The connector on the monitor is called PL-259 or UHF, and was commonly used on security monitors and closed-circuit TV systems. The transformer in the back of the case is an isolation transformer, because cheap TVs were normally hot-chassis, but in order to add the direct video input it needed to be grounded and isolated from the AC line.
The only real difference between the II Plus and the original II is that it came with Microsoft-based Applesoft BASIC instead of Woz's own Integer BASIC in ROM. The very early II's also had some quirks like a lack of cooling vents in the case (so needless to say, they badly overheated), no autoboot (when you turned it on, you got a screenful of garbage and needed to press Reset to get it to boot), and no color killer (causing rainbow fringing in text mode on a color monitor). The vast majority of original II's were upgraded to II Pluses, but now people are reverting them back to original form because they're worth so much more to collectors (into the thousands).
I had an Apple 2+ purchased around June 1980 with lots of upgrades. I had the 16k language card, a parallel port card for an epson mx80 clone from star micronuics, 300 baud modem, 80 column card, cpm z80 card, 2 floppy disk drives, and the lower case mod - I think it was a new character set and a wire to the right side of the joystick socket.
As I recall, the Apple II Plus upgrades the base Apple II from 16K to 48K of RAM, and also adds an auto-boot ROM by default (the original Apple II you'd have to manually tell it which device to boot from). Beyond that, I too am not all that familiar with any other differences.
Wow! I picked up a similar bundle (although it was functioning) a few weeks ago and I definitely did not get it for free haha. I’m excited to see you get it working!
I found something interesting in my aera too I might buy it. Found a still sealed in the box Maxtor 250gb IDE hard drive. Would love it for a cold spare for a old usb hard drive I have.
Open the power supply to check for RIFA capacitors - if they exist they will explode on you so replace them asap. My apple 2 died in 1985/6 from them exploding very young. At the time I didn't know but I realize in 2024 they were the problem. You can also get modern replacements - the macintosh librarian did a video on how to do that.
