I just got a hold of a PC CRT monitor with a native resolution of 1600X1200. The lowest resolution that it supports is 640x480. Would this monitor be good for old DOS games like the Lucasarts and Sierra adventure games from the early 90's to mid 90s or is the resolution too high? Should I get another monitor with lower resolution dedicated for those games and use my current monitor for windows 98/XP gaming?
A VGA card "upscales" all 320x200 games to 640x400. Your monitor surely supports 640x350 and 640x400. All standard analog PC monitors do. If you have a classic Award BIOS, the boot screen with the energy star logo is displayed in 640x350, and the text mode VGA screen before Windows starts is 720x400. The windows start logo is 320x200 (double-scanned to 400 lines), like all the good old games.
So your monitor is perfectly able to display all EGA and VGA games, but the beam might be so fine that the image consists of separate horizontal lines seperated by black lines. This is an effect known as "scan-lines", and while it is often seen as feature for period-correct CGA display (which just had 200 lines), it is usually seen as misfeature for period-correct EGA/VGA display. If your monitor offers "moire reduction" in the menu, it might do that by slightly defocussing the beam, which reduces sharpness, but at the same time also reduces the scanline effect.
I see. Let's say for sake of argument I have another monitor with a lowest supported resolution of 1600x1200. Can I assume that this monitor would NOT be a good candidate for early 90s to mid 90's DOS adventure games?
A CRT can display any arbitrary resolution so long as the pixel clock falls in a supported range. Which is huge. 320x200@70hz won't work but 320x200@140hz will. In DOS lower resolutions are scan doubled to higher ones to be compatible with 31khz displays.
Your graphics card will limit what you can but your monitor won't.
LCDs are entirely different. They have a fixed number of pixels and often a fixed refresh rate. You are relying on their firmware to know what to do with each signal, but no matter what they have to be digitally sampled.
mothergoose729 wrote on 2021-03-25, 20:46:A CRT can display any arbitrary resolution so long as the pixel clock falls in a supported range. Which is huge.
You probably mean "so long as the horizontal frequency falls in a supported range". This range is huge on newish CRTs, but this didn't use to be that way. Early monitors had TV timing, with an working horizontal frequency range of around 15.2 - 16.0 kHz. They were specified for one single horizontal frequency. The same is true for the original IBM monochrome monitor (to go along with the MDA card), which is specified for 18.4kHz. Rumor has it that this monitor (as it doesn't have its own oscillator, but entirely depends on the video signal) is indeed destructible by an invalid horizontal timing. EGA monitors allowed two different frequencies, 15.6kHz (for the TV-compatible CGA timing) or 21kHz, but they were specified as dual scan: Either 15.6 or 21, but not the whole range in-between. VGA monitors were single-frequency again, this time 31.5 kHz.
Only after VGA was an established standard, and high-res monitors started to get into the PC market, the horizontal frequency range started to grow. The 31.5kHz VGA rate was a requirement for compatibility with the PC boot process. Monitors started to be specified for ranges now, 31.5-35.5kHz for 640x480 @ 60Hz and 1024x786 @ 87Hz interlaced, possibly also supporting 800x600 @ 56Hz. The next step up supported up to 38kHz and included 800x600 @ 60Hz. Then, the next step up is 31.5kHz - 48kHz, which adds 1024x786 @ 60Hz non-interlaced. Whether 1024x786 is easier on the eyes as 87 interlaced or 60 non-interlaced depends a lot on the specific monitor. With 31.5kHz - 56kHz, you obtained 1024x786 @ 70 Hz, which was kind-of flicker-free. The higher the supported horizontal frequency, the more expensive the CRT got. Things went up from there (and prices down), and around 2000, you could find 31.5kHz - 98 kHz sync rate monitors even in german supermarkets as special offers.
Also, vertical frequency needs to be in range, but this is much less of a problem. Stanadard VGA has 60 and 70 Hz (VGA monitors usually support the whole range), and most more modern monitors go down to 56 Hz for the early 800x600 timing, and go up to 87 Hz for the interlaced timing at least, so 55-90 is given for most monitors. Especially for 3D rendering with shutter glasses, rates up to 160Hz were supported. Supporting a bigger vertical range is quite easy for the electronics, so vertical frequency range was usually not something you had to spend money on.
slai50 wrote on 2021-03-25, 20:41:I see. Let's say for sake of argument I have another monitor with a lowest supported resolution of 1600x1200. Can I assume that this monitor would NOT be a good candidate for early 90s to mid 90's DOS adventure games?
This assumption is valid. Such monitors exist for specialized CAD workstations of the early 90s. They are generally not DOS compatible, and do not work with standard VGA cards. On the other hand: If a monitor has a standard VGA plug, you can safely assume that it supports all DOS games, the only (perceived) problem being scanlines in the lower resolutions.
CRTs have tolerance in all directions. The pixel clock is easier to talk about, because people usually aren't trying to run software at below VGA resolutions and refresh rates. The OP has a SVGA capable monitor, pre SVGA display types aren't particularly relevant.
The short of it is, if you have an older graphics card it will handle DOS and windows 98 fine with any CRT display. Most monitors can do pretty high resolutions like 1600x1200 or even higher, depending on how high of a pixel clock they are willing to tolerate. Note that the number of phosporus in the display is what it is, so higher resolutions doesn't always mean you get more detail.
On an LCD display you are likely to get a picture but it probably won't look the way you expect. Scaling and frame pacing issues are to be expected.
I recently completed a project where I emulated DOS games with DOSBox at native DOS resolutions using a more modern GPU, if you care to do that.
The Quest for Pixel Perfect DOS Emulation
Another fun thing you can do is emulated old 8 bit and 16 bit consoles at their native resolutions and a higher refresh rate. You get a bold scanline effect and a really clean picture which some people liken to high end professional monitors.
I've read that 320x200 resolution games look best on a smaller(15 or 17in) shadow mask CRT, how true is this? I currently own a 21 inch diamond pro 2020u. Would a smaller monitor really look that much better for 320x200 games?
slai50 wrote on 2021-03-28, 14:14:I've read that 320x200 resolution games look best on a smaller(15 or 17in) shadow mask CRT, how true is this? I currently own a 21 inch diamond pro 2020u. Would a smaller monitor really look that much better for 320x200 games?
This is similar to the argument games look best on a CRT TV set.
A clear big version of a low res image looks fine in my mind but the artistry looks better on a small screen to most because your eyes blend it together better with the artifacts of the shadow mask being apart of the intended image.
