulate the Paradise PVGA1A.

There Windows drivers have another good feature.
They're 80286 compatible, partially at least.

There's a Windows 2.x driver package at toastytech.com, which includes a Paradise driver.

640x400 is extra fine, because the 400 lines are more compatible with Windows 1.x applications written with an EGA screen in mind.
That's why Windows 2.11 (afaik) had lost the original 640x480 16c driver that was available in Windows 2.03.

Note: The old Super VGA 800x600 driver of Windows 3.1x supports the PVGA1A/B, WD90Cxx chips. Ideal for testing, imho.
The 640x480 @256 version of Windows for Workgroups 3.11 doesn't, afaik (what if video RAM is 512 KB?)

All versions of the Paradise PVGA1A support 512 KB, as far as I know.
Early SVGA cards can be upgraded by mounting a second set atop of the existing RAM chips.
That piggy-back method merely requires the address lines to be passed through (in series, not parallel) the new RAM chips.

PS: Please check the configuration of the DIP switch, also.
Super VGA maybe requires Multisync or NEC setting.

Many thanks for this wealth of info!

Jumpers and DIP switches are properly set.
Using the WHATVGA utility, both modes work (either via detection of the "native" chipset or via UNIVBE).
Can't see any difference when JP1 is open or closed though (appart from a momentary size auto-calibration of the monitor after the JP1 status is changed).

Best regards!