If a Markdown document contains an embedded machine that specifies a version number (eg, "1.15.6"), then the web server will switch to serving a compiled version, since that's the only way it can guarantee the requested version
I spent some time fixing the latter because browsers have started warning that synchronous XMLHttpRequest calls on the "main thread" (as Firefox calls it) are deprecated. Since the days of such calls seems to be numbered, I decided to act sooner rather than later. All PCjs XMLHttpRequests go through a single library function (weblib.loadResource), which accepts an fAsync parameter, and the only code that is still allowed to pass false for that parameter are "emergency" shutdown requests (which I believe browsers must still allow).
What this means is that XDF disk images formatted as 80-track 23-sector-per-track images will work with XDF code that honors that format; however, I've not yet been able to test with "real" XDF disk images (ie, disk images created with DiskDump using the experimental --xdf flag). "Real" XDF disk images almost certainly need more work (eg, setting all the sector IDs properly), but the groundwork has been laid.
Without --xdf, DiskDump simply dumps an XDF disk image as a vanilla 80-track, 23-sectors-per-track disk image.
In addition, I regenerated all the PC-DOS 7.00 disk images without --xdf, to see if that works any better (it seems to work for VirtualBox)
The padding attributes on the machine element (padtop, padbottom, etc) affect padding *around* the machine, whereas padding attributes inside the machine's style attribute affect padding *inside* the machine
However, performance will suffer until I can implement RTC interrupts;
also, there may be a problem exposed by the BIOS memory test following a soft reset