Interesting. It would be nice if a working A680 drive image turned up! Some thoughts:They've confirmed that the A680 drive format isn't typical. To the point that SCSIDM can't recognise/do anything with it. They were built from the "shoebox" - an external SCSI drive that hooked up to the A680 and built the entire image on the internal drive.
- The example of "boot sc0(0,0)vmunix" given by UnixCLI, if this is a block offset, suggests that there is no partition table (disklabel) at the start of the disk (as well as no Filecore partition). But then how is the length of the root partition and the offset of the swap partition identified? Apparently early 4.3 BSD systems had no disklabel and the offsets were compiled into the driver, then disklabel appeared in around 1988. Did iX always support disklabels, or did this come later with the R140? What if you create a disk image with no Filecore partition and no BSD partition table, hence with a zero offset to root (just skip the unwanted bits when writing the existing image to disk).
- How are the boot parameters passed to vmunix? Presumably in memory somewhere, but does UnixCLI (or RISCiXFS) always pass these, either from the CMOS defaults or from the user input, rather than vmunix reading CMOS for the defaults? Does UnixCLI convert a block offset into a partition number? (Can you configure CMOS with a block offset?)
- "Swap device cannot be root device" comes from machdep.o (and is a bit ambiguous) whereas "cannot mount root" comes from vfs.o - might be worth disassembling these to see what they're trying to do.
- This screenshot shows that when the A680 boots vmunix from sc0, it doesn't display anything previously to identify the interface as being present - unlike st, sd or et, which all are shown if present.
- Does anybody have a copy of the Acorn Technical Publishing System User Guide or the Acorn Technical Publishing System Programmer's Reference Manual?
- This is truly a wonderful picture, unfortunately not signed by the artist:
Statistics: Posted by timw — Sat Feb 08, 2025 9:23 pm