[Coco] format memory (was) Gotek floppy emulator

[Christopher R. Hawks]

On Tue, 16 Feb 2016 17:04:21 -0500
Gene Heskett <gheskett at wdtv.com> wrote:

> On Tuesday 16 February 2016 15:25:53 Tormod Volden wrote:
> 
> > On Tue, Feb 16, 2016 at 1:25 PM, Gene Heskett wrote:
> > > On Monday 15 February 2016 20:29:02 Bill Pierce via Coco wrote:
> > >>  Gene, on both my emulator and real Coco, smap shows 11k free.
> > >> As I said, I can format from the cmd line, but not from within
> > >> something else like the boot script from the ditro disks.
> > >>
> > >> One thing I've noticed is that 3.3.0 does not like older drivers.
> > >> It fares better with drivers built from the same build. Are all
> > >> your drivers in the 3.3.0 boot current? Or did you use some of
> > >> your older custom drivers? I even formatted my 4 gig partions on
> > >> my Glenside IDE with with my current boot.
> > >
> > > I did go down & play. I also have 11k free but its fragmented.
> >
> > Dear OS-9 experts, please bear with me and my lack of deep Level2
> > understanding, I am in the need for a long Q&A session on this. I
> > have read the "OS-9 system programmer's manual" from Microware
> > which is the best piece on OS-9 internals that I have found. Are
> > there other good texts, apart from reading the "source" code?
> > "Source" in quotes, because a lot of it is half-commented
> > disassembly of binaries :p
> >
> > OK, so you have 11k free. I suppose this is system memory (limited
> > to 64KB), whereas programs can use their own 64KB user memory
> > mapped in from the big pool (512KB to 2MB).
> >
> > > Format needs $2b70 worth of memory for its data, or 11,120 bytes.
> >
> > Format needs 11120 bytes of user memory, right? This is the data
> > segment pointed to by U upon execution of the module, in the
> > process' own memory space.
> >
> > I can well imagine that formatting a disk requires some system
> > memory as well (for buffers etc used during system call) - and this
> > is maybe the reason it goes south for you - but the 11120 bytes for
> > format and the 11k free system RAM cannot be directly compared,
> > right?
> >
> > I would be interested in knowing why format needs 11120 bytes (user
> > memory) for doing what it does, and whether this can be reduced. But
> > that is probably not very useful, since we can assume people should
> > have that much of free /user/ memory when doing such tasks.
> >
> > The more interesting question is whether format can be made to
> > consume less system memory. There is no F$ system memory requests
> > in the source, only innocent I/O calls from what I can see.
> >
> > Off-topic question: Why is allocation bit map routines (F$AllBit and
> > friends) system calls at all? They only operate on user memory,
> > right?
> >
> > BTW, I just tried out format on my Level1 Dragon formatting a
> > DriveWire drive, and it worked fine. It is the exact same binary as
> > on Level2 systems (6809 and 6309 versions are identical too, CRC
> > 0ABD19 in 3.3.0).
> >
> > Regards,
> > Tormod
> 
> Those are questions I may not have a qualified answer for until I can
> get rid of my startup file being locked forever, Tormod.  I wish I
> did, thats for sure.
> 
> Cheers, Gene Heskett

Gene:

    If you hold the space bar at boot, startup will not be run.


Christopher R. Hawks
HAWKSoft
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