Milestone 2 – Ray path working

I’ve got the ray path working, after fixing about 4 bugs in various routines.  Z80 is a bit more difficult than my ARM and X86 assembler experience.

deflektor5

I have, however, realised an error in my design:  The double-sided mirrors have only 8 discrete angles.  I need to increase this to 16, in order to be able to reflect the rays along the “22.5” degree paths!

I will need to draw 8 more mirror sprites (argh) and alter the enumeration encodings for the board pieces to accomodate the extra mirrors.

Code changes ahoy!

Jonathan.

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Time to write some Z80

I haven’t written any Z80 for about 20 years!  But having written the emulator for a computer that had basically no software, it’s time to perhaps add some!

George Kendal’s “fast work” article from Lynx User magazine has been very useful for adapting some of my own custom sprite-drawing routines, that I hope will work on a real Lynx.

Meanwhile work is in progress…

deflektor2

“I wonder what this might be?”

No promises when, although I will open-source it.

Jonathan.

Making a TAP file for Star Rover

On Hyperspin-fe, Craig Anderson asks whether he can have a TAP file of STAR ROVER.  Well, the best way is to make one!  Here’s how…

1. Go to my STAR ROVER post, and COPY the program listing to the clipboard.  Make sure you have all of the lines precisely selected.

2. Open Windows Notepad.exe and PASTE in the listing.

3. Save the file from Notepad.  Encoding UTF-8 or ANSI will do, but not anything else.

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4. Start a fresh Jynx session.  Select Super Speed Console on the Speed menu.

5. On the Text menu select Type In Text From File… and choose the file you saved from Notepad. You may need to press ENTER to enter the final line of the program into the Lynx!

6. Type:    SAVE “STAR ROVER”,10    and press ENTER.   The Lynx is saving the file to a virtual cassette in the memory of the emulator.

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7. Once the Lynx has finished saving, and since there is nothing else to be added to the “virtual cassette”, save the virtual cassette as a TAP file on your host computer.   On the File menu select Save as TAP file…

Congratulations!  You now have a TAP file you can use with the “Run TAP file” option on the File menu!

  • The program will automatically RUN because you added “,10” at the end of the SAVE command.   This tells the Lynx to automatically run the program from line 10 when loaded.

Jonathan.

ROADER – update

Earlier this week I was chatting to Frank Rasmussen about the ROADER game on the Camputers Lynx.  My attempts at making this game work began to involve suspicious amounts of effort!   This led me to believe that the game is broken.

Well, Frank has e-mailed me this afternoon.  He’s taken the time to check out the game on real 96K Lynx.  And…  It turns out the game appears to be broken.

Roader1

The car leaves a trail of dots on the screen which, by virtue of the scrolling, wrap around to the top, and descend.  The car then starts “bumping into” the dots trail.

I don’t really know what I am going to do about this – I could hack this and see if I can remove the dots.   That would leave the text positioning problem, and the problems with the main screen.   I have my doubts the program initialises properly, either, since sometimes the “crashed” car sprite is shown as the primary image!

There’s slightly too much wrong with this game to want to disassemble it all, and follow it through, and fix it. Might just re-write it.

Jonathan.