When MSX standard was expanded, it became common standard to enable/disable features by holding down keys during MSX boot process. Here are listed some of the effects that you may expect:
| KEY | HANDLER | EFFECT | NOTES |
|---|---|---|---|
| [0] | Nextor Disk-ROM | Disable permanent disk emulation mode (boot on .emu image) by deleting the emulation data file pointer from the partition table. | |
| [1] | Disk-ROM v2.30~ | Force starting in MSX-DOS1 mode, switches CPU to Z80 mode on turbo-R. | Also Nextor Disk-ROM |
| [2] | Nextor Disk-ROM | Force starting in MSX-DOS1 mode, switches CPU to R800-ROM mode on turbo-R. | |
| [3] | Nextor Disk-ROM | Boot directly to BASIC prompt (without execute AUTOEXEC.BAS). | |
| [4] | Nextor Disk-ROM | Boot in R800-ROM mode, assign the largest mapper found as the primary mapper. | MSX turbo R only |
| [5] | Nextor Disk-ROM | Assign only one drive to each Nextor kernel with a device-based driver regardless of the number of devices controlled by the driver. | |
| [A] | Nextor Disk-ROM | Prevent installation of Nextor Disk-ROM when inserted in primary slot 2 or secondary slot 2-0. | |
| [B] | MSXDOS2.SYS v2.40 | Boot directly to BASIC | |
| [C] | Nextor Disk-ROM | Prevent installation of Nextor Disk-ROM when inserted in secondary slot 3-2. | |
| [D] | Nextor Disk-ROM | Prevent installation of Nextor Disk-ROM when inserted in secondary slot 2-2. | |
| [E] | Nextor Disk-ROM | Prevent installation of Nextor Disk-ROM when inserted in secondary slot 1-2. | |
| [F] | MegaFlashROM | Prevent its installation when inserted in slot 2. | |
| [F] | Nextor Disk-ROM | Prevent installation of Nextor Disk-ROM when inserted in secondary slot 2-3. | |
| [H] | Custom MSX2/MSX2+ machines | This is used to reverse default 50/60Hz selection | |
| [N] | Nextor Disk-ROM | Prevent installation of Nextor Disk-ROMs. | |
| [R] | MegaFlashROM | Prevent its installation when inserted in slot 1. | |
| [R] | SVI-2000C | Start ROGO | "NYYRIKKI version" |
| [R] | Nextor Disk-ROM | Prevent installation of Nextor Disk-ROM when inserted in secondary slot 1-3. | |
| [S] | Nextor Disk-ROM | Prevent installation of Nextor Disk-ROM when inserted in secondary slot 2-1. | |
| [Q] | Nextor Disk-ROM | Prevent installation of Nextor Disk-ROM when inserted in primary slot 1 or secondary slot 1-0. | |
| [V] | Nextor Disk-ROM | Prevent installation of Nextor Disk-ROM when inserted in secondary slot 3-3. | |
| [W] | Nextor Disk-ROM | Prevent installation of Nextor Disk-ROM when inserted in secondary slot 1-1. | |
| [X] | Nextor Disk-ROM | Prevent installation of Nextor Disk-ROM when inserted in secondary slot 3-1. | |
| [Z] | Nextor Disk-ROM | Prevent installation of Nextor Disk-ROM when inserted in primary slot 3 or secondary slot 3-0. | |
| [CTRL] | Disk-ROM | Disable phantom drives (e.g. use only physical drives) | Without CTRL, 2 physical drives are handled. If second drives is not connected physical drive 1 is used instead of the second for copy. |
| [CTRL] | Arabic support ROM | Skips Arabic language support | On all Arabic Sakhr MSXs + Arabic Almithali (Perfect 1 & 2) |
| [CTRL] | SVI-2000C | Start ROGO | "gdx version" |
| [DEL] | Panasonic FS-A1/A1mk2 Firmware | Skip Desk-Pac software booting | Probably works for other Panasonic machines as well |
| [DEL] | Sony HB-F1/HB-F1II Firmware | Skip Personal databank software booting | |
| [DEL] | Sunrise IDE BIOS | Skip booting from the IDE device | |
| [DOWN] | GR8NET | Cancels re-initialisation of the adapter into target mapper configuration during the cold boot. GR8NET will be forced to continue with mapper mode 0. Useful for firmware update which must be performed in mapper 0 only. | |
| [ENTER] | GR8NET | Disable TCP/IP UNAPI | |
| [ESC] | GR8NET | Skip start-up delay after adapter finishes initialisation | |
| [ESC] | MegaFlashROM | Skip starting of ROM-image in flash | Default key can be changed by user. |
| [ESC] | Phillips NMS-1205 | Skip internal software | Custom software updates have many times reversed this effect. |
| [ESC] | Panasonic FS-A1GT | Clear RTC memory | |
| [F1] | GR8NET | Forcefully reload RAM disk image even if valid image is detected in RAM, Disk-ROM must be enabled (by simultaneous pressing of F4 key) | |
| [F2] | GR8NET | Invoke browser to load RAM disk image, Disk-ROM must be enabled (by simultaneous pressing of F4 key) | |
| [F3] | Carnivore 2 | Default UI settings | |
| [F3] | GR8NET | Disable build-in Disk-ROM | |
| [F4] | Carnivore 2 | Cancel auto-start | |
| [F4] | GR8NET | Enable built-in Disk-ROM | |
| [F5] | Carnivore 2 | Skip Boot menu | |
| [F5] | GR8NET | Forcefully disable GR8cloud device for Nextor (mapper modes 8-14) | |
| [GRAPH] | Novaxis SCSI BIOS | Skip the Novaxis SCSI BIOS | Gouda SCSI interface |
| [GRAPH]+[STOP] | SUB-ROM | Skip password prompt | MSX2 and up |
| [SELECT] | Game loaders | This is used to force to 50/60Hz mode | Common habit of cracked games |
| [SELECT] | GR8NET | Forcefully disable SD-card device for Nextor (mapper modes 8-14) | |
| [SHIFT] | Disk-ROM | Skip initialization of Disk ROM | |
| [TAB] | GR8NET | Invoke boot-up menu | |
| [UP] | MegaFlashROM | Enter recovery menu | |
| [UP] | GR8NET | Must be pressed before GR8NET starts initialisation and disabled GR8NET ROM completely, while engine is still active. Useful if GR8NET has ROM corrupt or ROM does not start or complete properly |