While playing around with the Next's QL Core I managed to mess something up, and rather than debug it in the moment I decided to just create a fresh OS card that I could keep working on.

This got me wondering what's actually needed, amongst all the software that comprises NextZXOS, to actually boot a usable system, and whether I could make a card that would boot the QL core automatically.

If you do want to use the process to make a card for the QL core, copy QXL.WIN to the card immediately after formatting it, then follow the rest of the instructions.

Note that there isn't really a practical argument for doing this - any SD card you have to hand in 2025 is cavernously large by 1982 standards and there's no reason to not just drop the entire NextZXOS distribution onto it.

It is, however, interesting to see how the boot process works.

After the main core starts, it attempts to load the firmware - TBBLUE.FW from the SD card. It then loads the configuration from files in machines/nextzxos/ - config.ini, menu.ini, and menu.def.

MENU.DEF contains the default list of personalities and can be overridden by a menu.ini in the same format.

At this stage the keymap is also loaded from machines/next/keymap.bin

The first line of menu.def tells us the next files we need:

menu=ZX Spectrum Next (standard),2,8,enNextZX.rom,enNxtmmc.rom,enNextMF.rom

enNextZX.rom contains the main operating system and BASIC, enNxtmmc.rom contains the disk operating system for the SD card, and enNextMF.rom contains the 'multiface' firmware that is invoked when the yellow NMI button is pressed.

Two more files are loaded after the system boots:

machines/next/enAltZX.rom nextzxos/enSystem.sys

This brings us to the familiar NextZXOS menu.

To make the Next launch the QL core automatically from here, we need to add a couple of more things to the card:

The entire contents of machines/ql:

machines/ql/

machines/ql/core.bit

machines/ql/core.cfg

machines/ql/core2.bit

machines/ql/greek.rom

machines/ql/Instructions.txt

machines/ql/js.rom

machines/ql/min198a1.rom

machines/ql/qlsdn.rom

and the .CORE command:

dot/CORE

Boot the machine, and to make sure it works, enter the Command Line and type .CORE ql - the machine should reboot into the QL core.

Cycle the power to get back into NextZXOS, use the browser to navigate to /nextzxos, hit BREAK and return to the command line.

type 10 .CORE ql followed by SAVE "AUTOEXEC.BAS" LINE 10

type RUN to return to the QL core. In future when the machine is powered on with this card present it will briefly enter NextZXOS, then boot the QL core automatically.