ARENA an Old/New game

[GCHarder]

Screenies

Arena Screens.jpg (144.79 KiB) Viewed 7540 times

Here's another program of mine I resurrected from a listing from Syncware News. It's was my only attempt at an arcade style game. Hopefully, there's no major bugs because without an annotated dis-assembly it would be hard to find it.

I've also included the scanned pages as well. Check out the great full page ad from Silicon Mountain Computers AKA Fred Nachbaur.

Regards;

Greg

[siggi]

Hi Greg
I tried to play the game, but is too fast for me (living in the 50 Hz part of the ZX81 universe ), especially caused by the strange keyboard layout. I then tried to play it using KMURTAs Joy81 card (programmed for the strange keys), but the game does not respond to the "keys" generated by Joy81

But no bugs occured till now

Siggi

[GCHarder]

Change line 860 POKE 16910,B to
860 POKE 16910,B*2 or B*4 or B*6...

I don't think it will break anything else.

Don't know what to say about the keyboard, that's not an easy change as it's based on the keyboard "sections" not on individual keys. I find Z-X-C-H works well, but I'm using a standard keyboard not a real ZX81. I've played it in three emulators with not problem.

Sorry;

Greg

[kmurta]

A nice game and I like the graphic effects, very good!

Thanks Greg, for share that with us.

By the way, have you available the SHR Extended BASIC documentation?

I then tried to play it using KMURTAs Joy81 card (programmed for the strange keys), but the game does not respond to the "keys" generated by Joy81

Siggi, use the keys Z,X,C and V to program the JOY81

The game seems to read all keyboard sectors simultaneosly so there are no differences in type keys ( SHIFT Z X C V ) or ( A S D F G ) or ( Q W E R T ) or ( 1 2 3 4 5 ) or ( 6 7 8 9 0 ) or ( Y U I O P ) or ( H J K L NL ) or ( B N M . SPC ). It is as if we had just 5 keys in the keyboard. But in this case the JOY81 only recognize the sector 0 ( SHIFT Z X C V ).

[GCHarder]

Sorry, all my hardware, mags, software etc. was stolen from a storage shed long ago. Luckily, I scanned a few items but not that. As I recall, I don't think I ever had any paper documents for that, maybe Fred put one together.
I've been thinking of dis-assembling the code, a daunting task since its 6K. I do know there's a jump table in there somewhere, once you find that you'd at least know where each individual routine is located.

Your right about the keyboard. Again, I don't recall why I did that, but I think it has to do with reading the keyboard port directly IN A,(FE) I think, and bypassing any ROM routines to decode the key pressed. Very fast, but limited, keyboard read, good if you only need a few keys.

Regards;

Greg

[siggi]

Thanks Kelly for your hint about the JOY81 keys. Now I can play the game without "applying the handbrake" (POKE ...)
And thanks to Greg for this nice old/new game

BTW: I have got long ago the SHREB documentation (but not of the latest SHREB version). But it is a copy of a matrix printer document and hard to read even on paper....
I could try do dig it out and scan it???

Siggi

[siggi]

Here is the SHREB documentation!

SHREBDOC.zip

(708.27 KiB) Downloaded 306 times

Wilf Rigter scanned it in 2005 for me. The files are a graphical format, which can be viewed using this program (Wilf also sent me this link in 2005, and it still works!!!!):

http://support.visioneer.com/utilities/viewer.exe

Have fun
Siggi

[kmurta]

Here is the SHREB documentation!

Thank you very much, Siggi!

I'll take a closer look once I have some free time.

[GCHarder]

With redefineable key patch

[JohnsBargs]

I like it, although it's a bit harsh when antimatter debris gets dumped in the square right next to the centre so you can't do anything about a shot from that direction. Also not quite sure what the point of the "moles" is.

It reminds me on a superficial level of Space Zap, which I was always surprised never got a port to either the Zeddy or the Speccy, being a super-simple but fast, intense and addictive game that would have been easy to do on either machine.

Bit of box art: