Monthly Archives: October 2022

Does (E)IP Wrap Around in 16-bit Segments?

The 8086/8088 is a 16-bit processor and offsets within a 64K segment always wrap around. If a one-byte instruction at offset FFFFh is executed on an 8086, execution will continue at offset 0. This is simply a consequence of the … Continue reading

Posted in 386, 8086/8088, Intel, x86 | 9 Comments

PC Disk Sector Sizes and Booting

Everyone knows that the IBM PC established 512-byte sectors on floppies and hard disks as the standard, which survived for several decades until the advent of “native” 4K-sector drives. Of course what “everyone knows” is not necessarily the whole story. … Continue reading

Posted in BIOS, DOS, IBM, PC history, Storage | 10 Comments

IBM AIX for IA64 (Itanium) aka Project Monterey Runs Again!

(This is a guest post by Antoni Sawicki aka Tenox) Project Monterey was an attempt to unify the fragmented Unix market of the 90s in to a single, cross vendor Unix OS that would run on the upcoming Intel Itanium … Continue reading

Posted in IBM, Intel, SCO, UNIX | Tagged , , , , , , , | 10 Comments