The TRS-80 Journey Continues

Bill Gunshannon bill.gunshannon at
Wed May 11 18:04:42 CDT 2022

On 5/11/22 10:34, Mike Katz wrote:
> I don't know about TRS-DOS but a lot of early floppy disk format 
> programs had an option to make the formatted disk bootable or not. This 
> would copy the bootloader to the appropriate location on the floppy, 
> copy the OS to the floppy and update any necessary pointers to the OS on 
> the floppy.

That's what i thought, too.  But I have been unable to find anything
like that in any of the documentation I still have.  I did find that
the SYSGEN Utility under DOSPLUS may be able to that.  But it may
only work from floppy to floppy and not when the system is booted
from a hard disk.

> Usually a ROM bootloader would load a known sector (usually Track 0, 
> Sector 0) and execute the code from that sector.  That code would then 
> get the address of the Operating System from the disk (either in a fixed 
> location on disk or a fixed location in the directory) and load the OS.

That's the way I have always known it to be. Thus why I said if
I work on a project to build boot floppies from hard disk systems
I will have to have a collection of BOOT Code for the various OSes
and know how they use it.  I guess the first thing I will need is
a program to read raw data from a floppy and another to write raw
data to a floppy.  This looks like a perfect job for PL/M.  :-)


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