To have this choice is sometimes useful, since ISOLINUX is vulnerable to BIOS bugs. For that reason, it is handy to be able to boot using SYSLINUX. This mostly affects computers built before about 1999, and, in fact, for modern computers the "no emulation" mode is generally the more reliable method. Newer ISOLINUX versions support creation of so-called "hybrid ISO" images, that put both the "El Torito" boot record of the compact discs and the master boot record of hard disks into an ISO image. This hybrid image could then be written to both a compact disc or a USB flash drive.