VAPI2SIO
Copyright c 2005 by Jorge Cwik

http://vapi.fxatari.com

Vapi2sio is a mini SIO2PC/APE Windows program for running VAPI images under 
real Atari hardware.

This is by no means a full-fledged application, and probably will never be. 
You can only load a single Atari image in drive D1:. The only option 
available is to write protect or write enable the image.

The program requires the VAPI.DLL and the only images types allowed are the 
ones supported by the DLL. Currently they are uncompressed VAPI and ATR 
images.

There is an option to buffer the whole file image in memory or not. This is 
not for the purpose of saving memory usage. Atari images are small enough 
that memory shouldn't be a problem unless you are using an extremely old PC. 
When an image is wholly buffered writes are "lost on-eject". This means that 
the actual file on the PC is not modified. So disable whole file buffering 
if you want to permanently modify the image (but not that writes to VAPI 
images are currently not supported by the DLL).

Disabling whole file buffering, on the other hand, might create small delays 
when accessing the image. This might be relevant for some copy protected 
programs if the file resides in a slow media.


Operating system specifics:

Windows 9X/Me

The program was tested under Windows 98 SE (Second edition). It should work 
under Windows ME, and probably under Windows 98 Gold (not SE). I don't know 
for sure if it will work under Windows 95.

A special provided virtual driver is required under these operating systems. 
The driver must be present in the same directory than the main program. Only 
a standard PC serial port is supported. Converters like USB to serial, or 
serial cards not 100% compatible will not work. Both "RI" and "DSR" cable 
types are supported.

Windows NT derived versions.

The program was tested under Win 2000 and Win XP. It should work under 
Windows 2003. I don't know if and how it will work under Windows Vista or 
Windows XP-64. The driver for these systems is a user level one, currently 
no kernel driver is provided. This has the advantage that "anything" that 
has a COMx interface is supported. In particular, USB converters are 
supported. But it depends on many other factors (both software and hardware) 
how well (if at all) they will work.

The cable type under these systems must be of the "DSR" type. The old APE 
cable using the "RI" signal is not supported. The Atarimax three-in-one is 
both cables at the same time, so just select "DSR" as the cable type.

The program should work fine under Windows NT 4 as long as you configure the 
serial port FIFO correctly. Logged in as Administrator configure the "FIFO 
receive trigger" as one (the minimum). For later NT systems this is not 
required and the program does it automatically.


In general, the accuracy and reliability of the program depends on the 
relative load of the computer. This is a real-time application running on 
operating systems not designed for this purpose. There is no specific 
minimum requirement for CPU speed or memory. It depends more on the relation 
between the power of the PC and the active processing. User level programs 
running on the background should not affect too much. But drivers, anti-
virus, and similar programs might.

The Win 9X version is more accurate. With it virtual driver it talks 
directly to the hardware and takes almost full control of the PC at the 
critical points.

You might find that several VAPI images don't run on your computer. There 
are programs that, in their original copy-protected form, don't run on 
computers with more than 64K.
