[Coco] Need help using ram drive as default drive

[gene heskett]

On Thursday, June 23, 2011 08:50:20 PM Vanderberg Family did opine:

[...]
 
> Yes, that is a change - from my brain to my fingertips. was really Pipe
> Clock Clock2 i2xtot*j (module not found?)

Chuckle.  We call that PEBKAC, problem exists between keyboard and chair. 
;-)  Or PEBCAK, interchanging chair and keyboard.  It is pretty common here 
too when I'm battling the inevitable arthritis of 76 years of hard work 
they've done.

> Last night I started all
> overwith orig distrib disk -no mods
> Rebuilt using all stock descriptors for all hardware to eliminate any
> self-inflicted errors. I really thought that it would work - /ddr0
> SHOULD work as default drive, or why does it exist? Same results
> exactly.
> If I gen using /ddd0 as default, everything is great (no progress, but
> it works as it should) however if I change to /ddr0 with no other
> changes in my standard.bl for os9gen, the boot fails with 12xtot*j

Well, maybe, but you are walking on and plowing dirt that hasn't been 
plowed in this manner before, so its hard to tell what may turn up.
> 
> >Humm, so my next question is: are the /r0.dd and /ddr0.dd descriptors
> >you are using an exact match except for the internal name and crc?
> 
> They weren't and I thought that may be the problem which is why I
> started over from distrib disks.  No luck
> 
> >> I tried the above stock and also after copying /r0_192k.dd to
> >> /ddr0_192k.dd and using ded to modify the R0 reference to DD (44 C4 -
> >> correct?)
> >
> >Yes.
> >
> >> to try to avoid the expected /ddr0 choke on the preexisting
> >> /r0 with diff format.  Did this make sense to you?
> >
> >Post a dump of the /ddr0.dd you are trying to use, please.
> 
> I can, but I am now using the orig so I don't think you really want to
> see them now.
> 
> >> In other words, I am trying to change a working standard.bl to use
> >> the /ddr0 descriptor from the distrib disk. So, my question is what
> >> needs to be done in addition to selecting the /ddr0 descriptor in
> >> order to enable ram drive as default?  If I am thinking correctly,
> >> that change will achieve all I have described.  THEN I can think
> >> about /r0 as a boot device on warm boots - another question for
> >> another day.
> >
> >A warm boot from the ramdisk, unless you can figure out how to swap the
> >boot module that is in memory, cannot be done.  However you can make
> >everything run from /r0 by editing sysgo and fixing the help and error
> >files I alluded to above.
> 
> Not trying to boot from ram disk - booting from /d0, just trying to
> establish /ddr0 as default, not boot.
 
I don't believe that can be made to work.  The best you can do is I think, 
use the startup script to put you on the ramdisk after the backup command 
has refreshed the ramdisk.  The boot, or reboot, will be from the /d0 
floppy in all cases, so that floppy will need, in addition to track 34 for 
the initial boot, the os9boot you os9gen'ed on it with MB, probably 
utilpak, Sysgo, cmds/backup, and a custom startup.  You cannot use an 
edited SysGo because it runs too early, before the backup.  Put your backup 
command in the startup file, and once that's done, then chx /r0/cmds, and 
cd /r0.  The backup will then be done every boot/reboot, but I don't see a 
way around it.

> >I assume we are talking about a half meg coco3 here, which will
> >eventually run out of /r0 to add stuff to.  I have a 2 meg disto kit
> >in mine that I have used at 1.7 megs, but those haven't been on
> >fleabay anytime I know of, fleabay itself is too new.
> 
> Yes, my mother told me envy was bad so I should wish I had your 2-meg
> and you had a better one <grin>

And a grin back at ya.  In fact, I am somewhat amazed that Mark or Roger 
hasn't built a new design of a 2 meg kit.  IMO there is yet, a market for 
such a kit.  Somebody, way back up the log, made a one off of an 8 megger, 
but from what little I know, that would have needed some pretty intrusive 
patches to os9/nitros9 to use it.

The only magic in the disto kit is an added register that furnishes the 
upper address bits missing in the gime chips registers, and another I think 
2 bit counter added to the refresh counter.  The memory itself is just a 
pair of the usual 30 pin simm's, 256kx16's.  Running at the coco's bus 
frequency, those simm's make zero heat, or as close as never mind.  Since 
all the power supply stuff, which is a huge heat src in the coco's, has 
been excised for close to 20 years now, and an old AT PSU in the bottom of 
the drive tower powers it all, so I can toss a furniture blanket over the 
coco with a darkroom thermometer laying over the ram on top of the case, 
leave for 2 weeks and the thermometer might be 2F over room ambient when I 
get back.  I also got my fill of the finger pattern on the MPI oxidizing at 
2 week intervals, sawed it off and put a set of gold plated fingers on it, 
sawed off an old PC video card with each finger connected by a dot of hard, 
silver bearing solder.  That also was nearly 20 years ago, and I've not had 
a bad contact with the mpi crash me since.  And of course it got a heart 
transplant when the 6309 was discovered, a wee bit faster & again its all 
cmos, so zero heat.

Finally, all 4 MPI sockets have their pin 8's bridged together, and 3 of 
the 4 pullup resistors also connected to those pin 8's have been removed, 
so missed interrupts are a thing of the past.

Yeah, I'm a tinkerer and maybe a JOAT even.  I've been chasing electrons 
for a living for 62 of my 76 years.  Funny thing though, that, and a buck 
35, will get you a 16 oz coffee to go at 7/11.  ;-)

> I understand the limitations and accept
> them, however for my purposes the size works well.  I format the /r0 to
> match my 40tSS /d1 which allows me to flash a whole new (albeit tiny)
> hard drive in about 30 seconds using backup.  Far better than dsave to
> repopulate ram drive.  So I have a prebuilt image (from diskette) on
> ram drive to match my current purpose.  #1 CMDS, SYS, etc.   #2
> Basic09, support files and progs   #3 Games requiring diff setup or
> that access a drive for routines (speed)  #4 Multi-Vue (just playing).
> My point is that withing 30 seconds I have a small "harddrive" custom
> tailored to my current task.  This only works well as the /r0 is
> formatted identical to /d1 so for me, maybe only 512k is a blessing.
 
Well, if /d1 was a 720k floppy, 3.5 or 5.25, the 2 meg kit would allow you 
to add quite a bit more to that floppy image.  Just saying.
The fact that you have a 40tSS disk to be used to populate the ramdisk 
makes the fixing of help and error very easy.  Patch those 2 files, help 
and error, for starters so they look in /r0/sys.

> Has anyone actually used any of the /ddr0 default ram drive descriptors?

I have not, nor could I do the backup since myram's LSN0 is a bit odd, as 
is the descriptor, backup would see that and dive off the deep end.  To 
simplify the ram paging, a dmode /r0 looks like this:

{t2|07}/DD/NITROS9/6309L2/MODULES/RBF:dmode -r0.dd

 nam=R0 mgr=RBF ddr=RAM
 hpn=00 hpa=0000 drv=00 stp=00 typ=00 dns=00 cyl=0000 sid=01
 vfy=00 sct=1000 t0s=0000 ilv=00 sas=04 wpc= ofs= rwc=

Note, cyl=0000, this is the variable you change with dmode to change its 
size and it uses an 8k page/block of ram for every cyl(inder) there.  
Setting cyl=AF gives a 1,433,600 sized ramdisk.  sas=04 is also too small, 
for that size disk I'd set it to 40.  It is self formatting on the first 
access after a boot, if not in use it can be 'deiniz /r0' and returns every 
byte to the os9 memory pool.  But it wouldn't work for you for the same 
reason I couldn't use it in this scheme.  Well, I could, but doing the 
backup with the tool I'd have to use will add a couple minutes to the boot.  
And I would have to re-write my tool to skip lsn0 & start the copy with the 
FAT on LSN1.

The above dmode output actually came from my coco3 as its live in the 
basement and I am using a terminal proggy here, connected to the deluxe 
rs-232 pack at 9600 baud.  So the coco3 is just another terminal screen 
here.

> And again I thank you and all others for the help.
> Ed

NP, we are also refreshing my ancient wet ram as we go.  Lets just say it 
is in need of the refresh. :)

Cheers, gene
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Experiments must be reproducible; they should all fail in the same way.

Cheers, gene
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Hoffer's Discovery:
	The grand act of a dying institution is to issue a newly
	revised, enlarged edition of the policies and procedures manual.

Cheers, gene
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Hoffer's Discovery:
	The grand act of a dying institution is to issue a newly
	revised, enlarged edition of the policies and procedures manual.