I have just got a 4032 pet.I learned basic on a pet back in the early 80's and remember someone playing pet invaders and would like to get it running on my machine.I got a few tapes and one of them is pet invaders (I remember the schematic for sound output that appears when it first loads) but even though the sound schematic appears on my pet on pressing a key I just get a blank screen.Could be that the tape is just too old or maybe I'm doing something wrong.My pet has 4.0 basic and 32k of memory and I'm using the 'new rom' version of the game,I just type LOAD then RUN once the game has loaded  but it just won't work.Any ideas?I have found a copy of the game off the net but putting it on a tape for my  pet is going to be difficult.I thought maybe I could load it into an emulator like winvice and copy the machine code to type into my pet but not knowing the start and end of the actual machine code I could end up typing in 32k of code! Do any of you either know any tricks I could try to get my tape working or somewhere I could obtain another copy?I live in the UK.
Any help would be great.Thanks.

Hm. I wonder if the good old software suite WAV-PRG and AudioTAP supports PET? Since the timing is inbetween VIC-20 and C64, they probably would work. In that case you could take a PRG file and convert to WAV, connect a regular tape recorder to the speaker output of your sound card and record it onto a fresh tape.

Otherwise there are a couple of different solutions involving various cables etc, depending on how much you want to work to get the desired result.

I was going to try this if all else fails as from what I can gather it's VERY difficult to actually copy the soundfile onto a tape good enough for a pet to read it.If I ever do get around to trying it I'll post the results.

'new rom' refers to Basic 2. When Basic 2 was released there was no version number displayed, so it was just referred to as 'new rom', with Basic 1 referred to as 'old rom'. Only when Basic 4 came out did people start calling them Basic 1 and Basic 2.

Fortunately for you there is little difference between Space Invaders for Basic 2 and 4. I wrote a little diff program to see what the changes were. Only ROM interrupt entry location needs to change.

So load your Basic 2 version, and using the Machine Language Monitor change:

0511 a9 2e becomes a9 55
0516 a9 e6 becomes a9 e4
0a51 4c 31 e6 becomes 4c 58 e4
19a5 4c 31 e6 becomes 4c 58 e4

Dave

HEY-It worked.Nice one.Loads of thanks dude.I thought it was just not loading properly but that fixed it up fine.Now to relive those memorys.