Taking an ISA Graphics Card to the Max! ISA Bus Overclocking #isadoom25fps

The 16-bit ISA bus was becoming a very serious bottleneck for PC graphics in the early to mid nineties. 3D games like Doom really didn’t run well unless a VESA Local Bus or PCI graphics card was used. There were some ways to get some extra performance though – by overclocking the ISA bus! Today I’ll be pushing the ISA bus to the max to see just how quick games like Doom can run. #isadoom25fps Doom realtic to frames per second conversion (applicable for demo3 only): FPS = 74690 / ticks CPU Galaxy’s YouTube Channel: @CPUGalaxy CPU Galaxy’s Website: Phil’s DOS Benchmark Pack: Twitter: Mastodon: @vswitchzero My Blog: 00:00 Introduction 01:03 A Bit of History 02:39 The Doom 25FPS Challenge 04:27 Strategy 05:38 Hardware Setup 08:29 BIOS Woes 11:17 ISA Bus Overclocking 12:28 System Tuning 13:04 Taking the ISA Bus to the Max! 14:58 Result Summary 16:12 Pure ISA Testing 18:26 Other ISA Cards at 25MHz 19:30 Conclusion A big thanks to @chaslinux and Lee from Nova Scotia for donating parts used in this video today. Much appreciated!