+ `    Bypass aliases

    Executes a command without checking the alias table.
    
      `<command>
      
    Allows access to commands that are blocked by aliases. This also provides an
    escape hatch if you somehow manage to alias over both the alias set (as) and
    alias clear (ac) commands.

+ ?    Evaluate expression

    Prints the value of an expression.
    
      ? <expression>
      
    The expression may contain the following elements, from highest to lowest
    precedence:
    
     Constants
      iii      Integer
      $hhh     Hex integer
      %bbbb    Binary integer
      ii:iiii  Banked address (decimal)
      $hh:hhhh Banked address (hex)

     Variables
      pc       PC register
      x        X register
      y        Y register
      s        S register
      p        P register
      hpos     ANTIC horizontal position counter
      vpos     ANTIC vertical position counter
      address  PC or memory address from current breakpoint
      value    Value written from current access write breakpoint
      xbankreg  Bank register value for PORTB extended memory
      xbankcpu  PORTB extended memory bank (CPU)
      xbankantic  PORTB extended memory bank (ANTIC)
      @t0-t9   Temporaries
      @ra      Return address (if RTS executed immediately)
     
     Grouping
      (exp)    Subexpression
      
     Unary operators
      db addr  Read memory unsigned byte
      dsb addr Read memory signed byte
      dw addr  Read memory unsigned word
      dsw addr Read memory signed word
      dsd addr Read memory signed double word (32-bit)
      +        Unary plus
      -        Unary minus
      <        Unary low byte (bits 0-7, as unsigned byte)
      >        Unary high byte (bits 8-15, as unsigned byte)
      !        Logical negation
      
     Multiplicative operators
      *        Multiply
      /        Integer division (truncation toward zero)
      %        Modulus (a%b = a - a/b*b)
      
     Additive operators
      +        Add
      -        Subtract
      
     Relational operators
      <        Less-than
      <=       Less-equal
      >        Greater-than
      >=       Greater-equal
      =        Equal
      !=       Not equal
     
     Bitwise operators 1
      &        Bitwise AND
      
     Bitwise operators 2
      |        Bitwise OR
      ^        Bitwise XOR
      
     Logical operators 1
      and      Logical AND
      
     Logical operators 2
      or       Logical OR
      
     Ternary operators
      ?:       Conditional operator
      
    Spaces are not significant except to delimit tokens. 
    
    Symbol names may also be used in expressions, but care should be taken
    to distinguish between "symbol", which evaluates to the symbol's address,
    and "db symbol" or "dw symbol", which reads a byte or word at the address.
    Symbols that conflict with other tokens can be forced by prefixing with
    #, i.e. #address. A symbol from a specific module may be referenced with
    the syntax modname!symname.
    
    All expressions are evaluated with 32-bit signed two's-complement integer
    arithmetic. Logical operators operate according to the rules of the C
    programming language, where 0 signifies false, a non-zero value is
    interpreted as true, and true is encoded as 1.
    
    Due to a conflict with the bank operator, the ternary operator may
    sometimes require a space between a constant and the ':' in order to be
    parsed as intended.
    
    Examples:
    
      vdslst              Address of DLI vector ($0200)
      dw vdslst           DLI routine address
      dw vdslst+2         DLI routine address + 2
      dw vdslst + 2       DLI routine address + 2
      dw (vdslst+2)       SIO proceed IRQ routine address

+ a    Assemble

    Invoke 6502 miniassembler.
  
      a <address>
    
    Allows entry of 6502 assembly language code starting at a particular
    address. Enter one line at a time, and enter a blank line to end.
    
    Labels may be entered and referenced; created labels are entered into
    the custom symbol table. Labels must be defined before use and forward
    references are not allowed.
    
    Auto-increment syntax is allowed: LDA $1000,X+ -> LDA $1000,X / INX
    
    Statements may be stacked to share an operand: LDA:RNE VCOUNT
    
    Pseudoinstruction macros supported:
        MVA src dst -> LDA src / STA dst
        MVX src dst -> LDX src / STX dst
        MVY src dst -> LDY src / STY dst
        MWA src dst -> Move 16-bit data using LDA/STA
        MWX src dst -> Move 16-bit data using LDX/STX
        MWY src dst -> Move 16-bit data using LDY/STY
        Rcc -> Bcc *
        Scc:<insn> -> Bcc next / <insn> / next:
        Jcc -> branch + jump
        INW/DEW -> INC/DEC / BNE / INC/DEC
        INL/DEL -> INC/DEC 24-bit "long" value
        IND/DED -> INC/DEC 32-bit "double-word" value
        ADD -> CLC+ADC
        SUB -> SEC+SBC
        ADB/SBB src1 src2 dst -> Store src1-src2 in dst (8-bit)
        ADW/SBW src1 src2 dst -> Store src1-src2 in dst (16-bit)
        CPB/CPW/CPL/CPD src1 src2 -> Compare src1-src2 (8/16/24/32-bit)
        PHR -> Push A, X, Y
        PLR -> Pop Y, X, A
        
    Supported directives:
        ORG address            Shift code origin to new address

+ a8   Set Atari800-compatible command aliases

    Sets compatibility aliases for commands from the Atari800 emulator debugger.
    
      a8
    
    The following commands are mapped:
    
        cont      g            Continue (go)
        show      r            Show registers
        stack     k            Show stack
        setpc *   r pc *       Change PC register
        seta *    r a *        Change A register
        setx *    r x *        Change X register
        sety *    r y *        Change Y register
        sets *    r s *        Change S register
        setn [*]  r p.n */1    Set N flag
        setv [*]  r p.v */1    Set V flag
        setd [*]  r p.d */1    Set D flag
        seti [*]  r p.i */1    Set I flag
        setz [*]  r p.z */1    Set Z flag
        setc [*]  r p.c */1    Set C flag
        clrn      r p.n 0      Clear N flag
        clrv      r p.v 0      Clear V flag
        clrd      r p.d 0      Clear D flag
        clri      r p.i 0      Clear I flag
        clrz      r p.z 0      Clear Z flag
        clrc      r p.c 0      Clear C flag
        c         e            Change (enter)
        d         u            Disassemble (unassemble)
        f * * *.. f * L>* *..  Fill memory
        m * [*]   db * [L>*]   Memory list (display bytes)
        s * *..   s * [L>*]..  Search memory
        sum * *   .sum * L>*   Compute memory sum
        bpc       bp           Set PC breakpoint
        history   h            Show CPU history
        g         t            Go one insn (trace)
        r         gr           Execute until return
        b         bl/bc/bp     Breakpoints
        antic     .antic       Display ANTIC status
        gtia      .gtia        Display GTIA status
        pia       .pia         Display PIA status
        pokey     .pokey       Display POKEY status
        dlist     .dumpdlist   Show display list
        labels    .loadsym     Load symbols
        coldstart .restart     Cold-reset the simulation
        warmstart .warmreset   Warm-reset the simulation
        help      .help        Display command help

^ ac, al, as  Manage command aliases
> ac   Clear all command aliases
> al   List command aliases
> as   Set or unset command alias

    Set, clear, or list aliases for debugger commands.
    
        ac                    (Clear all aliases)
        al                    (List aliases)
        as <alias> <command>  (Set an alias)
        as <alias>            (Unset an alias)
        
    Allows you to set alternate name aliases for commands. If an alias is set
    with the same name as a standard debugger command, the alias takes
    precedence. An alias always redirects to a standard command; an alias
    cannot point to another alias.
    
    To access a command that is blocked by an alias, prefix the command name
    with a backtick (`).

+ ap   Add command alias pattern

    Adds a command alias pattern for a debugger command.
    
        ap "pattern"          (Clear alias pattern)
        ap "pattern" "alias"  (Set alias pattern)
        
    Allows a command alias to be set that matches and transforms arguments.
    The pattern string matches a command and optional arguments, while the
    alias string determines the resulting command and arguments.
    
    Tokens %0, %1, %2... up through %9 can be used to match and substitute
    parameters. They must appear as or at the end of an argument in the
    pattern. The special token %* can also be used to capture and recall
    a variable number of remainder of arguments (varargs). It can only
    capture and recall entire parameters.
    
    If multiple alias patterns are declared for the same command, they are
    added and tested in order and the first one to match is used. Therefore,
    patterns should be added from least to most general.
    
    Examples:
    
        ap "foo" "bar"
        
           Matches the command "foo" with no arguments and executes "bar"
           in response.
           
        ap "foo x" "bar y"
        
           Matches the command "foo" with a single argument "x" and executes
           the command "bar y" in response.
           
        ap "foo %1 %2 %*" "bar %1 L>%2 %*"
        
           Matches the command "foo" with two or more arguments and executes
           the command "bar" with the second argument prefixed with L>.
           
        ap "foo %1 L%2" "bar %1 %2"
        
           Matches the command "foo" with exactly two arguments and the second
           argument prefixed with L, and executes "bar" with the second
           argument stripped of its prefix.
           
    See also: ac, al, as

+ ba   Break on memory access

    Set or clear a memory access breakpoint.
    
      ba [-n] [-k] [-q] [-g <group>] r <address> [L<length>] ["cmd"]
                                         (Break on memory read)
      ba [-n] [-k] [-q] [-g <group>] w <address> [L<length>] ["cmd"]
                                         (Break on memory write)
      ba r/w *         (Clear memory read/write access breakpoints)
      
    Memory access breakpoints cause the emulator to stop whenever the CPU
    core reads or writes a particular address. There can be an unlimited
    number of both read and write breakpoints. If a length greater than 1
    byte is specified, a range breakpoint is created.
    
    If a quoted string is supplied, it is run as a command whenever the
    breakpoint is hit.
    
    DMA accesses, such as by ANTIC or VBXE, do not trip access breakpoints.
    All breakpoints are by CPU address and trip regardless of any
    bankswitching or other memory overlays.
    
    Memory read breakpoints can be tripped by false reads from the CPU core.
    This happens for certain indexed operations. Although generally invisible
    to normal program operation, these false reads are real and can cause
    malfunctions with memory mapped hardware, such as cartridge banking
    registers that are sensitive to reads. False writes are rarer but can
    occur with read/modify/write instructions.

    The -n, -k, -q, and -g options are the same as for the bp command.
    
    Using * as the address will clear all access breakpoints of the
    indicated type.

    See also: bp (set breakpoint)

+ bc   Clear breakpoint(s)

    Clear PC, memory, or expression breakpoints.
    
      bc <index>     (Clear a breakpoint)
      bc *           (Clear all breakpoints)
    
    Removes a breakpoint by index, or if * is specified, all breakpoints.
    This works for any breakpoint listed by the bl (breakpoint list)
    command.

    By default 'bc' only clears breakpoints in the main breakpoint
    group. Breakpoints in other groups can be cleared by prefixing with
    with the group name in a period, e.g. foo.1. Similarly, an entire
    group can be cleared with 'bc group.*'.
    
    See also: ba, bp, bl, bx  
      
+ bl   List breakpoints

    Lists all currently set breakpoints.

      bl [-a]        (List breakpoints)
      
    Displays a list of all breakpoints. The displayed breakpoint indices
    can be used in other commands such as bc (breakpoint clear).

    Flags displayed on each breakpoint:

      K     - auto-clear on reset
      O     - one-shot
      PC    - break on CPU PC address
      R     - break on read access
      W     - break on write access
    
    Deferred breakpoints are also listed and are ones that haven't been
    bound to an actual address yet. These remain inactive until symbols
    have been loaded that contain an entry for the source file/line
    reference.

    -a lists breakpoints in all groups. Normally only breakpoints in the
    main group are listed.
    
    See also: bc, bl, bp, bx

+ bp   Set breakpoint

    Set a breakpoint at a PC address.
    
      bp [-n] [-k] [-q] [-g group] <address> ["command"]
      bp [-n] [-k] [-q] [-g group] `file:line` ["command"]
      
    Sets a PC breakpoint in the CPU core, which cause the emulator to stop
    when the PC is equal to the address of a breakpoint. There are no
    limits to the number of PC breakpoints. Breakpoints do not modify
    memory and work even after the location has been modified; they also
    fire at an address regardless of any bank switching.

    The -n option creates a non-stopping breakpoint after which execution
    continues.

    Breakpoints created with -k are automatically cleared on reset.

    -g creates the breakpoint in a named group. Named groups have a separate
    numbering than the main user group and are not visible by default.

    -q suppresses normal output of the command.
    
    If a command is specified, the command is executed when the breakpoint
    fires. Multiple commands may be specified using ; as a separator.
    The normal breakpoint hit message is suppressed, but execution will
    stop after the commands are executed unless a command is also issued
    to continue execution. This can be used to implement tracepoints.
    
    Example: bp pc "? db(rtclok); g"

    Breakpoints can also be set on source lines using source notation:
    
      bp `library.s:207`
      
    The breakpoint is set immediately if symbols are available. Otherwise,
    a deferred breakpoint is created and the breakpoint is bound to the
    code address when the symbols are loaded.    
    
    See also: ba, bs

+ bt   Set breakpoint with trace (tracepoint)

    Set a tracepoint at a PC address.
    
      bt [-k] [-q] [-g group] { <address> | `file:line` }
             format [arguments...]

      bt [-k] [-q] [-g group] { <address> | `file:line` }
             format [arguments...] -- [return-arguments...]
      
    Sets a non-stopping breakpoint at a PC address or source location
    with a command to print a trace line on the console when the breakpoint
    is hit (tracepoint). The breakpoint location is the same as for the
    bp (set breakpoint) command and the formatting arguments are the same
    as for the .printf command.

    The -k, -q, and -g options work the same as for the bp command.
    
    This command is equivalent to using the bp -n command with a breakpoint
    command of the form:
    
      `.printf <format> <arguments...>

    The @ts variable can be used to substitute the output of the last
    .sprintf command as the format string.

    The second form of the command with '--' allows a return tracepoint to
    be set. The format string is evaluated with the first set of arguments
    prior to -- when the tracepoint is first hit. A second, one-time
    tracepoint is then set at the return address (@ra) with the resulting
    string as the format, expanded by the second set of arguments.

    Examples:

       bt siov "SIOV command=$%02X aux=$%04X" db(dcomnd) dw(daux1)
       bt fadd "FADD(%g+%g) = %%g --> $%04X" fr0 fr1 @ra -- fr0
    
    See also: bp, .printf, .sprintf
    
+ bx   Break on expression (conditional breakpoint)

    Set a breakpoint conditional on an expression.
    
      bx [-k] [-q] [-n] [-g group] <expression> ["command"]
      
    Creates a breakpoint that only activates when the expression is true.    
    In addition to the normal expression elements, conditional breakpoints
    may have the following additional clauses:
    
      read=<address>    Read access to address
      write=<address>   Write access to address
      read >[=] <lo> and read <[=] <hi>      Read access to address range
      write >[=] <lo> and write <[=] <hi>    Write access to address range
      
    The expression must have an identifiable PC, read access, or write
    access check, and only one read or write access or access range may
    be included.
    
    The debugger can optimize some conditional expressions for faster
    evaluation, such as removing redundant logical negation (!) operators
    and folding constants. An error is reported if the conditional
    expression is determined to always evaluate to true or false.
    
    If the expression reduces to a single PC or access check, the result is
    the same as the equivalent bp or ba command.
    
    Examples:
    
      bx "pc=$4000 and y=4"
      bx "write=rtclok+2 and db(rtclok+2)=$04"
      bx "write=rtclok+2 and pc>$c000"
      bx "write = consol and value != $08"
      bx "read<$fffa and db(pc)!=$20 and db(pc)!=$60 and read>=$d800"
      
    If a command is specified, it is executed when the breakpoint trips;
    see the bp (breakpoint) command for details.
    
    Example:
    
      bx "pc=ciov and x=$10" "r; g"
    
    The -k, -q, and -g options work the same as for the bp command.

    See also: ? (evaluate expression), bp (breakpoint)

+ bs   Break on disk sector

    Set a breakpoint when D1: reads a particular virtual disk sector.
    
      bs <sector>    (Set disk sector breakpoint)
      bs *           (Clear disk sector breakpoint)
      
    Stops emulation when the first disk drive (D1:) receives a request
    to read a particular virtual disk sector.

^ da, db, dbi, dd, df, di, dw   Display memory
> da   Display ATASCII string
> db   Display bytes
> dbi  Display bytes w/ INTERNAL dump
> dd   Display double words
> df   Display decimal float
> di   Display INTERNAL string
> dw   Display words

    Shows the contents of memory with a particular interpretation.
    
      da [<xaddress> [L<length>]]   (Display ATASCII string)
      db [<xaddress> [L<length>]]   (Display bytes)
      dbi [<xaddress> [L<length>]]  (Display bytes with INTERNAL text)
      dd [<xaddress> [L<length>]]   (Display 32-bit double words)
      df [<xaddress> [L<length>]]   (Display decimal float)
      di [<xaddress> [L<length>]]   (Display INTERNAL string)
      dw [<xaddress> [L<length>]]   (Display 16-bit words)
      
    Length specifies the number of elements to display.
    
    The display commands read memory in debug mode and do not trigger side
    effects that would normally be caused by a CPU read, such as clearing
    PIA interrupts or switching cartridge banks.
    
    If no address or length is given, memory dumping continues from the
    end of the last continuable operation.
    
> dy   Display binary

    Shows the contents of memory as binary.
    
      dy [-c <chars>] [<xaddress> [L<length>]]
      
      -c: set '1' bit character, or both 0/1 bit chars

+ e    Enter (alter) data in memory

    Modifies a block of memory with new data.
    
      e <xaddress> <expr> [<expr>...]

    Each successive byte is set to the value of an expression. Expressions
    must evaluate to unsigned byte range (0-255); use the low byte (<)
    operator if necessary to forcibly truncate values.
    
    Writes by the enter (e) command have the same effect as CPU writes,
    including triggering side effects when hardware registers are accessed.
    
    See also: f (fill memory)

+ f    Fill memory

    Fills a block of memory with a pattern.
    
      f <xaddress> L<length> <value>...
      
    Each successive byte is set to the value of an expression until <length>
    bytes have been filled. Expressions must evaluate to unsigned byte range
    (0-255); use the low byte (<) operator if necessary to forcibly truncate
    values. The pattern repeats until the specified length is filled.
    
    Examples:
      f 2000 L1000 aa 55
      f 2000 L400 8d <serout >serout
      f $01:0000 L10000 0
    
    See also: e (enter), fbx (fill bytes with expression)

+ fbx  Fill bytes with expression

    Fills a block of memory by evaluating an expression for each location.
    
      fbx <xaddress> L<length> <expression>
      
    The expression is evaluated once for each byte in the range and its low
    byte is used to set the value of that location. The VALUE expression
    token evaluates to the current zero-based index in the range (0-255 only)
    and the WRITE expression token gives the current extended address.
    
    Examples:
      fbx 8000 L1000 value
      fbx 8000 L1000 <write
      fbx 8000 L1000 "(value-value%80) + (value%40)*2 + (value%80)/40"
      
    See also: f (fill)

+ g    Go

    Resume execution.
    
      g [-n] [-s]
      
    By default, the g (Go) command disables source mode debugging. The -n
    switch preserves the current mode and the -s switch forces source mode.
    
    See also: .sourcemode

+ gf   Go until frame end

    Resume execution until the end of the current frame.
    
      gf
      
    Resumes execution until the beginning of scan line 0 of the next frame.
    If the beam position is currently at the beginning of scan line 0, an
    entire frame is executed.

+ gr   Go until return (step out)

    Resume execution until the current function is exited.
    
      gr
      
    Resumes execution until the stack pointer rises above the level of
    the current function. Any child functions executed due to a JSR
    instruction or an interrupt are run in their entirety.

+ gs   Go until scanline

    Resume execution until the beginning of a particular scanline.
    
      gs <scanline>
      
    If the current scanline is specified, an entire frame is executed.

+ gt   Go with tracing enabled

    Resume execution with per-instruction tracing enabled.
    
      gt
      
    During traced execution, the current beam location, PC, registers, and
    instruction are logged.

+ h    Show CPU history

    Display history of CPU instructions executed.

      h [-i] [-c] [-s <startidx>] [<count> [<pattern>]]
      
      -i: Show only interrupt routine execution
      -c: Compress loops
      -s: Start from position
      <count>: Number of entries to display
      <pattern>: Glob wildcard (?*) to search for
    
    The "record instruction history" setting must be enabled in CPU options
    for the history command to work.
    
    The history UI pane contains a more powerful history preprocessor that is
    also able to identify subroutines and is recommended for serious history
    review.

+ hma  Show heat map accesses

    Shows read and write accesses to memory.
    
      hma [<address> [L<length>]]
      
    The requested memory range is broken down into contiguous ranges that
    have been read and written by the CPU.
    
    Note that accelerated accesses from high-level emulation (HLE) and from
    ANTIC are not shown in the heat map.
    
    See also: hmc (clear heat map)

+ hmc  Clear heat map

    Clears all tracking data in the heat map.
    
      hmc
      
    All registers and memory locations are marked as preset.
    
    See also: hme (heat map enable)

+ hmd  Dump heat map memory status

    Dumps the tracking status of memory locations in the heat map.
    
      hmd <address> [L<length>]
      
    The status of a memory location may be one of the following:
    
      Unknown:       Source of data was not tracked.
      Preset:        Source was not modified since the last clear.
      Immediate:     Source is the argument of an immediate-mode insn.
      Computed:      Source is from computation on the CPU.
      
    Data sources are tracked through load/store instructions and through
    the registers such that the original load source is propagated instead
    of showing the copy routine itself as the data source.

    See also: hmc (clear heat map), hme (heat map enable)

+ hme  Enable or disable heat map

    Enables or disables heat map tracing.
    
      hme on                (Enable heat map)
      hme off               (Disable heat map)
      
    The heat map tracks the source of data as it flows through registers and
    memory, as well as any read or write accesses to memory.
    
    See also: hma (show heat map accesses), hmc (heat map clear),
              hmd (dump heat map memory status),
              hmr (heat map register status).

+ hmr  Show heat map register status

    Dump CPU register status being tracked by heat map.
    
      hmr
      
    The sources of the data in the A, X, and Y registers is shown if known.
    
    See also: hmc (heat map clear), hme (heat map enable)

+ k    Show call stack

    Display a list of return addresses on the stack.
    
      k
      
    The call stack is computed by virtualized execution, so it may be
    incorrect if bankswitching or other complex techniques are involved.
    Note that because return addresses are displayed, the call stack
    will not show parent call sites to children that never return in
    normal execution.

^ lfd, lfe, lfl, lft   Logging filter control
> lfd  Disable logging channel
> lfe  Enable logging channel
> lfl  List logging filter settings

    Display or modify logging filter settings.
    
      lfd <channel>|*   Disable logging channel
      lfe <channel>|*   Enable logging channel without timestamps
      lfl               List logging channels
      
    The logging filter controls which events from the simulation are shown
    in the debug output window during execution.

> lft  Enable logging channel with tagging

      lft [-t] [-c] <channel>|*
      
    Enables a logging channel with prefixes indicating running status:
    
      -t   Include beam position timestamp.
      -c   Include cassette tape position.
      
    If no switches are supplied, -t is assumed.

+ lm   List modules

    Display a list of currently known modules and any loaded symbols.
    
      lm

+ ln   List nearest symbol

    Display the closest symbol to a given address.
    
      ln <address>
      
    The closest symbol is the one with the highest address that is equal to
    or lower than the given address.

+ m    Move memory

    Move a block of memory to another location.
    
      m <address> L<length> <dest-address>
      
    Memory in the source block is copied to a new block starting at the
    destination address. If the source and destination blocks overlap, a
    descending copy is used if needed to copy correctly. This is not
    guaranteed if aliased memory windows are used, such as copying from
    $4000 to x:$100 with the CPU extended memory window active.

+ o    Step over

    Execute one instruction, stepping over any subroutine calls.
    
      o
      
    This is the same as (t)race, except that if a JSR or an interrupt is
    encountered, execution continues until the subroutine exits.

+ r    Registers

    Display or modify register values.
    
      r                (Display registers)
      r <reg> <value>  (Modify register)
      
    Registers that can be modified are: PC, A, X, Y, S, and P. The flags in
    the P register can also be individually toggled:
    
      p.n    Negative (sign) flag
      p.v    Overflow flag
      p.d    Decimal mode flag
      p.i    Interrupt mask flag
      p.z    Zero flag
      p.c    Carry flag
      
    The break flag cannot be modified as it does not exist in the P register,
    only in the image of P pushed on the stack during interrupt entry.
    
    In 65C816 mode, the following additional registers are available:
    
      c      16-bit accumulator (B:A)
      d      Direct page register
      b/dbr  Data bank register
      k/pbr  Program bank register
      p.m    Accumulator size flag
      p.x    Index size flag
      e      Emulation flag

+ s    Search memory

    Searches memory for a specific pattern.
    
      s <xaddress> L<length> <value>...
      
    All starting addresses of blocks of memory that contain the given byte
    pattern are reported. Expressions must evaluate to unsigned byte range
    (0-255); use the low byte (<) operator if necessary to forcibly truncate
    values.
    
    Examples:
    
      s 0 L10000 00 04 A5
      s E800 L2800 <vimirq >vimirq

+ st   Static trace

    Statically traces program execution and marks labels.
    
      st <baseaddr> [<restrictbase> L<restrictlength>]
      
    The st command examines program code and finds all static program traces
    by following absolute JMP/JSR and relative branch instructions. The custom
    symbol table is then populated with labels for each jump or branch target.
    
    Static tracing is only capable of following traces by references that are
    statically embedded within the code. Dynamic references through jump tables
    or vectors cannot be seen by the static tracer.
    
    If restrictbase and restrictlength are specified, only traces within the
    given restricted range are followed. This is useful for contraining tracing
    to within a specific module and avoiding bogus tracing into other regions,
    such as RAM where dynamic code is kept.

+ t    Trace (step one instruction) (F11)

    Execute one instruction, stepping into a subroutine or interrupt.
    
      t

+ u    Unassemble

    Disassemble CPU code at a given address.
    
      u [<address> [L<length>]]
      
    If no address is given, disassembly continues from the end of the last
    continuable command.

^ vta, vtc, vtl, vtr    Verifier target control
> vta  Verifier target add
> vtc  Verifier target clear
> vtl  Verifier target list
> vtr  Verifier target reset

    Add, clear, or list verifier allowed OS entry targets.
    
      vta <address>    (Add allowed target)
      vtc <address>    (Clear allowed target)
      vtc *            (Clear all allowed targets)
      vtl              (List allowed targets)
      vtr              (Reset allowed targets)
      
    Manages the list of allowed kernel entry targets allowed by the verifier.
    The verifier checks for improper dependencies on internal OS routines
    by forcing a debug break if it sees a control transfer into the OS ROM
    with an entry point not on the allowed target list. This detection may
    misfire with an OS ROM that contains extra entry points or with a routine
    that self-modifies its code with a vector address. The vt* commands allow
    the target list to be modified to exclude valid targets from detection.

^ wb, wc, wl, ww, wx   Watch data
> wb   Watch byte
> wc   Watch clear
> wl   Watch list
> ww   Watch word
> wx   Watch expression

    Continuously display the value of a memory location on-screen.
    
      wb <address>     (Watch byte)
      ww <address>     (Watch word)
      wx <expr>        (Watch expression)
      wl               (Watch list)
      wc               (Clear all watches)
      
    Watched values are sampled and displayed each frame. Up to eight watches
    can be active at any one time.
    
    See also: ? (evaluate expression)

+ x    Examine symbols

    List symbols whose names match a given pattern.
    
      x <pattern>      (Examine symbols with name pattern)
      x <pat>!<pat>    (Examine symbols with module and name patterns)
      
    The x command lists symbols according to a wildcard pattern, with ? and
    * characters representing one and zero+ unknown characters. If a simple
    pattern is supplied, all symbols matching that pattern are reported; if
    a module pattern is supplied, only symbols matching both the module and
    name patterns are reported.
    
    Examples:
    
      x *              Lists all symbols
      x hardware!*     Lists all hardware symbols
      x kernel*!a*     Lists all symbols starting with "a" in kernel modules
      
    See also: .loadsym, .unloadsym, lm (list modules)

^ ya, yc, yd, yr, yw   Manage manual symbol table
> ya   Add manual symbol
> yc   Clear manual symbols
> yd   Delete manual symbol
> yr   Read manual symbol table
> yw   Write manual symbol table

    Add or remove symbols from the manual symbol table.
    
      ya <name> <address> [L<length>]  (Add manual symbol)
      yc                               (Clear manual symbols)
      yd <address>                     (Delete manual symbol)
      yr <filename>                    (Read manual symbol table)
      yw <filename>                    (Write manual symbol table)
      
    The manual symbol table allows on-the-fly naming of addresses in memory.
    Any symbols added to the manual symbol table can be used for address
    specification and decoding as any other symbol.

+ .antic       Display ANTIC status
+ .bank        Show memory bank state

+ .base        Set numeric parsing base

    Selects decimal or hexadecimal as the default parsing base for numbers.

      .base dec            (Set base 10 for numbers)
      .base hex            (Set base 16 for numbers)
      .base mixed          (Set base 10 with 16 shortcut for numbers)
      
    The .base command changes whether numbers in expressions are by default
    parsed as decimal (base 10) or hexadecimal (base 16). The default is
    mixed, which selects hex for simple numbers/addresses and decimal for
    complex expressions. This permits unprefixed hex for simple addresses
    while avoiding unexpected hex values in expressions.
    
    Examples of how various expressions are interpreted:
    
       Expression       Hex        Dec        Mixed
       ---------------------------------------------------------------
       10               $10        $0A        $0A
       $10              $10        $10        $10
       A5               $A5        error      $A5
       (10)             $10        $0A        $0A
       (A5)             $A5        error      error
       01:2000          $012000    $0107D0    $012000
       $01:2000         $012000    $012000    $012000
       
    See also: ? (evaluate expression)

+ .basic       Dump BASIC table pointers

    Displays the addresses and sizes of BASIC tables.
    
      .basic
      
    See also: .basic_dumpline, .basic_vars, .basic_dumpstack,
              .basic_rebuildvnt, .basic_save

+ .basic_dumpline  Dump BASIC program line

    Lists the statements contained within a BASIC line.
    
      .basic_dumpline [<address> | * | 0] [-o <offset>] [-c]
      
    The optional address specifies the beginning of the line, including
    the line number. If no address is specified, the continuation address
    from the last command is used.

    Using * for the address uses the current line address (STMCUR). Zero
    specifies the beginning of the program (STMTAB).
    
    -o specifies an optional byte offset from the beginning of the line.
    Any token that begins that that byte offset is marked in the output
    with >>.

    -c gives continuous output until the end of the program.
    
    Tokens from Atari BASIC, BASIC XL, and BASIC XE are supported.
    
    See also: .basic, .basic_vars

+ .basic_dumpstack  Dump BASIC runtime stack

    Lists pending GOSUB and FOR..NEXT loops on the BASIC stack.
    
      .basic_dumpstack
      
    See also: .basic

+ .basic_rebuildvnt  Rebuild BASIC variable name table

    Reinitializes the BASIC variable name table (VNT) based on the variable
    value table (VVT).

      .basic_rebuildvnt

    Deletes all existing variable names and replaces them with new variable
    names, based on the variable type information in the VVT. This can repair
    a program with a damaged VNT, at the cost of losing any existing variable
    names. The statement table, array table, and runtime stack are relocated
    in the process.

    Using this command on a running BASIC program is likely to produce
    fireworks and is not recommended.

+ .basic_save  Save BASIC program

      .basic_save <path>

    Saves a BASIC program to a file on the host (not on the emulated disk).
    The file produced is the same format produced by Atari BASIC.

    A check is made during the save process for an abnormally large
    argument stack region, which is caused by Atari BASIC rev. B when saving.
    If detected, the argument stack region is corrected back to its normal
    size of 256 bytes.

    This command cannot be used with Basic XE when Extend mode is enabled.

+ .basic_vars  Dump BASIC variables

    Dumps the contents of the Atari BASIC variable name table (VNT).
    
      .basic_vars
      
    The token and name of each variable is displayed.

+ .batch       Run debugger batch script

    Runs the contents of a text file as a series of debugger commands.
    
      .batch <filename>

+ .beam        Show ANTIC scan position
+ .caslogdata  Toggle verbose cassette data read logging

+ .ciodevs     Dump Central Input/Output (CIO) device list

    Dumps the list of CIO devices in the HATABS database.
    
      .ciodevs

+ .covox       Dump Covox sound extension status

+ .diskdumpsec Dump floppy disk sector data

    Displays raw sector data.
    
      .diskdumpsec [-d <drive>] <virt-sector>
      
    Reads a raw sector from disk by virtual sector number and displays
    its contents. If phantom sectors are present, the first one is used.
    Dumping a sector does not disturb the drive's timing state.
    
    WARNING: While this command doesn't disturb timing state, it will
             change virtual disk image state when reading sectors off
             a drive with a mounted folder.
    
    See also: .diskorder (set forced phantom sector ordering),
              .disktrack (show sector order within track)

+ .diskorder   Set forced phantom sector ordering

    Overrides default phantom sector ordering with a predefined order.
    
      .diskorder <sector>               (Restore default sector ordering)
      .diskorder <sector> <indices...>  (Override sector ordering)
      
    By default, phantom sectors within a disk track are returned either
    by their storage order in the disk image (.pro format) or according
    to sector timing (.atx format). The .diskorder command allows the
    ordering to be overridden in order to diagnose or correct load
    failures due to incorrect sector order.
    
    Phantom sector indices start with 1 and correspond to the Nth physical
    sector within the disk image. This command causes virtual sector 43
    to load its four phantom sectors in stored order:
    
      .diskorder 43 1 2 3 4
      
    This command reverses the load order:
    
      .diskorder 43 4 3 2 1
      
    The DISK logging channel is useful for examining the sector load order
    initiated by a program.
    
    See also: lfe (enable log channel), lft (enable tagged log channel),
              .disktrack (show sector order within track)

+ .diskreadsec Read sector from floppy disk

    Reads a sector from floppy disk into memory.
    
      .diskreadsec [-d <drive>] <virt-sector> <address>
      
    Reads a raw sector from disk by virtual sector number and writes it
    into memory. If phantom sectors are present, the first one is used.
    Dumping a sector does not disturb the drive's timing state.
    
    WARNING: While this command doesn't disturb timing state, it will
             change virtual disk image state when reading sectors off
             a drive with a mounted folder.
    
    See also: .diskwritesec (write sector to floppy disk)

+ .disktrack   Show sector order within track

    Displays all sectors within a track on D1: in rotational order.
    
      .disktrack <track>
      
    The sectors are shown with their virtual sector number and phantom
    index, followed by the position of the sector in fractions of a
    rotation. For a standard drive at 288 RPM, there are about 4.8
    rotations per second.
    
    See also: .diskorder (set phantom sector ordering), 

+ .diskwritesec Read sector from floppy disk

    Writes a sector from memory to a floppy disk.
    
      .diskwritesec [-d <drive>] <virt-sector> <address>
      
    Writes memory to a raw sector from disk by virtual sector number.
    If phantom sectors are present, the first one is used.
    
    See also: .diskwritesec (write sector to floppy disk)

+ .dlhistory   Show ANTIC display list execution history

    Displays history of display list instructions executed by ANTIC.
    
      .dlhistory
      
    Unlike .dumpdlist, .dlhistory shows past display list history even if
    the display list has been modified in memory. It also shows some
    recorded information not found in the display list itself, such as the
    HSCROL, VSCROL, and DMACTL states when the display list instructions
    were executed.

+ .ds1305      Show DS1305 real-time clock status

    Displays status of the DS1305 real-time clock chip in the SIDE
    or Ultimate1MB hardware.
    
      .ds1305

+ .dma         Show current ANTIC DMA pattern

    Displays the pattern of DMA cycles performed by ANTIC for the current
    scan line.
    
      .dma
      
    The DMA pattern can change in the middle of the scan line depending
    on when certain critical cycles are passed and if any pertinent
    registers are rewritten. For instance, a mid-line write to DMACTL
    that changes the playfield width can change the DMA pattern.
    
    See also: .dmamap (show ANTIC DMA activity map)

+ .dmabuf      Show ANTIC DMA line buffer

    Displays the contents of the internal line buffer within ANTIC.
    
      .dmabuf
      
    See also: .dma (show current ANTIC DMA pattern)

+ .dmamap      Show ANTIC DMA activity map

    Displays the pattern of DMA cycles performed by ANTIC for the current
    frame.
    
      .dmamap
      
    ANTIC DMA analysis must be enabled in the View menu for this command to
    work, as otherwise DMA cycle patterns are not captured.
    
    Each line is of the form:
    
        8: .*......................~ ~..................... |  10:104
        
    The numbers at the end are DMA and non-DMA cycle counts, respectively.

    Unlike the .dma command, the .dmamap command always shows the exact DMA
    cycle pattern that occurred, complete with any mid-scanline changes.
    However, it cannot show upcoming DMA cycles like the .dma command can.
      
    See also: .dma (show current ANTIC DMA pattern)

+ .dumpdlist   Dump ANTIC display list

    Disassemble an ANTIC display list stored in memory.
    
      .dumpdlist [-n] [<address>]
      
    Options:
    
      -n    Do not collapse groups of identical mode lines.
      
    If no address is supplied, the current ANTIC display list pointer is
    used.

+ .dumpdsm     Dump disassembly to file

    Disassemble a range of memory as CPU instructions to a file.
    
      .dumpdsm [-c] [-l] [-p] [-n] [-s] [-t] <filename> <addr> L<length>
      
    The following options can be specified:
    
      -c    Include code bytes.
      -l    Use lowercase opcode names.
      -n    Do not decode labels.
      -p    Include PC address.
      -s    Separate routines with blank lines after jumps and returns.
      -t    Use 4 character tabs.

+ .dumpsnap    Create bootable snapshot image

    Create a bootable snapshot image from the current simulator state.
    
      .dumpsnap [-u] <path.atr>
      
    Options:
    
      -u    Disable compression and use uncompressed blocks
      
    Records hardware and memory state to a disk image with a loader that
    restores the state on boot. The snapshot image contains the base 64K
    of memory and requires a 128K system to boot (the extra memory is
    used by the loader). The loader attempts to reconfigure the hardware
    to match the snapshot state and then resume the running program.
    
    Not all state is restored precisely and load success depends on the
    exact state and program code. For best results, the same OS ROM
    should be used, no cartridge should be present, and the snapshot
    should be taken at the beginning of the NMI handler for the vertical
    blank interrupt.

+ .echo        Display message to console

    Writes a string to the console window.
    
      .echo <strings...>
      
    Quoted strings are displayed without quotes. To display a string with
    a quotation mark in it ("), use escaped string syntax. Escaped strings
    are quoted strings that are prefixed with \ and have \n, \", or \\
    escapes inside them.
    
    Example:
    
       .echo foo             prints: foo
       .echo foo  bar        prints: foo bar
       .echo "foo  bar"      prints: foo  bar
       .echo \"\"foo  bar\"" prints: "foo  bar"
       .echo \"x\ny"         prints: x
                                     y
                                     
    See also: .printf

+ .gtia        Display GTIA status

+ .ide         Display IDE emulator status

    Displays the current state of the emulated IDE device.
    
      .ide

+ .ide_dumpsec Dump IDE raw sector

    Dumps the contents of a raw IDE hard disk sector.
    
      .ide_dumpsec [-l] <lba>
      
    Reads a sector by linear block address (LBA) and displays the contents.
    This bypasses the ATA interface, so it can be done unobtrusively even if
    the emulated device is in reset state or in the middle of a command.
    
      -l    Dump only every other byte (16-bit mode on 8-bit bus).
      
    See also: .ide_rdsec, .ide_wrsec

+ .ide_rdsec   Read IDE sector into memory

    Reads an IDE sector into CPU memory.
    
      .ide_rdsec [-l] <lba> <address>
      
    Reads a sector by linear block address (LBA) into CPU memory. This
    bypasses the ATA interface, so it can be done unobtrusively even if the
    emulated device is in reset state or in the middle of a command. 512
    bytes are read by default, or 256 if -l is specified.

      -l    Read only every other byte (16-bit mode on 8-bit bus).
      
    See also: .ide_dumpsec, .ide_wrsec

+ .ide_wrsec   Write IDE sector from memory

    Writes an IDE sector from CPU memory.
    
      .ide_wrsec [-l] <lba> <address>
      
    Writes a sector by linear block address (LBA) from CPU memory. This
    bypasses the ATA interface, so it can be done unobtrusively even if the
    emulated device is in reset state or in the middle of a command. 512
    bytes are read by default, or 256 if -l is specified.

      -l    Write only every other byte (16-bit mode on 8-bit bus). The
            high byte is set to $FF.
      
    See also: .ide_dumpsec, .ide_wrsec

+ .iocb        Display CIO I/O control blocks

    Displays the contents of the nine IOCBs used by CIO.
    
      .iocb
      
    The zero-page IOCB, or ZIOCB, displayed as ZP. It is only valid during
    CIO operation.
    
    A device name including an ID and a tilde, e.g. $50~R:, is reported for
    a provisionally open IOCB. An IOCB is provisionally opened when the OS
    successfully receives a device response to a type 4 poll for a missing
    CIO device on the SIO bus. Further I/O to this IOCB with the HNDLOD
    variable set will trigger a load of the handler from the device into
    memory. The reported ID is the SIO address of the device to be used
    for handler loading.
    
    See also: .tracecio, .ciodevs

+ .loadksym    Load kernel symbols

    Loads kernel symbols for the original 10K OS.
    
      .loadksym <file>
      
    Loads a symbol file for a module at $D800-FFFF.

+ .loadobj     Load executable object

    Loads an executable object from a file.
    
      .loadobj <file>
      
    <file> must be an executable object in Atari DOS executable format.
    INITAD and RUNAD segments are skipped and no changes to execution state
    are made other than to load program segments into memory. This is
    intended to allow helper modules to be loaded into RAM.
    
    See also: .readmem, .writemem

+ .loadsym     Load module symbols

    Loads module symbols from a symbol file.
    
      .loadsym <file>
      
    Two types of symbols are supported. A labels file allows the debugger to
    match addresses to labels, while a listing file permits source-level
    debugging. Both label and listing files can be loaded at the same time,
    and multiple sets of symbols can also be loaded.

+ .map         Show memory map layers

    Displays memory layers active in the memory mapper
    
      .map
      
    This displays the memory layers that are being tracked internally in
    the emulator.

+ .netstat     Display network connection status

    Shows UDP/IP and TCP/IP connections on the emulated network.
    
      .netstat
      
    Displays a list of connections maintained by the gateway on the emulated
    network. This only applies if DragonCart emulation is active.
    
    Five columns are shown:
    
      Proto:
          Protocol for connection (TCP/UDP).
          
      Local address:
          Emulation-side address as seen by the gateway. This is typically
          the address provided by the program driving the DragonCart and
          will be on the emulation subnet.
          
      Foreign address:
          The other address of connection, either the gateway itself or an
          external host.
          
      State:
          TCP connection state
      
      NAT address:
          Host address used by NAT gateway for external connections. This
          is the address that the external server sees the connection from.

^ .onexeclear, .onexelist, .onexeload, .onexerun   Executable command triggers
> .onexeclear  Clear queued on-executable commands
> .onexelist   List queued on-executable commands
> .onexeload   Queue command on executable load
> .onexerun    Queue command on executable run

    Queue commands for when an executable loads or runs.
    
      .onexeclear          (Clear queued commands)
      .onexelist           (List queued commands)
      .onexeload <command> (Queue command prior to executable load)
      .onexerun <command>  (Queue command prior to executable run)
      
    This allows debugger commands to be automatically issued when
    an executable loads or runs. The on-load commands are issued
    before the first segment is loaded, while the on-run commands
    are issued before the run vector is activated. Commands are
    removed from the queue after they are run.
    
    The on-exe commands only trigger when an executable is loaded
    by the simulator itself. They do not activate when an executable
    is loaded by DOS, which is invisible to the simulator.

^ .pathdump, .pathrecord, .pathreset, .pathbreak   Manage execution path recording
> .pathdump    Dump disassembly of recorded paths to a file
> .pathrecord  Show or change path recording setting
> .pathreset   Clear recorded paths
> .pathbreak   Toggle break on new path

    Record and dump instruction paths executed by the CPU.

      .pathrecord [on|off] (Show or change path recording setting) 
      .pathreset           (Clear recorded paths)
      .pathdump <file>     (Dump path disassembly to a file)
      .pathbreak [on|off]  (Show or change new path break setting)
    
    Path recording, when enabled, marks the addresses of branch targets
    and subroutines during execution, making it easier to follow
    execution flow in a disassembly and identifying which memory areas
    are confirmed to contain code. When enabled, the diassembly will
    also show pseudo-labels for any addresses not already marked with
    a symbol.
    
    The .pathbreak command permits halting execution whenever a new
    path is encountered. This is handy for identifying the exit path
    in a large frame loop, as the body of the loop can be captured and
    then .pathbreak enabled to capture the exit path.

+ .pbi         Display Parallel Bus Interface (PBI) status
+ .pclink      Display PCLink status
+ .pia         Display Peripheral Interface Adapter (PIA) status 
+ .pokey       Display POKEY status

+ .printf      Display message with formatted fields

    Writes a string to the console window with formatted fields.
    
      .printf "format-string" [field...]

    Format-string can contain formatted fields like the C library
    function printf(). Formatting specifiers are of the form:
    
      %[flags][width][.precision][length]type

    Flags:
      
      0        Apply zero padding to right-justified string
      #        Prefix %x output with 0x and %X output with 0X
      +        Always display +/- sign on numbers
      <space>  Prefix positive numbers with a space
      -        Left-justify formatted field
      
    Width is a positive number specifying the minimum characters to
    display for the field. If the formatted field is shorter than
    the width, the field is padded according to flags, with right
    justification with spaces being the default.
    
    Precision is a non-negative number specifying minimum number of
    digits to display for numeric types. Zeroes are prepended to
    the number if it has fewer digits than the specified precision.
    
    Both width and precision may be specified as variable (*) in
    order to set them via separate expressions. If variable, the
    width and precision arguments come before the value argument,
    in that order. The values are clamped to avoid disasters.
    
    Length specifies the size of an integer field:
    
      hh       Byte (8-bit)
      h        Word (16-bit)
      l        Long (32-bit) (default)
    
    Type specifies the field type:
    
      %b       Binary number
      %c       ASCII character (only 20-7E; others produce '.')
      %d       Signed decimal
      %e       Decimal float by address, exponential notation
      %f       Decimal float by address, floating-point notation
      %g       Decimal float by address, general notation
      %i       Signed decimal (equivalent to %d)
      %s       ATASCII string buffer by address
      %u       Unsigned decimal
      %x       Hexadecimal (lowercase)
      %X       Hexadecimal (uppercase)
      %y       Symbol address

    Unlike the C function printf(), .printf always prints a newline
    after the formatted string. Also, note that %e/%f/%g require
    the address of a decimal float and not the value of a binary
    float.
    
    Example:
      .printf "Display list vector: $%04x" dw(vdslst)

    See also: .echo

+ .readmem     Read memory from disk

    Read a block of data from a file on disk into memory.

      .readmem <path> <xaddress> [L<length>]
      
    The address may use extended memory syntax, i.e. v:4000 for VBXE
    memory.
    
    See also: .loadobj

+ .reload      Reload symbol files

    Re-reads symbol files for all currently loaded symbols.
    
      .reload
      
    See also: lm (list modules), .loadsym, .unloadsym

+ .restart     Restart emulated system

    Performs a cold reset.
    
      .restart

+ .sdx_loadsyms  Load SpartaDOS X symbols

    Loads symbols from the SpartaDOS X symbol table.
    
      .sdx_loadsyms [address]
      
    By default, this follows the symbol chain starting with the pointer
    at address DOSVEC+$127. An alternate override address for the pointer
    can be specified. The loaded symbols are placed in a module called
    SDX. If this module exists, it is cleared before being reloaded.
    
    NOTE: This command can only see the full set of symbols if the SDX
    library is banked in. Otherwise, only resident symbols outside of
    the library bank will be seen. This isn't a problem during normal
    operation because the library bank has to be enabled for either
    symbol resolution or to call library functions.

+ .sio         Dump SIO device control block (DCB)

    Displays the contents of the SIO device control block.
    
      .sio [-b]
      
    The -b option gives one-line abbreviated output.

+ .sourcemode  Switch between source and disassembly level debugging

    Selects or displays the current source debugging mode.
    
      .sourcemode [on|off]
      
    The debugger can optionally jump to source code whenever appropriate
    symbols are available. By default, this happens only when single
    stepping or resuming execution from a source code window. By using
    the .sourcemode command and the -n option of the g (Go) command,
    however, you can force source mode debugging. This is most useful
    in scripts.
    
    See also: g (Go)

+ .sprintf     Construct message with formatted fields

    Constructs a string with formatted fields.
    
      .sprintf "format-string" [field...]

    Expands format tokens in the format-string with the supplied fields
    and stores it in the @ts variable. This variable can then be used
    by subsequent commands that take a text string, such as .printf,
    .sprintf, and bt.

    The format-string is the same format as that used by the .printf
    command.

    See also: .printf, bt

+ .sum         Compute sum of memory range

    Computes the sum of bytes in a memory range.
    
      .sum [-w] address L<length>
      
    All bytes within the memory range are added and both the binary sum
    and the one's complement (carry wraparound) sum are reported.
    
    If -w is specified, a sum of words is computed instead. The inverted
    and byte-swapped checksum is also reported for TCP/IP purposes.

+ .tape        Display cassette tape deck status

+ .tapedata    Display cassette tape data

    Displays data from the currently loaded cassette tape.
    
      .tapedata [-t] [-b <baud> [-d]] [-r <pos>] [-p <pos>]
      
      -t           Display bit transitions
      -b <baud>    Decode data at given baud rate
      -d           Display only decoded bytes
      -r <pos>     Decode at offset in milliseconds from current position
      -p <pos>     Decode at absolute position in milliseconds
      
    The .tapedata command displays the data near the current tape
    position. By default, the raw internally stored data bits are
    displayed at 4Kbaud. If the -t flag is specified, only the locations
    of transitions are displayed.
    
    The -b flag specifies byte decoding at a specified baud rate and
    causes the debugger to attempt to identify byte locations through
    start and stop bits. The -d flag causes only decoded bytes and not
    intermediate data bits to be displayed.
    
    The decoding algorithm is similar but not the same as that which
    actually occurs during simulation, which has an additional low pass
    filter on the serial input based on the serial rate. The debugger
    can also misdecode the initial bytes due to starting from ground
    state.
    
    See also: .tape

+ .tracecio    Toggle CIO call tracing
+ .traceser    Toggle serial I/O port tracing

+ .ultimate    Dump Ultimate1MB status

    Displays the state of the Ultimate1MB expansion hardware.
    
       .ultimate1mb
       
    See also: .ds1305

+ .unloadsym   Unload module symbols
+ .vbxe        Display VBXE status
+ .vbxe_bl     Display VBXE blit list (BL)
+ .vbxe_xdl    Display VBXE extended display list (XDL)
+ .vbxe_traceblits    Toggle VBXE blit tracing
+ .vectors     Display kernel vectors

+ .warmreset   Warm reset simulation

    Resets the simulation hardware (XL/XE) or triggers the System Reset
    button logic (400/800).
    
       .warmreset
       
    See also: .restart

+ .writemem    Write memory to disk

    Write a block of memory to a file on disk.

      .writemem <path> <xaddress> L<length>
      
    The address may use extended memory syntax, i.e. v:4000 for VBXE
    memory.

. 
. Some commands support extended memory syntax:
.   $0000      CPU view of primary memory
.   $01:0000   CPU view, 65C816 high memory
.   n:$0000    ANTIC view of primary memory
.   v:$00000   VBXE memory
.   r:$0000    Main memory
.   x:$00000   Extended memory
. 
. Some commands support length syntax:
.   db siov L100
.   db 4000 L>5FFF
.
. Use .help <command> for detailed help on that command.
