Version 0.7 alpha 1 - 19-Jan-2025:
 - Added support for hi-res graphics:
   - The GRAPHICS command is used to create and manipulate up to 256 hi-res
     surfaces with ids 0 - 255:
       GRAPHICS BUFFER id, width, height
         - Creates an off-screen buffer surface.
         - Note that surface 0 cannot be a buffer.
       GRAPHICS CLS id [, colour]
         - Clears a surface.
       GRAPHICS COPY src_id TO dst_id [, when] [, transparent]
         - Copies one surface to another (c.f. PAGE COPY on the CMM2).
       GRAPHICS DESTROY { id | ALL }
         - Destroys a surface.
       GRAPHICS INTERRUPT id, {interrupt|0}
         - Sets or clears the interrupt handler for a window surface.
       GRAPHICS LIST
         - Lists all surfaces.
       GRAPHICS SPRITE id, width, height
         - Creates a sprite surface.
         - Note that all graphics primitive commands can be used on sprite
           surfaces; this is different to other MMBasics.
         - Note that surface 0 cannot be a sprite.
       GRAPHICS TITLE id, title$
         - Sets the title of a window surface.
       GRAPHICS WINDOW id, width, height [, x] [, y] [, title$] [, scale]
                       [, interrupt]
         - Creates a window surface.
         - Note that surface 0 can (only) be a window.
       GRAPHICS WRITE { id | NONE }
         - Selects the surface to direct other graphics commands to
           (c.f. PAGE WRITE on the CMM2).

   - The following standard MMBasic graphics commands are implemented including
     supporting array parameters where appropriate:
       ARC x, y, r1, [r2], arcrad1, arcrad2 [, colour]
       BLIT x1, y1, x2, y2, width, height [, src_id] [, flags]
       BLIT CLOSE [#]id
       BLIT CLOSE ALL
       BLIT COMPRESSED address, x, y [, transparent]
       BLIT MEMORY address, x, y [, transparent]
       BLIT READ [#]dst_id, x, y, width, height [, src_id]
       BLIT WRITE [#]src_id, x, y [, orientation]
       BOX x, y, w, h [, lw] [, c] [, fill]
       CIRCLE x, y, radius [, line_width] [, aspect_ratio] [, colour] [, fill]
       CLS [colour]
         - Note that if there is no current graphics write surface then this
           will clear the console. To clear the console explicitly use the
           CLS CONSOLE or CONSOLE CLEAR commands.
       DEFINEFONT [#]font_id
       FONT [#]font_id [, scale]
       GUI BITMAP x, y, bits [, width] [, height] [, scale] [, fcolour] [, bcolour]
       IMAGE RESIZE_FAST x, y, width, height, new_x, new_y, new_width, new_height [, src_id]
                         [, flag]
       LINE x1, y1, x2, y2 [, width [, colour]]
       LINE GRAPH x(), y() [, colour]
       LINE PLOT ydata() [, nbr] [, xstart] [, xinc] [, ystart] [, yinc] [, colour]
       LOAD BMP file$ [, x] [, y]
       LOAD IMAGE file$ [, x] [, y]
       LOAD PNG file$ [, x] [, y] [, transparency_cut_off]
       PIXEL x, y [, colour]
       POLYGON n, x(), y() [, bordercolour] [, fillcolour]
       RBOX x, y, width, height [, radius] [, colour] [, fill]
       SPRITE CLOSE [#]id
       SPRITE CLOSE ALL
       SPRITE HIDE [#]id
       SPRITE INTERRUPT interrupt
       SPRITE HIDE ALL
       SPRITE HIDE SAFE [#]id
       SPRITE LOAD file$ [, start_sprite] [, colour_mode]
       SPRITE MOVE
       SPRITE NEXT [#]id, x, y
       SPRITE NOINTERRUPT
       SPRITE READ [#]id, x, y, w, h [, src_id]
       SPRITE RESTORE
       SPRITE SCROLL x, y [, colour]
       SPRITE SET TRANSPARENT rgb121_colour
       SPRITE SHOW [#]id, x, y, layer [, flags]
       SPRITE SHOW SAFE [#]id, x, y, layer [, flags] [, ontop]
       SPRITE WRITE [#]id, x, y [, flags]
       TEXT x, y, string$ [, alignment$] [, font] [, scale] [, fcolour] [, bcolour]
       TRIANGLE x1, y1, x2, y2, x3, y3 [, colour] [, fill]

   - The following standard MMBasic SPRITE functions are implemented:
       SPRITE(A, [#]id)
       SPRITE(C, [#]id [, m])
       SPRITE(D, [#]id1, [#]id2)
       SPRITE(E, [#]id)
       SPRITE(H, [#]id)
       SPRITE(L, [#]id)
       SPRITE(N [, layer])
       SPRITE(S)
       SPRITE(V, [#]id1, [#]id2)
       SPRITE(T, [#]id)
       SPRITE(W, [#]id)
       SPRITE(X, [#]id)
       SPRITE(Y, [#]id)

 - Added support for music and sound-fx playback.
   - The following standard MMBasic audio commands are supported:
       PLAY EFFECT file$ [, interrupt]
       PLAY FLAC file$ [, interrupt]
       PLAY MODFILE file$ [, sample_rate] [, interrupt]
       PLAY MODSAMPLE sample_num, channel_num [, volume] [, sample_rate]
       PLAY MP3 file$ [, interrupt]
       PLAY PAUSE
       PLAY PREVIOUS
       PLAY RESUME
       PLAY SOUND sound_no, channel_no, type [, frequency] [, volume]
       PLAY STOP
       PLAY TONE left [, right] [, duration] [, interrupt]
       PLAY VOLUME left [, right]
       PLAY WAV file$ [, interrupt]

 - Added support for up to 4 USB gamepads:
   - Commands:
       DEVICE GAMEPAD CLOSE id
       DEVICE GAMEPAD OPEN id [, interrupt] [, bitmask]
       DEVICE GAMEPAD VIBRATE id [, low_freq] [, high_freq] [, duration_ms]
       DEVICE GAMEPAD VIBRATE id OFF
   - Functions:
       DEVICE(GAMEPAD id, funct)
       MM.INFO$(GAMEPAD id)
         - Retrieves SDL mapping for gamepad.

 - Added OPTION SIMULATE to enable platform specific compatibility with other
   MMBasics.
     OPTION SIMULATE device$
       - device$ is one of "Colour Maximite 2", "Game*Mite", "PicoMiteVGA",
         "MMBasic for Windows" or "MMB4L" to return to default behaviour.
   - Causes MM.DEVICE$, MM.INFO$(DEVICE) and MM.INFO$(PLATFORM) to return
     the appropriate simulated value.
   - If required MM.INFO$(DEVICE X) can be used to retrieve the real device
     name; this relies on the lenient error checking currently exhibited by
     other MMBasic platforms not reporting the "extraneous" X as a syntax
     error.

     Colour Maximite 2:
       - Simulates USB controllers 1-3 being read as if they were Wii Classic
         controllers attached to I2C channels 1-3:
         - USB1 = I2C3, USB2 = I2C1, USB1 = I2C2.
       - Commands:
           CONTROLLER CLASSIC CLOSE [i2c]
           CONTROLLER CLASSIC OPEN [i2c] [, interrupt] [, bitmask]
           MODE, PAGE COPY, PAGE SCROLL, PAGE WRITE
       - Functions:
           CLASSIC({B | LX | LY | RX | RY | L | R | T} [, i2c])

     Game*Mite (RP2040):
       - Simulates sufficient GPIO to support USB controller 1 being read
         using SETPIN and PORT() as if it were the 8-button Game*Mite
         controller.
       - Commands:
           FRAMEBUFFER, BLIT FRAMEBUFFER, FLASH DISK LOAD, SETPIN
       - Functions:
           MM.INFO(CPUSPEED), MM.INFO(DRIVE), MM.INFO(FLASH ADDRESS),
           MM.INFO(PINNO GPxx), PORT()

     MMBasic for Windows:
       - As "Colour Maximite 2" except supports a single USB controller being
         read with the GAMEPAD command and function.

     PicoMiteVGA (RP2040):
       - Simulates sufficient GPIO to support USB controllers 1 & 2 being
         read using PIN, PULSE and SETPIN as if they were 12-button SNES
         controllers wired according to the PicoGAME VGA 2.0 schematic.
       - Commands:
           FRAMEBUFFER, BLIT FRAMEBUFFER, FLASH DISK LOAD, MODE, PIN,
           PULSE, SETPIN
       - Functions:
           MM.INFO(CPUSPEED), MM.INFO(DRIVE), MMM.INFO(FLASH ADDRESS),
           MM.INFO(PINNO GPxx), PIN()
       - Note that MODE 1 coloured tiles are not currently supported.

   Added other commands:
       ON PS2 {interrupt | 0}
         - As per PicoMite.
       OPTION ANGLE {DEGREES | RADIANS}
         - As per PicoMite.
       OPTION AUDIO {ON | OFF}
         - Persistent option to enable/disable audio.
         - Default ON.
         - The intended purpose of this OPTION is to allow MMB4L to be
           easily run on Linux devices (in particular Docker containers)
           where the SDL audio is too difficult for the user to be bothered to
           configure ;-).
         - Note that when OFF all the underlying audio boilerplate is still
           executed except for the bit that makes the noise and the calling of
           audio interrupts.
       OPTION AUTOSCALE {ON | OFF}
         - Persistent option to enable/disable automatic scaling of windows when
           using OPTION SIMULATE.
         - Default ON.
         - When ON the window for the simulated device will be scaled up (in
           whole number multipliers) to be the largest that will fit on the
           display.
       SETENV name$ = value$
         - Synonym for existing SYSTEM SETENV.
         - Note that the value may also be an integer array containing a
           LONGSTRING.

   Added other functions:
       ATAN2(y, x)
       KEYDOWN(n)
       MM.INFO(PS2)

 - Added CONSOLE TITLE command as preferred synonym for CONSOLE SETTITLE so
   as to match the GRAPHICS TITLE command.

 - Added optional parameter to MM.INFO$(ERRMSG [errno%]) so it can now be used
   to retrieve the default message for any given 'errno%' as well as the
   current error message (when errno% is not specified).
   - Note that currently error numbers are not stable between MMB4L releases.

 - Changed DATE$(), DATETIME$(), DAY$() and TIME$() to be consistent with other
   MMBasics that do not have timezone support whilst returning local timezone
   values where most appropriate:
     TIME$()          - returns current time in local timezone.
     DATE$()          - returns current date in local timezone.
     DATETIME$(NOW)   - returns current date/time in local timezone.
     DATETIME$(epoch) - returns date/time in UTC.
     DAY$(NOW)        - returns current day in local timezone.
     DAY$(epoch)      - returns day in UTC.
   Additionally:
     EPOCH(datetme$)  - assumes the date/time is in UTC.

 - Changed MATH(SD a()) function to use "Sample Standard Deviation Formula"
   instead of "Population Standard Deviation Formula".
   - This matches PicoMite MMBasic v6.0.0.

 - Changed SORT to allow bit 2 of the 'flags' to be set when sorting strings so
   that empty strings are considered to have the "biggest" value.
   - This matches PicoMite MMBasic v0.6.0

 - Fixed bug where ANSI control codes for setting the terminal title, showing
   the cursor, and resetting graphics styles and colours were written to
   STDOUT even when running without the MMBasic prompt.

Usage: gpioset [OPTIONS] <chip name/number> <offset1>=<value1> <offset2>=<value2> ...

Set GPIO line values of a GPIO chip and maintain the state until the process exits

Options:
 -h, --help: display this message and exit
 -v, --version: display the version and exit
 -l, --active-low: set the line active state to low
 -B, --bias=[as-is|disable|pull-down|pull-up] (defaults to 'as-is'):
set the line bias
 -D, --drive=[push-pull|open-drain|open-source] (defaults to 'push-pull'):
set the line drive mode
 -m, --mode=[exit|wait|time|signal] (defaults to 'exit'):
tell the program what to do after setting values
 -s, --sec=SEC: specify the number of seconds to wait (only valid for --mode=time)
 -u, --usec=USEC: specify the number of microseconds to wait (only valid for --mode=time)
 -b, --background: after setting values: detach from the controlling terminal

Biases:
 as-is: leave bias unchanged
 disable: disable bias
 pull-up: enable pull-up
 pull-down: enable pull-down

Drives:
 push-pull: drive the line both high and low
 open-drain: drive the line low or go high impedance
 open-source: drive the line high or go high impedance

Modes:
 exit: set values and exit immediately
 wait: set values and wait for user to press ENTER
 time: set values and sleep for a specified amount of time
 signal: set values and wait for SIGINT or SIGTERM

Note: the state of a GPIO line controlled over the character device reverts to default
when the last process referencing the file descriptor representing the device file exits.
This means that it's wrong to run gpioset, have it exit and expect the line to continue
being driven high or low. It may happen if given pin is floating but it must be interpreted
as undefined behavior.

SYSTEM "xclock & echo $! > my_pid.txt"

SYSTEM "xclock & echo $!", output$

ps -axuww | grep -e pulse -e wire