P112

[Bill Gunshannon]

On 12/3/19 11:00 PM, Lamar Owen wrote:
> 
> 
> On Dec 3, 2019 8:55 PM, Bill Gunshannon via cctech 
> <cctech at classiccmp.org> wrote:
> 
>     Especially RSX180 as I have some other plans for that one.
> 
> RSX180?  Learn about something new everyday!  This tidbit alone was 
> worth watching the thread.
> 

Well, glad it helped.  And here's more...

I have succeeded in getting RSX-180 installed on a hard disk.
In doing so I have learned some things that others might consider
valuable as well.

Disk sizes and formats are more important than one might realize
from reading the support page.

Oversized hard disk partitions cause really strange behavior totally
unrelated to disk I/O.  When I tried to use a disk partition that was
too big the system merely spewed garbage to the screen.

But the second lesson is even more important.

The Support Page states:
    "For best performance format the floppy first under CP/M, so
     the sectors will have the optimum interleave value for the
     P112 hardware. Otherwise, disk accesses will be very slow."

This is not accurate.  When I used a brand new pre-formatted floppy
without formatting it under CP/M it booted but many of the commands
failed to work and even th4e directory could not be seen.  Formatting
on CP/M and then using rawrite to place the image on the floppy fixed
that.

I have been having a problem getting CP/M 3 to boot and now suspect
it may be the same problem.  Again, I used a pre-formatted brand new
floppy and rawrite.  When I try to boot it starts loading and then
spews what looks like random garbage to the screen.  I am going to
try using a CP/M formatted floppy and I actually expect it will fix
the problem.

bill