- Extended memory (Wikipedia)
In DOS memory management, extended memory refers to memory above the first megabyte (2^20 bytes) of address space in an IBM PC or compatible with an 80286 or later processor. The term is mainly used under the DOS and Windows operating systems. DOS programs, running in real mode or virtual x86 mode, cannot directly access this memory, but are able to do so through an application programming interface called the Extended Memory Specification (XMS). This API is implemented by a driver (such as HIMEM.SYS) or the operating system, which takes care of memory management and copying memory between conventional and extended memory, by temporarily switching the processor into protected mode. In this context, the term “extended memory” may refer to either the whole of the extended memory or only the portion available through this API.
- Die photos and analysis of the revolutionary 8008 microprocessor, 45 years old (righto.com)
Intel’s groundbreaking 8008 microprocessor was first produced 45 years ago. This chip, Intel’s first 8-bit microprocessor, is the ancestor of the x86 processor family that you may be using right now. I couldn’t find good die photos of the 8008, so I opened one up and took some detailed photographs. These new die photos are in this article, along with a discussion of the 8008’s internal design.
