MiSTer

MiSTer is an FPGA platform for which a lot of retro computer cores, including the Sinclair QL, exist. Unfortunately the QL is not as popular as other platforms so the core is still only a pretty basic port of the MiST board.

So in late 2018 I improved the core in several ways:

  • Switched the 68k core to the fx68k CPU core, which perfectly models a 68000 (though not a 68008, so still not perfect for a QL)
  • The different bus of the fx68k allows QL-SD to run correctly with all CPU speeds
  • I implemented a “MiSTer Gold Card”, which is more or less a SuperGoldCard with a 68000 (and minus floppy controller and stuff). For this I created a special MiSTer Gold Card boot ROM, which is integrated into the core.
  • The MiSTer Gold Card allows booting of (a special) SMSQ/E!
  • I implemented a special memory speed controller that emulates the memory contention of a real QL in order to try to match the original speed. Activated when CPU speed “QL” is selected.

In the end I even tried to implement an Aurora graphics card, which worked most of the time but never got stable enough to actually release, at which point I stopped because of other projects. A few weeks ago in late 2019 I resurrected the code and transplanted it onto the latest MiSTer framework. The plan is to integrate it into the main MiSTer distribution, but until then, enjoy it here:

MiSTer_20200101_patch.zip Patched main MiSTer executable. Only adds one missing key, not necessarily needed (if you don’t miss the key, that is)
MiSTer_QL_20200108.zip
MiSTer_QL_20200113.zip
MiSTer_QL_20200116.zip
My QL core
Added support for SDRAM v2 board
Allow mounting .WIN on main SD (needs qlsd108 driver below)
qlsd108_bin.zipUse the “Minerva_1.98a1_qlsd108.bin” file from this as MiSTer’s boot.rom
qlsd_win_demo.zip The QL-SD demo also works fine with MiSTer. See below for details how to use.
smsq_mister.zipSMSQ/E for the MiSTer. Must be copied onto a QXL.WIN and LRESPRed

Accessing .WIN files

Previously the QL core only accepted the same SD cards as the original QL-SD and this card must be in the secondary SD slot on the I/O expansion board. The card preferably must be freshly formatted (to avoid fragmentation) using FAT32 and then the .WIN file copied onto it.

The latest core now offers support for virtual SD images on the main MiSTer card, so the I/O board is not strictly needed anymore. But as images are more difficult to handle on the PC I have changed the QL-SD driver (now v1.08) to accept a .WIN file directly as the image. So you can now mount any .WIN file using the MiSTer menu and it will be available as “win1_” for the QL. Press backspace while in the mounting menu to unmount the file.

When a virtual image is mounted the SD slot on the I/O board is still available, but it is remapped to “win2_”.

Optionally by renaming the .WIN file to boot.vhd in the QL directory (or QL.vhd in the main directory) it will be mounted automatically on boot.