I haven't found any reference to my specific problem, so I decided to open a new topic.

My problem is that the APE for Windows (USB) software with the Atarimax SIO2PC USB adapter does not let me load or send any data (i.e. read virtual disks or send printed output) between my Atari 800XL and my 64bit Windows 10 computer. However, I am able to use ProSystem to create virtual disks on the Windows computer and create real 8bit floppy disks on my Atari 1050 disk drive.

I'm using APE for Windows v3.0.15, which is registered to me. I'm starting the software using the USB ONLY mode shortcut that was installed on my desktop. I don't see anything that looks like error messages in the APE for Windows window when I'm trying to boot the 800XL from a virtual disk (tried several, all containing Atari DOS files) on my Windows computer. There are multiple lines of text in the APE for Windows log screen:
Device: 31 Command: 53 Aux 1: 00 Aux 2: 00 Checksum: 84 (repeated over 20 times), followed by
Device: 4F Command: 40 Aux 1: 4F Aux 2: 4F Checksum: 2E (repeated over 20 times), followed by
Device: 4F Command: 40 Aux 1: 00 Aux 2: 00 Checksum: 8F (repeated over 20 times)
and finally the 800XL opens the self test screen.

I get the messages:
[Device Manager] RS232 Driver Disabled. (USB ONLY Mode Enabled)
[Device Manager] APE USB interface detected and configured.
when I start APE for Windows.

It is confusing to me that ProSystem works, but APE for Windows doesn't. I don't remember making any changes in the APE for Windows configuration window. ProSystem is using the COM1 port.

I tried many different setups, such as: 1) booting from a 1050 drive set to drive 1, and trying to access a virtual disk as drive 2; 2) booting directly from the virtual disk set as drive 1, with the 1050 drive turned off; 3) booting directly from the virtual disk set as drive 1 connected directly to the 800XL. I tried the setup with two different Windows computers. Same results everytime, doesn't work.

I also have a homemade SIO2PC cable (USB to SIO), and have successfully used my 800XL with a virtual disk (using the same virtual disk as when testing the Ape for Windows setup) on the Windows computer with the ResepQt software.

I'm hoping that someone has worked through this problem before, and can offer suggestions that will get my system working.

Perhaps this helps, I moved to a 4-port USB 2.0 HUB, not using the SS or USB3 ports on my PC.
That solved my issues with detected or not detected Device.
Also I had quit often the Blue Screen of death (yes on Windows 10) in the middle of normal IO.
That issue is also fixed now, with use of the HUB.

Also I noticed that using the backup software, power to a 1050 alone does not work for me.
I have to power the 800XL too, for the communication 1050-PC to work.

mr-atari, Thanks for your suggestion. I don't have a hub to test your idea, so haven't tried it yet.

However, I was able to contact Steve and provided him with detailed information about my problem. He suspects the SIO2PC interface has a hardware problem, and is sending me a replacement.

Thanks Steve.

Problem solved. The interface was defective. Steve sent me a replacement unit, which worked just by plugging it in without making any software and/or driver changes on my Windows computers.

Perfect.

Steve is a great guy, top notch service always.

I'm using registered 3.0.11 (printer upgrade). Got a new error message while trying to print out a Basic listing (using the MX-80 graphic printer feature).

"Printing pages disabled. (printer index out of range.)

My listing will print to APE, but hangs if I try to physically print the page out. I uninstalled APE and reinstalled it, but had no effect. I rebooted the PC -- same result. I went through the network diagnostics -- still the error. Any thoughts on how to fix this and what the error message really means?

Thanks,
Larry

Well, it's working again. Like most issues with Windows, I have no idea exactly what fixed it! But it lives!
But if anyone can add any info about the error message, I'd apppreciate it. (Google was not very helpful.)