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+# About this Manual
+
+This manual describes the architecture and programming environment of a Vertex
+Mark I microprocessor. This manual applies to application programmers, operating
+system programmers and BIOS designers.
+
+## Notational Conventions
+
+This manual uses specific notation for data-structure formats, for symbolic
+representation and for hexadecimal and binary numbers. A review of this notation
+makes the manual easier to read.
+
+### Bit and Byte Order
+
+In illustrations of data structures in memory, smaller addresses appear toward
+the bottom of the figure; addresses increase toward the top. Bit positions are
+numbered from right to left. The numerical value of a set bit is two raised to
+the power of the bit position. Vertex processors are "little endian" machines;
+this means the bytes of a word are numbered starting from the least significant
+byte. Figure 1.1 illustrates these conventions.
+
+### Reserved Bits
+
+In many register and memory layout descriptions, certain bits are marked as
+**reserved**. When bits are marked as reserved, it is essential for
+compatibility with future processors that software treat these bits as having
+a future, but unknown, use. These bits should be treated as, not only undefined,
+but unpredictable.
+
+### Instruction Operands
+
+When instructions are represented symbolically, a subset of the Vertex-32
+assembly language is used. In this subset, an instruction has the following
+format:
+
+```
+label: mnemonic argument1, argument2, argument3
+```
+
+where:
+
+* A **label** is an identifier which is followed by a colon
+* A **mnemonic** is a reserved name for an instruction opcode
+* The operands *argument1*, *argument2* and *argument3* are optional. There may
+  be from zero to three operands, depending on the opcode.
+
+When three operands are present in an arithmetic or logical operation, the first
+operand is the destination register and the remaining two are either source
+registers or immediate values. For example:
+
+```
+load: ADDI AX, BX, subtotal
+```
+
+In this example, `ADDI` is the mnemonic identifier of an opcode, `AX` is the
+destination operand, and `BX` and `subtotal` are the source operands.
+
+### Hexadecimal and Binary Numbers
+
+Base 16 (hexadecimal) numbers are represented by a '0x' followed by a string of
+hexadecimal digits. A hexadecimal digit is a character from '0' to '9' and 'A'
+to 'F'. Base 2 (binary) numbers are represented by a string of 1s and 0s,
+sometimes preceded by '0b' (for example, 0b1010). The '0b' designation is only
+used in situations in which confusion about a number's base may arise.
+
+### Exceptions
+
+An exception is an event that typically occurs when an instruction causes an
+error. For example, an attempt to divide by zero generates a divide-by-zero
+exception. All exceptions provide either an error code or 0, indicating no
+error. An error code reports additional information about the error. For
+example, a page fault would provide a fault code indicating what caused the page
+fault.