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Glossary
Below is a list of commonly-referenced computing and programming terms found throughout the Better Bally Book:
B
BCD:
D
debounce:
dope vector:
“A data structure used to hold information about a data object, e.g. an array, especially its memory layout…The dope vector includes an identifier, a length, a parent address, and a next child address.”
Source: Dope vector
E
endian:
F
framebuffer:
“A framebuffer (frame buffer, or sometimes framestore) is a portion of RAM[1] containing a bitmap that is driven to a video display from a memory buffer containing a complete frame of data.”
Source: Framebuffer
H
high-order:
I
interrupt page address register (I): An 8-bit register that can be loaded with a page address of an interrupt service routine. During a mode 2 interrupt program, control will vector to this page address. (SC:29)
L
light pen:
low-order:
M
microcomputer: A logical machine that manipulates binary numbers (data) and processes this information by following an organized sequence of program steps referred to as instructions. (SC:21)
microprocessor: The single integrated circuit around which a microcomputer is constructed. The microprocessor is a device (e.g., the Z80); the microcomputer is a system (e.g., the Bally Arcade). (SC:22)
P
program counter (PC): Contains a 16-bit address in memory from which the current instruction will be fetched. Following execution of the instruction, the PC counter is either incremented, if the program is to proceed to the next byte in memory, or the present PC contents are replaced with a new value, if a jump or call instruction is to be executed. (SC:28)
R
reentrant:
“In computing, a computer program or subroutine is called reentrant if it can be interrupted in the middle of its execution and then safely called again (“re-entered”) before its previous invocations complete execution.”
Source: Reentrancy (computing)
register:
S
scratchpad:
semaphore:
“A variable or abstract data type used for controlling access, by multiple processes, to a common resource in a concurrent system such as a multiprogramming operating system. A trivial semaphore is a plain variable that is changed (for example, incremented or decremented, or toggled) depending on programmer-defined conditions. The variable is then used as a condition to control access to some system resource.”
Source: Semaphore (programming)
stack: A reserved area of several memory locations, the top of which is indicated by the contents of the stack pointer. Memory location are organized as a last-in, first-out file. By looking at particular entries in the stack, the central processor returns to a main program regardless of the depth of nested subroutines. (SC: 28-9)
