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<HTML> |
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<HEAD> |
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<TITLE>SAM</TITLE> |
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</HEAD> |
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<BODY> |
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|
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<H1>SAM</H1> |
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<CITE> |
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"Frodo! Mr.Frodo, my dear!" cried Sam,<BR> |
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tears almost blinding him. "It's Sam, I've come!" |
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</CITE> |
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<HR> |
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Frodo has a built-in machine language monitor that can be activated at any |
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time by pressing F9 (Unix) or selecting the appropriate menu item (BeOS/AmigaOS/MacOS): |
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SAM (Simple Assembler and Monitor). It provides full access to the memory |
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and hardware of the emulated C64 and 1541 (under BeOS, you must only start |
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SAM if you launched Frodo from the Shell).<P> |
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|
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SAM is controlled by a command-based interface, all numbers are in hex. |
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With the command "h" you can display a list of all commands. The command |
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"x" quits SAM and returns to Frodo.<P> |
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|
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SAM has two modes of operation, indicated by the prompt "C64>" or "1541>". |
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You can switch between them with the "64" and "1541" commands. In "C64" |
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mode, all commands that access memory or the CPU operate on the memory/CPU |
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of the emulated C64. In "1541" mode, they operate on the emulated 1541 |
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(this is only useful if the processor-level 1541 emulation is turned |
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on).<P> |
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|
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All commands that access the C64 memory use the memory configuration set |
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with the "k" command. On starting up SAM, the configuration is set to the |
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one the processor is in. Accesses from within SAM have the same effect as |
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accesses of the emulated processor. This affects especially the I/O |
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registers: a memory dump of $dc00-$de00 clears pending CIA interrupts as |
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SAM reads from $dc0d and $dd0d. With the "v" commands, you can examine the |
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state of the I/O chips without modifying the state of the emulation.<P> |
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In all places where SAM expects a number (except in the assembler) you can |
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also enter an expression of hex numbers containing '+', '-', '*', '/' and |
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parens. Commands that create a longer output can be interrupted with |
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Ctrl-C.<P> |
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Here is a description of all commands ('[]' marks a parameter than can be |
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left out, '{}' marks a parameter that can be repeated many times. If a |
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[start] parameter is left out, SAM continues at the address where the last |
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command stopped):<P> |
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<PRE> |
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a [start] Assemble |
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</PRE><P> |
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starts the assembler at the address "start". SAM always prints the address |
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where the next instruction will be written to. The syntax of the |
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instructions conforms to the standard except for shift/rotation |
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instructions in the "accumulator" addressing mode. Those have to be entered |
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without operand, e.g. "lsr" instead of "lsr a". Entering a blank line quits |
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the assembler and returns to the command mode of SAM.<P> |
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<PRE> |
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b [start] [end] Binary dump |
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</PRE><P> |
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displays the memory from "start" to "end" byte-wise binary. With this |
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command, you can view character sets.<P> |
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<PRE> |
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c start end dest Compare memory |
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</PRE><P> |
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compares the memory in the range from "start" to (and including) "end" |
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with the memory at "dest". The addresses of all different bytes and the |
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total number of differences (decimal) are printed.<P> |
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<PRE> |
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d [start] [end] Disassemble |
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</PRE><P> |
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disassembles the memory from "start" to "end". Undocumented opcodes are |
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markes with a star '*'.<P> |
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<PRE> |
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e Show interrupt vectors |
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</PRE><P> |
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shows the currently active interrupt vectors of the 6510 (C64) or 6502 |
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(1541) and (in C64 mode, if the Kernal ROM is mapped in) of the Kernal.<P> |
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<PRE> |
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f start end byte Fill memory |
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</PRE><P> |
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fills the memory in the range from "start" to (and including) "end" with |
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the value "byte".<P> |
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<PRE> |
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i [start] [end] ASCII/PETSCII dump |
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</PRE><P> |
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shows the memory from "start" to "end" as ASCII/PETSCII characters.<P> |
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<PRE> |
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k [config] Show/set C64 memory configuration |
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</PRE><P> |
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"k" without parameters shows the memory configuration that is set for SAM, |
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"k" with parameter modifies it. On exiting SAM, the configuration set with |
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the processor port is reactivated. The memory configuration has no effect |
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in 1541 mode. The 8 possible configurations are: |
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<PRE> |
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# $a000-$bfff $d000-$dfff $e000-$ffff |
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---------------------------------------- |
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0 RAM RAM RAM |
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1 RAM Char ROM RAM |
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2 RAM Char ROM Kernal ROM |
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3 Basic ROM Char ROM Kernal ROM |
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4 RAM RAM RAM |
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5 RAM I/O RAM |
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6 RAM I/O Kernal ROM |
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7 Basic ROM I/O Kernal ROM |
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</PRE> |
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<PRE> |
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l start "file" Load data |
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</PRE><P> |
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loads the contents of the specified file into memory starting from address |
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"start". The file name must be enclosed in quotation marks even if it |
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contains no spaces. This command cannot be used to load C64 programs as |
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it doesn't respect the embedded load address in the programs.<P> |
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<PRE> |
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m [start] [end] Memory dump |
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</PRE><P> |
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displays the memory from "start" to "end" as hexadecimal numbers and ASCII |
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characters.<P> |
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<PRE> |
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n [start] [end] Screen code dump |
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</PRE><P> |
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displays the memory from "start" to "end" as ASCII characters, interpreting |
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each byte as a screen code of the standard character set.<P> |
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<PRE> |
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o ["file"] Redirect output |
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</PRE><P> |
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When a file name is specified, all following output is redirected to this |
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file. The file name must be enclosed in quotation marks even if it contains |
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no spaces. Entering "o" without parameters closes the file and directs the |
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output into the window of SAM again.<P> |
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<PRE> |
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p [start] [end] Sprite dump |
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</PRE><P> |
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displays the memory from "start" to "end" binary with three bytes per line. |
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With this command, you can display sprite data.<P> |
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<PRE> |
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r [reg value] Show/set CPU registers |
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</PRE><P> |
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"r" without parameters shows all 6510 (C64) or 6502 (1541) registers and |
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flags and the instruction at the address specified by the program counter. |
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For the 6510, "DR" and "PR" are the data direction register and data |
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register of the processor port. To modify a register, give its name ("reg") |
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and the new value ("value") as parameters.<P> |
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<PRE> |
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s start end "file" Save data |
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</PRE><P> |
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writes the memory from "start" to (and including) "end" to the specified |
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file. The file name must be enclosed in quotation marks even if it contains |
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no spaces. This command cannot be used to save C64 programs as it doesn't |
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save a load address in the file.<P> |
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<PRE> |
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t start end dest Transfer memory |
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</PRE><P> |
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transfers the memory from "start" to (and including) "end" to "dest". |
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Source and destination may overlap.<P> |
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<PRE> |
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vc1 View CIA 1 state |
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</PRE><P> |
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shows the state of CIA 1 ($dc00).<P> |
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<PRE> |
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vc2 View CIA 2 state |
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</PRE><P> |
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shows the state of CIA 2 ($dd00).<P> |
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<PRE> |
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vf View floppy state |
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</PRE><P> |
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shows the state of the processor-level 1541 emulation.<P> |
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<PRE> |
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vs View SID state |
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</PRE><P> |
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shows the state of the SID.<P> |
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<PRE> |
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vv View VIC state |
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</PRE><P> |
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shows the state of the VIC.<P> |
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<PRE> |
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x Return to Frodo |
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</PRE><P> |
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quits SAM and returns to Frodo.<P> |
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<PRE> |
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: addr {byte} Modify memory |
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</PRE><P> |
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writes the space-separated values "byte" into memory starting at "addr".<P> |
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<PRE> |
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1541 Switch to 1541 mode |
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</PRE><P> |
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switches to 1541 mode. All commands that access memory or the CPU will then |
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operate on the emulated 1541 (processor-level).<P> |
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<PRE> |
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64 Switch to C64 mode |
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</PRE><P> |
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switches to C64 mode. All commands that access memory or the CPU will then |
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operate on the emulated C64.<P> |
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<PRE> |
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? expression Calculate expression |
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</PRE><P> |
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calculates the value of the given expression and displays it in decimal |
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and hexadecimal.<P> |
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</BODY> |
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</HTML> |
