[Coco] OS9 help needed.

[L. Curtis Boyle]

There is a temporary way to patch d0 after you boot, using MODPATCH (which is included with OS-9 Level II). You can use this to change d0 “on the fly” to 40 track double sided, and then you make a new boot disk with that modified descriptor in memory.

So, in your case:
1) Boot your original Lvl 2 floppies
2) Type MODPATCH (warning - it doesn’t have prompts)
3) Type L D0 (link to D0 module). If successful, it will print D0 on the screen.
4) Type C 18 23 28 (This changes # of tracks from $23 to $28 - 35 to 40 in decimal)
5) Type C 19 1 2 (This changes # of sides from 1 to 2)
6) Type V (re-verify the CRC on the module)
7) Hit SHIFT-BREAK (ESC) to exit modpatch.

At this point, you should be able to access the drive as 40 track double sided, until  you reboot. You can also COBBLER a new disk which will have the new 40 track, double sided D0.


L. Curtis Boyle
curtisboyle at sasktel.net

TRS-80 Color Computer Games website
http://www.lcurtisboyle.com/nitros9/coco_game_list.html



> On Dec 23, 2018, at 6:32 AM, Walter <zambotti at iinet.net.au> wrote:
> 
> Hi
> 
> 
> 
> I found my original OS9 Lvl 2 floppies.
> 
> 
> 
> Can someone remind me how I can access a 40 track double sided floppy if the
> boot floppy
> is 35 track single sided?
> 
> 
> 
> I tried loading the d40_ds.dd from the modules directory but of course it
> can't overwrite the
> 
> /d0 module that is already in memory.
>