Atari Mega St Xtra-Ram +8 - May 1993

To:Drive Users

Thank you for purchasing the Xtra-RAM +8 product for your
Atari Mega ST.  We have found the demand for this product is most
encouraging.  Until we re-print the installation guide please carefully
read these notes.

Provided your hard disk driver software is compatible for use with Atari
TT machines, you should have no difficulties in using
a hard disk drive system with the Xtra-Ram +8 product installed.

The XTRA.Prg software informs TOS 2.0x and later that an additional 4Mb or
8Mb of alternate RAM is available and also allocates a 64k FRB (Fast Ram
Buffer) for use by DMA driver (eg: floppy and hard disks).

Software which is TT aware has to know whether a given address is accessable by the
custom chips or not.  Hard disk software, namely Atari drivers 4.0 and
later, assume that addresses beyond the 4Mb limit cannot be reached by
the DAM hardware and so use the 64k FRB to ensure the DMA works.

If you have a hard disk it is very important that you ascertain if you hard disk
drive is compatible with the Xtra-RAM before permanently installing the
software.  If the drive software is known to be compatible with the Atari
tt then all should be okay.  When you run XTRA.PRG it will firstly set up
the additional RAM and then test you hard disk drive - if a hard disk is
attached.  If your hard disk driver software is compatible it should say
so within seconds of testing it.  If it says it is incompatible, or if
the hard disk light stays ON continuously for more than a few seconds,
press the reset button on the rear of your Atari Mega ST and obtain an
upgrade of the hard disk driver software from your hard drive vendor. 
Simply ask for an Atari TT compatible version.

The message 'CANNOT TELL' displayed by XTRA.PRG is normal for non-bootable partitions, so do not be
alarmed by it.

Please contact Marpet for further support if required.