[Coco] Nitros Partitioning Was: CoCo SDC and others

[Brett Gordon]

Yup,  maybe an even lighter weight approach would be to (at build time) set
the wps/ofs of /dd and friends to something other than zero...for the
cocoFpga build.

brett
On Mar 8, 2017 11:22 AM, "Tim Fadden" <t.fadden at cox.net> wrote:

> On 3/8/2017 8:56 AM, Brett Gordon wrote:
>
>> Nitros is awesomely flexible unto itself.  It needs a little help with
>> sharing the hd though.
>>
>> Gene: how about lsn 1?  MBR likes the last half (or so) of that sector.
>> My
>> ccpt and taylor's partitioning want all of sector 0.  The last half of
>> sector zero is not really helpful.
>>
>> We dont have to make nitros read and apply the table.  Lets just add an
>> offset to each sector access in the fpga's sd driver.  We'll trick nitros
>> into beleiving sector 256 is actually sector 0 :)  This platform will
>> greatly benefit from this change.  And its such a bloody simple change. I
>> can/will do the work and sumbit the work to Tormod.  he, justly so, takes
>> heed of the list's input, so lets have a good discussion about it!
>>
>> I'm not asking nitros to actually read, write, or apply the table to it's
>> descriptors.  Thats a bigger project, as boisy's superdriver could be used
>> to apply this.   Or the boot/init code could call a module to noodle with
>> wps/ofs of matching descriptors.
>>
>> "OSes of the CoCo Unite!  Throw off the chains of os9 oppression!  Let the
>> people seize control of their own equipment.  Let there be partitioning!"
>> - Comrade Tyranous, the Red ( blue, and green) Leader of the People.
>>
>> ;)  cheers!
>>
>> brett
>> On Mar 8, 2017 7:38 AM, "Gene Heskett" <gheskett at shentel.net> wrote:
>>
>> On Wednesday 08 March 2017 01:34:04 Brett Gordon wrote:
>>
>> On Mar 7, 2017 7:52 PM, "Ron Klein" <ron at kdomain.org> wrote:
>>>
>>>> If you decide to use YA-DOS with the CoCo3FPGA, you will need to
>>>> flash it to the same bank that you use for Brett's NitrOS9 SD
>>>> loader.  That flash slot on the CoCo3FPGA is reserved for alternate
>>>> DOS's and can accommodate 16K roms like YA-DOS.  I'm not sure how
>>>> the NitrOS9 SD boot loader works, but perhaps we can see if Brett is
>>>> able to incorporate that boot loader into YA-DOS for those using a
>>>> CoCo3FPGA.
>>>>
>>> Yeah, the ROM-able nitros boot loader will have to be replaced with
>>> ya-dos.  But no worries: There's a decb loadable .bin file in the
>>> nitros9 repo that'll load up nitros too.  I think invoking 'make' just
>>> right will pop out a .dsk file.  Just get that image copied over.
>>> Yados can copy the dsk from DW to the SD card.
>>>
>>> Nitros has no partitioning.  That needs to change.  Maybe we can just
>>> hack a offset into Gary's nitros drivers, and force nitros to skip a
>>> few sectors to allow for a real partition table.
>>>
>>> brett
>>>
>> Yes it does Brett, and it works just fine. So let me step up to the
>> podium and preach a bit here.
>>
>> One of my HD's is setup for an os9 allocation/partition of just under 500
>> megs starting at LSN0. By inserting a sector offset that starts with the
>> next sector above that which is in DD.SIZ in LSN0, and some trickery
>> involving the dmode stp setting, this is how we do the 256 virtual 35
>> track SS floppies on the next 80 some megabytes after the end of the os9
>> allocation.  My /sh descriptor is setup to do exactly that. stp is byte
>> wide, so setting its number to anything, $00 to $FF is one of the 256 of
>> these virtual floppies.
>>
>> Not enough? copy the sh.dd file to si.dd, use ded to change its name to
>> si internally, and adjust the offset in ofs and wpc to point at the next
>> startng sector after the end of those 256 vdisks, and do it again.
>> Wash, rinse & repeat for a third set of 256 vdisks named /sj, /sk, /sl
>> etc. Since that is a 1Gb drive, if I was so inclined, I could do it
>> several more times before I was out of drive, but I'd be totally out of
>> system ram long before I was out of drive.
>>
>> As for an LSN0 based partition table I don't recall a thing that makes
>> use of anything past offset $6F, so there is no reason we couldn't
>> implement that 5 bytes at a time in this unused space, for a partition
>> table, 3 for offset, 2 for size exactly as laid out in the first $20
>> bytes of lsn0 now. One could allocate one more byte per partition for
>> the cluster size, thereby eliminating the nominally 131 megabyte limit
>> per partition so added.
>>
>> It could be done, using a mount command that looked up the proper offset
>> from that table, and installed it in just one descriptor, maybe 2 if you
>> wanted to do a partition to partition copy without using the base
>> partition as a scratchpad buffer.  That would certainly save some system
>> ram by getting rid of those data tables in memory, at IIRC, $27 bytes a
>> path descriptor in the boot file. That would require this new mount
>> command needing 2 arguments, the descriptor to modify, and the partition
>> to set it to.
>>
>> Regardless of how its done, present way, or by looking it up in LSN0, we
>> have an ability to do partitioning just by taking advantage of what we
>> have right now.
>>
>> The problem? It's differing individual setups because no 2 of us have
>> identical drive setups. Except for a vanishingly slim chance at the
>> fests, we'll never have identical setups on adjacent tables.
>>
>> But drivewire removes that limitation by putting the differences in the
>> descriptor being accessed.
>>
>> I would investigate, for purposes of moving stuff around at the fests,
>> the probability of setting up a central drivewire server, and with a 10
>> meter usb extension cable such as I use, so my drivewire setup is
>> actually a usb-2 circuit, and if DW can make use of 2 different ports, I
>> don't know that it can, one could publish his latest whiz-bang package
>> to everyone in the room in 45 minutes of carrying the cable from machine
>> to machine. If DW could be convinced to sit there and wait for the cable
>> to be plugged into the next machine without a complicated kill and
>> restart as the cable was moved to the next machine, that would be cut to
>> 15 minutes.
>>
>> Or, if DW will run on the debian jessie installed on an r-pi3, and mount
>> the r-pi on a 6 volt jel-cell, it could be carried from table to table
>> and short cables used, negating the need for that $40 10 meter extension
>> cable, just a good usb to coco drivewire cable 4 or 5 feet long.
>> Drivewire works just fine over usb in the middle of its cabling useing
>> a /dev/ttyUSB# port on this linux box.  My long cable is plugged into a
>> usb port, on a hub this box drives, the far end of that cable is plugged
>> into a 7 port hub on the coco3's desk, and a usb to drivewire cable is
>> plugged into that 7 port.
>>
>> The coco3's printer can also be plugged into this same hub, and has been
>> up until we had the basement work late done last spring. But since that
>> printers other main job is keeping the LinuxCNC configuration listings
>> on my machines up to date, I moved it up to here so I don't have to
>> coerce these ancient legs down and back up a flight of stairs to get a
>> fresh printout. That has been quite handy, and when I bring my coco3
>> back to life, I may just go get another of these brother $110 black and
>> white laser printers and put it on the top shelf of the coco3's desk
>> where this one lived for several years. It will be just another printer
>> to cups in the localhost:631/printers display. And the coco is pleased
>> either way as its a 19 page a minute printer, and the typeface can be
>> any font loaded. To me, the default is such an improvement in
>> readability compared to an old DMP thats its beautyfull.
>>
>> Whats not to like?
>>
>> Its called making use of the resources we already have in the nitros9
>> world. I hope this "sermon" is helpfull. ;-)
>>
>> Cheers, Gene Heskett
>> --
>> "There are four boxes to be used in defense of liberty:
>>   soap, ballot, jury, and ammo. Please use in that order."
>> -Ed Howdershelt (Author)
>> Genes Web page <http://geneslinuxbox.net:6309/gene>
>>
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>>
>> I don't get the comment about sharing the HD.
>
> Superdriver already does partitioning.  Any space on the drive left
> partitioned can be used by whatever. and you can put the os9 partitions
> where ever you would like to.
>
>
> --
> Tim Fadden
> "Hey Schmidt, don't forget about the six P's.
> Proper Preparation Prevents Piss-Poor Performance!"
>
>
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