IBM AT BIOS Information ======================= The files in this directory contain the last known BIOS update for the IBM 5170 PC/AT. This BIOS revision fixes compatibility with third-party disk controllers. Earlier IBM BIOSes will cause random data corruption when using third-party disk controllers. These files were generated from EPROMs pulled from an IBM 7532 Industrial AT. We still support these machines and have been running XT-IDEs with them in 24/7 production operation for over a decade with zero corruption issues. The IBM 7532s we service all have Type 3 motherboards and carry this same version of the BIOS. These EPROMs carried a copyright date of 1987. With this version of the PC/AT BIOS, you'll also still have IBM ROM BASIC. * 61X9265.HEX goes in U47 * 61X9266.HEX goes in U27 Both files are Intel HEX format. You'll need to make sure your EPROMs are sufficiently fast for your PC/AT. Commonly available 150 nS EPROMs ensure this regardless of the motherboard revision and clock speed. Dumped by Glitch Works http://www.glitchwrks.com/