I used to use custom modelines to overclock CRT monitors.
Monitors had a spec, of course -- and it was easy-enough to stay within that spec. They were bandwidth-constrained, but as analog devices that bandwidth was always somewhat flexible.
So why have settle for 1024x768 at 75Hz that the book says will work, when that same 15" monitor would do 1360x1020 or more at a similar refresh rate and still have readable tiny text? Why not run a 19" monitor at 2130x1598?
"You can fit so many xterms in this baby!"
And why not shrink down the vertical blanking interval and front and back porches as far as possible before geometry got too bad, to maximize the number of pixels that could be pushed down the wire within a given bandwidth? And why not tweak the trimpots inside to put the monitor's front panel controls into a better range for this kind of service?
Fun times, those. The quality of the VGA cable made a substantial difference in smear when pushing things hard enough (literally bandwidth-throttled video), and getting a better DAC to drive the kit with (for even more literal bandwidth) was a primary motivation for periodically finding a better video card.
(No fires to report even after a decade and a half or so of these games. Sorry. I guess if any of this stuff ever caught on fire I'd have found a different approach.)
640x480 became 704x512. "You are going to hurt your eyes. 800x600 = 875x660, and 1024x768 = 1152x830. Never blew up a monitor, but never ran over scan without the real documentation.
Monitors had a spec, of course -- and it was easy-enough to stay within that spec. They were bandwidth-constrained, but as analog devices that bandwidth was always somewhat flexible.
So why have settle for 1024x768 at 75Hz that the book says will work, when that same 15" monitor would do 1360x1020 or more at a similar refresh rate and still have readable tiny text? Why not run a 19" monitor at 2130x1598?
"You can fit so many xterms in this baby!"
And why not shrink down the vertical blanking interval and front and back porches as far as possible before geometry got too bad, to maximize the number of pixels that could be pushed down the wire within a given bandwidth? And why not tweak the trimpots inside to put the monitor's front panel controls into a better range for this kind of service?
Fun times, those. The quality of the VGA cable made a substantial difference in smear when pushing things hard enough (literally bandwidth-throttled video), and getting a better DAC to drive the kit with (for even more literal bandwidth) was a primary motivation for periodically finding a better video card.
(No fires to report even after a decade and a half or so of these games. Sorry. I guess if any of this stuff ever caught on fire I'd have found a different approach.)