[Coco] I'm missing something obvious

Robert Gault robert.gault at att.net
Thu Jan 14 01:07:54 EST 2016


Ed Orbea wrote:
> I was able to obtain a couple of 1gb CF cards for use in my SuperIDE in my
> CoCo3. I do have several SDC pack that work very well, so this is more of a
> ‘wanting to explore’ type of thing.
>
>
> I have done these steps to try to use these cards.
>
> 1) Run the IDEPROBE.BAS program which says the CF cards have this
> configuration:
>
> 1966 total cylinders; 16 heads; 63 sectors per cylinder, 1,981,728 total
> sectors and the card supports LBA mode.
>
> 2) Run the WIZARD.BAS program and provide these inputs: base address FF50,
> total sectors 1,981,728, 512 bytes per sector, 256 HDB virtual drives and
> LBA mode. The output is: OS9 capacity 888.89mb, HDB capacity 78.75mb, with
> an HDB offset of: 1BC720
>
> 3) I create the ROM and the BIN file via the WIZARD.BAS program
>
> 4) I flash the ROM image into bank 2 of the SuperIDE
>
> 5) Reboot the system using the SuperIDE and enable floppy drives (POKE
> &HFF7F,3)
>
> 6) Use the FMTALL.BAS program to format all 256 virtual drives
>
> 7) Create a 6809 Level II, NitrOS-9 3.0.0 35 track SSSD floppy and copy
> that disk to drive 255
>
> 8) Run LINK.BAS to link drive 255
>
> 9) As /i0 is not yet formatted, I use an 80 track DSDD disk to boot into
> NitrOS-9. The DSDD has RBSUPER, DD_I0, etc
>
> 10) When I execute dmode for /I0 it shows: nam=I0, mgr=rbf, ddr=rbsuper,
> hpn=07, hpa=FF50, drv=00, stp=00, typ=81, dns=00, cyl=007F, sid=40, vfy=01,
> sct=0020, t0s=0020, ilv=01, sas=10, wpc=00, ofs=0000,rwc=00
>
>
> So the information from dmode does not match the size of the OS9 drive.
> Thus my question is what /I0 setting do I need too change via dmode?
>
>
>
> +----------------+
> *Ed Orbea*
> Poulsbo, WA
>

Ed,

Just looking at the data you presented, something is wrong. If the HDB offset is 
$1BC720, then there are 932,069,376 bytes in the OS-9 partition which does not 
match "OS9 capacity 888.89mb".

Anyway, you want the product of sct*cyl*sid = total sectors. Your total cylinder 
count is $7AE with $10 heads and $3F sectors per cylinder. Allocating $1BC720 
sectors to OS-9 means:
$1BC720/($10*$3F)=$70E or cyl=070E sid=10 sct=003F t0s=003F

You should verify the math. You also need to make sure how your software handles 
512-byte sectors vrs 256-byte sectors. Are you packing two OS-9/Disk Basic 
256-byte sectors in each 512-byte sector or wasting 256 bytes of each 512-byte 
sector.

I'm not familiar with the SuperIDE so I could be completely wrong with the above 
analysis.

As Bill mentioned, the Allocation Map (DD.MAP) needs to be large enough to 
address the size of the OS-9 partition. DD.MAP can be up to $FFFF bytes and at 
1-bit per sector can't address your drive.
You will need to tell format to use at least a cluster size of 4, but 8 or 16 
might be better.

Robert


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