NewTosWorld

[czietz]

ATonce-386SX Software-Version 5.25
PATCHED in 2025 by Christian Zietz <czietz@gmx.net>
... for systems with Alt-RAM
... for Y2K-compatibility
... to remove a CHS bug

### Alt-RAM ###

The ATonce-386SX maps the (optional, but highly recommendable) Fast-RAM to
memory location 0x440000 and above, where it collides with Alt-RAM boards
for the ST, such as the Storm ST, Magnum ST, or MonSTer. During actual
operation this is not an issue, since ATonce-386SX software resets the Atari
before booting into DOS, which disables the Alt-RAM. However, the software
might fail to start with the message "Fast-RAM not installed or faulty" due
to this address collision.

### Y2K ###

The ATonce386SX software passes the date and time from TOS to DOS. However,
the calculations are wrong for years 2000 and above.

### CHS bug ###

The ATonce386SX is off by one cylinder when calculating the cylinders, heads
and sectors (CHS) for the emulated hard drive. In particular, this can cause
data loss when the subsequent partition is partly overwritten. This only
happens in non-TOS-compatible mode ("C" symbol grayed out in hard drive
setup dialog), when DOS fdisk is used to create a partition that spans the
entire emulated hard drive.

### Patched software ###

The ATONCEE.PRG included in this archive is patched to reliably start on
systems with Alt-RAM, to pass the correct date to DOS, and to correctly
calculate the cylinder counter.

The rest of the software should be taken from the official version 5.25
distribution archive.