Also, considering the FN-functions are really fast and that you would probably use the same value for the period more than once, you may do something like this:

10 DEF FNM(X)=X-INT(X/M)*M
20 M=256 : REM DO 'X MOD 256'
30 ? FNM(32)
40 ? FNM(256)
50 ? FNM(288)

RUN
32
0
32

That is, rather, the line from the CB2 pin has been re-cenetered, so that it doesn't connect to the resistor anymore. – An odd "correction".

We may observe how the message overlaps the original image and is not in line with the overall aesthetics of the game in general. Also mind how the symbol for the resistor has been mutilated. – Not that promising.

So is this more a hoax?

Regarding A. Brzenska, the oldest references is a German blog article from 2007: blog.c128.net/archives/17

Then, there's a compilation "Space Invaders MR NOP.d64", which shows a copyright message in just one of those games, the 2001 version, which is obviously hacked – and crashes.

There's an old discussion (comp.sys.cbm.narkive.com/alr101u8/who...), where this is attributed to Commodore Japan (which may match up with the hardware knowledge), but, if we compare "Avenger" for the VIC-20 (by Commodore) to these, it's much more like the other, blocky game.

Yes, but for the given time frame, the PET would have been practically available for about a year, maybe less in Japan. I'm kind of skeptical, if a 14/15 year old would have had access to a similar machine before this, in order to learn the required skills. Also mind the knowledge about sound, etc…

BTW, the game was ported to the C64 by Keypunch Software in 1983. Maybe, this is another lead.

On the other hand, according to Wikipedia, Satoshi Matsuoka graduadet from High School in 1982. So this may be a bit early for him.

PS, from an early-1980s aesthetics perspective, I approve of a video game reduced to abstract blocks. This may be the second most 80s sytled game, just after the scuba-colored "Pac Gal" Ms. Pac-Man ROM hack. 😀

Are there any links between A. Brzenska and Commodore Japan?

The other, lesser known Space Invaders for the PET, sometimes also known as "Galaxy Invaders", looks like this (featuring plain PETSCII blocks for game characters and a liberal amount of enemy missiles):

Moreover, there was a Space Invaders game by Commodore Japan. (Compare a short review in Compute! Magazine, Issue 2, Jan/Feb 1980.) Is it this one, or the other one with the smoothly moving PETSCII blocks? (I personally presume the latter.)

Dow we know more about this? Are there vintage ads?

Also, classic arcade games, as in "puzzles in space and time". – I'm going to write a blog post on this (prob. this evening).

Also, where are my manners? The 21st century polite way to put it is, of course, an otherwise empty message reading, "Do you like what you see? Subscribe to the newsletter!"
(All purpose auto-responder.)

If they claim to write similar to my content, they'll know what this means… 😀

Isn't the UX-correct way to put it, "Maybe I'll respond later, first subscribe to my newsletter"?

There's also a physical media kit, including high-res wav-audio files and a PDF for cassette inlay and labels. – Make your own official physical copy of "PET Invaders"!

* This is how it was on the original PET 2001 / CBM series. On later models, Commodore hooked up a simple beeper in the same fashion internally. (These models even start up with a chirping beep sound.) But the overall implementation via a free-running shift register stayed the same.

Yes. The sound implementation on the PET is a bit tricky, as well.
1) There is no sound.
2) But you can hook up a speaker to a 1-bit port of shift register, which fires every time a certain timer runs low.
3) So there are 2 somewhat arbitrary parameters for 1MHz pulse audio to fiddle with.

"…floppy space bar…" – floppy space bar? – wait a minute, my floppy has no space bar, never seen one – oh, "floppy space bar"!

It's just that I wasn't happy about the term IP being introduced into this. (As explained, this is something entirely different to me. And nothing of this is related to the specifric identity of enties.)