LinkoVitch

Just for giggles, the bug in my branch making code?

The second branch object, for some reason I had shifted the YPOS field 2 bits instead of 3! so it was getting an object code of type 7! The OP wasn't too happy with that it would seem otherwise it seems to work YAY!

Yes, you must have 2 branch object to inform the OP to not draw :

- before VDB

- after VDE

 

It could be that ... Here is the piece of code I use (not sure the comments are good ...) :

No, I can say it definitely IS that

Hope you are attending AC2011, so I can thank you with beers

Looks like your branch ordering at the start is the opposite way around to mine, but also has highlighted another bug in my own. Having a working list to go from will be a big help in fixing my own code so its a double whammy

Thanks again.. now ONWARDS!

It is probably that you're missing the branch objects and it thus starts drawing 6 lines before it should (I'm guessing the OP doesn't reset VC until it gets to VDB, therefore it starts drawing those 6 lines with the old VC which was at the bottom of the screen).

Its not drawing early, it draws at the right time, just that the data it is drawing is starting 6 lines into the object, so the top 6 lines are missing. The object is also in the middle of the screen.

However, you should also check to make sure that your bitmap data is phrase aligned.

It is, the object appears correct and not skewed. I am going to try as Matmook suggested and see if he OP is simply having a hissy fit due to the lack of VDB/VDE branches.

Hopefully find out tonight, assuming I can pull myself away from my planned tasks

Cheers Matmook.

I will give that a whirl, having some working branch object code to look over may help me fix my own too (wrote some for VDB and VDE areas but it isn't working properly so I was lazy and skipped ahead as I wanted to play )

I'll see if that fixes this weird 6 line thing and report back too.

thanks for your help.

Not a stupid question at all.. although when the object was at the top of the screen I didn't notice it as it looked like it was just clipping off the top of the screen. When I moved it into the middle of the screen was when I noticed the top 6 lines were missing.

I checked and it seems to occur on different sized objects. I have a 320x200 image I used for testing which is a photograph, and I subtracted 6 lines worth from the start address before inserting it into the object list, and it showed 6 more lines at the top of the image too!

For the data portion of the bitmap object, all I am doing is masking off only the bits I need, so assuming the object address is in D0

and.l #$3FFFF8,d0

Then shifting it into position

lsl.l #8,d0

this will get combined with the rest of the long word with or.l before being written to RAM

I have dumped the object list that is built and checked it out with a programmers calculator to ensure the bits all make sense and reference the correct addresses. If the address is left as the actual address of the bitmap, 6 lines go missing. If I subtract 6 lines worth of data from the address then I get the full object.

A thought just occurred to me…

I recall reading somewhere that you have to have at least 2 objects in the object list or the OP can become upset, this is usually two branch objects at the start of the list that essentially frame the screen. My object list at the moment is just 2 16bit bitmap object and a stop object. Could it be something weird happening because I do not have the branch objects at the start perhaps?

Unfortunately I am at work at the moment and have no access to my code or Jag

thanks

Don't know, I cannot test as neither seem to want to run on Windows 7.

I have hacked a work around in my list gen code. Takes the dwidth value of the object, shifts it left 3 bits and then multiplies it by 6, so far works. But seems really bizarre.

I guess you have never had this issue with your own object code?

I have only just noticed this Developer section! OOPS!

anyway.

More playing and I am now drawing something a bit more exciting than a blank area of RAM on the screen, I have a 32x32 16bit RGB object. It displays fine, except that the OP seems to jump ahead about 6 lines into the object from the start address I am giving. If I pad the start of the object with 6 lines worth of nothing I get the object displayed correctly. Likewise if I adjust the object list routine to subtract 384 from the start address of the object it renders correctly.

I have checked the address of the data in RAM and compared this with the constructed object list and it all looks fine. I even tried tweaking the object list creation code to shift the address one bit more and one bit less to make sure I hadn't screwed up there and the broken gfx proved I hadn't.

I just tried with a 320x200 image and that also loses lines off the top. (I have vague memories of something like this way back in 2003.. but not looked at it in earnest )

any ideas?

ARGH! I am an idiot! Matmook you got it in one! I owe you a pint

When I posted to the forum I was at work and not able to see my code, I just checked and sure enough there was no end comment.. GAH I am such a dumbass! it must have been another source file where I had that problem.. I blame being tired when I wrote it

Thanks again guys. I'll learn one day

Have you, at the end of the included source file a carrier return ?

ALN/MAC will not take the last line of included files if there is not a CR/LF.

 

If it's the case then "rte" will not be included...

Thanks, alas yep. That bug has got me a few times already, I have started putting a comment at the end of my source files that just says END to make sure I don't get bitten by it

Think I may try recreating the file incase there is something weird in there.

thanks again

OK if I actually copy the code into the same source file it works under a new name. But if I include a source file with the code in it doesn't work!

WTF!?

Hi,

Wondered if you guys could help my sanity a tad.

I have working code (yay) nothing special it sticks a bitmap on the screen.

Working on a few other bits and pieces I decided to tidy up my source files. I have a source file for each key job of my code, which are all assembled into objects and then linked together to form the ABS file. Now, my Vertical Interrupt rout had ended up in amongst my object list code, all working fine and dandy, but I thought really that shouldn't be there, I'll move it to somewhere else. So I did.. moved the code, copy and paste to a different source file, changed its name, updated my VB setup code to reflect the changes etc.

Now it doesn't work!

I have tried everything I can think of. The lines of source are identical,

I have changed its name to be the same as the original (commenting out the original) still nothing

I have included it with a different name to the same source file as the original, nothing

I have set error messages on the CPU error registers just incase it was blowing up for some reason.. nothing

Checked the memory address of the two routines.. working one is $2a710 none working is $2a730 both look fine to me.

All the VBI routine is, is:

movem.l d0-d6/a0-a6,-(sp)

jsr copylist

move.w #$101,INT1

move.w #$0,INT2

movem.l (sp)+,d0-d6/a0-a6

rte

which is identical in both places.

any ideas? some wacky bug in the Jag I have tickled? or ALN or madmac?

thanks in advance

Oh bum...

I doubt I would be anywhere near good enough to contribute anything worthwhile.

Out of morbid curiosity though.. what are the rules regarding such a challenge? Are you allowed to use your own library routines? (say startup code, object list code, joypad reading code)? or do you have to code everything from scratch ?

Cheers guys, couple of options there. I was thinking of the dosbox route myself actually

Want to steer clear of any old skool methods due to the added faff

Cheers Fadest, I will have a stab at compiling them and see how they work for me. Worst case I should be able to use dosbox and madmac/aln anyway so I should be good. Looks like I may have something to keep myself entertained at AC2011

Just had a sneaky google for them (at work ) and it seems Belboz was going to post OSX Universal binaries on the thread over at AA, but the last post is a few years old and doesn't look like they ever got posted. Did they get made? are they out there somewhere?

That would be perfect, erm, where can I get the source of those?

Cheers.

Hi

I have the coding bug back (YAY) and am likely to want to bring some with me to play with at events etc. However my current laptop is a PowerPC based mac. I have JCP compiled for OSX so can upload my code to a SkunkBoard, but at present I don't have anyway to assemble or link on my mac.

Is there an OSX assembler/Linker out there for PowerPC? or one with source that I can compile? would prefer to run it native rather than add an emulation layer.

Thanks in advance.

Looking like myself and some other intrepid explorers from the UK will be there this year

That is/was a most epic beard!

*IS* I still have it… in a jar

not quite as vibrant anymore tho

Yea! Mug the thug we'll have to call him now And there's nothing wrong with having had a Spectrum... can't say the same for the long hair & music taste of a certain gentleman to my left

ahem!

I am the one on the right! (although that was a few years ago)

\m/ MEEETTAAAAAALLLL!!!!

Good review squire, certainly was a blooming good weekend, biggest down side was the noxious fumes we had in the car on the drive home.. Think we have a contender for the roof rider next year

One thing that I wondered about doing this myself is if leaving the memory bus open and unterminated would possibly cause issues at high speed due to reflections on the bus from the unterminated end of the bus.

has Anyone who has done this seen odd behaviour ?