Extended Brookshear Machine emulator and assembler: showinstructions - File Exchange

Code covered by the BSD License

Highlights from
Extended Brookshear Machine emulator and assembler

Extended Brookshear Machine A...
Extended Brookshear Machine E...
bm(varargin) BM GUI for Brookshear Machine emulator
assembler(file) ASSEMBLER is an assembler for the extended Brookshear machine
bitmapDisplay(hObject) BITMAPDISPLAY displays low 128 bytes of memory as 32x32 bitmap
bits2strings(a, i, type) BITS2STRINGS returns strings for displaying memory contents
bmachine BMACHINE starts the emulator and assembler GUI
dble2f8(d) DBLE2F8 converts from double to Brookshear's 1-byte floating point
dble2int8(d) DBLE2INT8 converts double to 1-byte signed integer
decodeInstr(b1, b2) DECODEINSTR decodes a BM instruction
f82dble(f) F82DBLE converts Brookshear 1-byte float to double
instr2string(type, b1, b2) INSTR2STRING returns string representation of instruction
instr2string_ass(b1, b2) INSTR2STRING_ASS returns string representation of instruction
instr2string_desc(b1, b2) INSTR2STRING_DESC returns string representation of instruction
int82dble(i) INT82DBLE converts 1-byte signed integer to double
loadmem(machine, text) LOADMEM loads instructions from text into memory
memstrings(machine, rows, ins... MEMSTRINGS returns strings describing contents of memory as instructions
newbm NEWBM creates a new Brookshear machine
nibbles2byte(x, y) NIBBLES2BYTE converts two nibbles to a byte
oddaddr(pc, a) ODDADDR checks whether an address is at an odd offset from the pc
readtext(filename) READTEXT reads a file's text into a string
regstrings(machine) REGSTRINGS returns strings representing the current state of the registers
resetReg(machine) RESETREG resets registers
saveDisplay(hObject) SAVEDISPLAY saves the current display in a file
savemem(machine, file, instty... SAVEMEM saves the current state of memory in a text file
showhelp(name) SHOWHELP displays a help file
showinstructions SHOWINSTRUCTIONS displays a list of BM instructions
step(machine) STEP carries out one execution step on a BM
string2val(type, inp) STRING2VAL returns value from text entry in display
writetext(text, file) WRITETEXT writes text to a file
Contents.m
Contents.m
todo.m
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from Extended Brookshear Machine emulator and assembler by David Young
Emulator and assembler for a simple computer, a teaching aid for computer science courses.

showinstructions

function showinstructions
%SHOWINSTRUCTIONS displays a list of BM instructions
%   SHOWINSTRUCTIONS uses MSGBOX to display a quick-reference list of
%   instructions for the BM.
%
%   There does not seem to be a way to change the font - it would be better
%   larger, and fixed-width.
%
%   It might be nice to use INSTR2STRING to generate the message, for
%   consistency.

%   Copyright 2008 University of Sussex and David Young

msgbox({ ...
    'BM instructions' ...
    '' ...
    '0FFF   No operation' ...
    '1rxy   Load memory[xy] into Rr' ...
    '2rxy   Load value xy into Rr' ...
    '3rxy   Store Rr in memory[xy]' ...
    '40rs   Move Rr to Rs' ...
    '5rst   Add as ints Rs, Rt, put result in Rr' ...
    '6rst   Add as floats Rs, Rt, put result in Rr' ...
    '7rst   OR each bit of Rs, Rt, put result in Rr' ...
    '8rst   AND each bit of Rs, Rt, put result in Rr' ...
    '9rst   XOR each bit of Rs, Rt, put result in Rr' ...
    'Ar0x   Rotate  Rr x bits right' ...
    'Brxy   Jump to xy if Rr equals R0' ...
    'C000   Halt' ...
    'D0rs   Load memory[Rs] into Rr' ...
    'E0rs   Store Rr in memory[Rs]' ...
    'Frxt   Jump to address in Rt if Rr test R0' ...
    '        x=0 means test is equals' ...
    '        x=1 means test is not equal' ...
    '        x=2 means test is greater or equal' ...
    '        x=3 means test is less or equal' ...
    '        x=4 means test is greater than' ...
    '        x=5 means test is less than' ...
    '' ...
    'For full descriptions, click Help' ...
    }, ...
    'Instructions', ...
    'replace');
end

Highlights from Extended Brookshear Machine emulator and assembler

Highlights from
Extended Brookshear Machine emulator and assembler