The SWITCH command on the X68000

The SWITCH program is an important part of the Human68k operating system, especially as it's necessary to set the amount of memory installed in the machine. So here is a description of the different options available.


To start SWITCH, simply enter SWITCH at the command line. Provided the program is present and the PATH is set correctly (which should be the case if booting from system disks), the SWITCH program will open.

Using SWITCH is straightforward. On the left is a list of the system variables which can be changed by the user. To the right of each is the current setting, and to the right of the current setting is the list of available settings.

To change a variable, simply select it with the arrow keys and press Return. Each setting can then be varied using the up and down arrow keys. To exit the program and save changes, select the bottom option (終了), and a dialog will appear. Press Y to exit and save changes, N to exit and NOT save the changes, and ESC to cancel and continue using the program.


Let’s look at each variable in turn.


RS232C – This option allows the user to change the settings of the external RS232 ports on the system, and as such, peforms the same function as the SPEED program. From left to right, the port settings are: baud rate – number of data bits – parity – stop bits – flow control.
Baud rate: options are 19200 baud, 9600 baud, 4800 baud, 2400 baud, 1200 baud, 600 baud, 300 baud, 150 baud, 75 baud
Data bits: options are 8, 7, 6, or 5 bits
Parity: can be either odd (奇数), even (偶数) or none (なし)
Stop bits: can be either 1, 1.5 or 2
Flow control: options are Xon (XON/XOFF), Rts (RTS/CTS) or None


MEMORY – The most important variable of all. As the X68000 does not automatically detect the amount of RAM that is available, it is necessary to set it here manually. The minimum amount of RAM is 1MB; the maximum, 12MB.


BOOT – The user can choose how the system will boot when turned on or reset.
STD: the default. When STD is set, the machine will search for a bootable drive in the following order: Floppy Drive 0, Floppy Drive 1, other floppy drives… SCSI device 0, SCSI device 1 and so on.
SCSI0 – SCSI7: The machine will boot from the selected SCSI device.
2HD0 – 2HD3: The machine will boot from the selected floppy drive.
RAM/ROM: The machine will boot from the selected RAM or ROM area.


EJECT – Tells the machine whether or not to eject the floppy disks when the machine is switched off.
ON – Disks are ejected
OFF – Disks are not ejected


OPT2KEY – This setting determines when the monitor can be controlled using the OPT.2 key or not.
TVCTRL – Television control is possible
NORMAL – Television control is not possible


CONTRAST – Controls the level of contrast of the monitor. The higher the number the greater the contrast.


KANA – Determines whether kana input will be use the JIS standard or the AIU standard.


TV_CTRL – Determines whether the monitor is switched off as a result of the X68000 being switched off.
TV – The monitor stays on if the machine is switched off.
OFF – The monitor is switched off if the machine is switched off.


LCD_MODE – allows the display of seven-segment LCD style characters when using calculator mode (started by pressing the OPT.1 and OPT.2 keys together)
NORMAL – The monitor displays characters normally
LCD – The monitors uses seven-segment characters


SRAM – Determines how static RAM should be employed on the machine
NO_USE – Static RAM is not used
RAMDISK – Static RAM is used as a RAM disk. This option requires that the SRAMDISK.SYS device driver be loaded.
PROGRAM – Static RAM is available to programs to use.


P0 to P8 – these values set the colours to be used for the text palette. The Red, Green and Blue values have 32 possible values each


XCHG – Determines the appearance of the yen sign, overscore and pipe characters.
0: ‘￥’ is displayed as ‘￥’,      ‘ ¯ ’as ‘ ¯ ’,    and ‘ | ’ as ‘ | ’
1: ‘￥’ is displayed as ‘\’,        ‘ ¯ ’as ‘ ¯ ’ ,   and ‘ | ’ as ‘ | ’
2: ‘￥’ is displayed as ‘￥’,      ‘ ¯ ’as ‘ ~ ’,    and ‘ | ’ as ‘ | ’
3: ‘￥’ is displayed as ‘\’,        ‘ ¯ ’as ‘ ~ ’,    and ‘ | ’ as ‘ | ’
4: ‘￥’ is displayed as ‘￥’,      ‘ ¯ ’as ‘ ¯ ’,    and ‘ | ’ as ‘ ¦ ’
5: ‘￥’ is displayed as ‘\’,        ‘ ¯ ’as ‘ ¯ ’,    and ‘ | ’ as ‘ ¦ ’
6: ‘￥’ is displayed as ‘￥’,      ‘ ¯ ’as ‘ ~ ’,    and ‘ | ’ as ‘ ¦ ’
7: ‘￥’ is displayed as ‘\’,        ‘ ¯ ’as ‘ ~ ’,    and ‘ | ’ as ‘ ¦ ’


HD_MAX – Sets the number of hard disks attached to the machine. This is not user-definable, it's set by the machine (as far as I can tell)


WAIT_PRN – sets how long the machine should allow the printer to respond before a timeout is declared, the value specified being the number of seconds the machine should wait


FIRST_KY – Specifies how long the delay should be after a key is pressed and held before the machine begins to repeat the character.


NEXT_KEY – when the machine is auto-repeating a key currently being held down, NEXT_KEY specifies how much of a delay the machine should wait before repeating that key


SCSI_ID – The SCSI ID of the machine is set in the factory and shouldn’t be changed