QubertWI

A different SD card works fine. Im glad it wasn't a stupid error on my part! Thanks Jon - I really appreciate your work and responsiveness!

The loader is version 0.44. I'll try a different SD card next.

UFLASH reports the PBI BIOS as "PBI.BIOS" version 1.0. Is this correct?

Here you go... Ballblazer (1987)(Atari).car

I attached an image but I guess it needs to be approved by a moderator,,, My BIOS plugin say "VXS3STCO".

Here's my BIOS settings. Can I assume the S3 in the Plugin section is for the Side 3?

I've just gotten into the A8 hobby and I am, therefore, a newbie. I've tried solving this problem on my own but after hours of reading and watching videos I am stuck. I have an 800XL into which I've just installed a U1MB along with a Side3 cartridge. I've updated to flashjazzcat's latest firmware on both and everything seems to be working except for 1 problem. I can mount and run cartridges (CAR files) that are 16k (17k for CARs) or less in size, but anything larger does not work. A good example is Ballblazer from Mr Robots CAR file collection, which is a 64k cartridge. When I have the U1MB enabled, mounting the cartridge gives a screen full of BOOT ERROR messages. If I disable the U1MB, mounting the cartridge takes me to the Atari Self Test screen. I'm using this one cart as an example, but i have been unable to mount any larger car files, and I have tried many. Anyone have any ideas on what I've done wrong?

I've always been a Commodore guy but I've collected various 8 bit systems over the years. I retrieved a bunch of stuff I had in storage with the intent of selling most of it off. I had a couple of Atari 800XLs and 1050s that I needed to clean up and test before selling, and I found AtariAge while searching for information on repairing one of the XL keyboards and one of the 1050s. In the process, I discovered this whole new world of Atari. I managed to get everything working and next thing I know I'm installing a U1MB and a Side3 and having a ball. The amount of community activity and the quality of the new hardware and software for the Atari systems is really incredible - much more than the Commodore scene. Anyway, I've also purchased a UAV so I could connect it to a Commodore 1084S monitor using the luma and chroma signals, but I also want to use it occasionally with a composite (combined signals) LCD monitor I have. My question is... does installing the UAV disable the composite signal?