Notes on 1050-2-PC:

(The file 1050.TXT gives a bit longer technical discussion.  This file
describes features.)

I've had a few people ask me about making a device which would allow the PC
to plug directly into an Atari drive.  After considering whether there would
actually be any advantages, I've started work on a variation on SIO2PC I've
cleverly named 1050-2-PC.  (No, it's not limited to just 1050 drives.  810's
and any other Atari drives which accept the standard SIO commands can be
accessed.)

1050-2-PC requires a different hardware interface, or at least a configurable
version of SIO2PC.  The reason is that the DATA IN and DATA OUT pins on the
Atari computer are swapped on the disk drives (and other peripherals).  This
is so DATA IN on the computer will go to DATA OUT on the peripherals, etc.
Also, the COMMAND line is an output from the Atari computer, but it is an
input to the disk drive.  So, what do we have to do to make an SIO2PC type
device properly connect to an Atari drive?  Well, first you just swap the
DATA IN and DATA OUT wire connection points inside the blue box for the Atari
(SIO) cable only.  The COMMAND line is a bit more complicated.  In SIO2PC it
uses a gate which converts TTL to RS-232.  It will now need an opposite
conversion, RS-232 to TTL.  (Such a gate now exists within SIO2PC as a spare,
if you have the  onechip hardware.)   And, a different handshaking line
from the PC is needed.  Currently the RI (ring indicator) line, which is an
input, is used.  The new hardware will use the RTS line, which is an output.
A further complication is that an Atari drive doesn't put out 5 volts, so
another power source must be used.  I use a 9 V battery and 5V regulator.

Revision 4.05 introduces copy protection support for SIO2PC.  As I've said
before, SIO2PC isn't intended to be a copy protection cracker.  However, the
people who are still using Atari software want to be able to run it from
modern hardware  including SIO2PC and XFORMER for instance.  Anyway, SIO2PC
now includes the ability to emulate bad sectors by using a special code to
flag them, and also by embedding the expected bad (and good) sector status in
the sector data.  I wanted to make transferring your copy protected disks to
SIO2PC images a pushbutton simple process, and it might be if you have the
1050-2-PC hardware which allows the PC to talk directly to an Atari drive.
It can also be done without the special hardware if you don't mind a little
hacking with other tools.

                 Summary of 1050-2-PC Features:

Copy Entire Disk to PC         ³ View Sector Data in Hex / ASCII Dump Format
Copy Selected Sectors to PC    ³ Format Disk
Scan Sectors for Status/Errors ³ Set Up Bad Sector Emulation Info From Scan
Copy Disk Image From PC to     ³
Atari Disk                     ³

I haven't established a firm price on the 1050-2-PC hardware yet, but
tentatively I'm asking $10 over the price of SIO2PC, due to the added
complexity.

Nick