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Dino Eggs revisted

Captain Cozmos

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I am working on merging the code I created over the last year into a new DEMO.

In the mean time I wanted to get your opinion on which one looks the best.


The Commodore 64 version seems to be the best version because it is completed but I tend to think my version is the most updated and colorful.

You tell me...


DEApple2.thumb.png.82eb067b818f5f6c622d219801d7c6b5.png The original Apple 2


DEPCDOS.thumb.png.4ad2db9245be8c73212a375509b055c6.png PC DOS


DEC64.thumb.png.a8d0fde44a17cf590adf2ca707214d7c.png  Commodore 64


DEColeco.thumb.png.0536e7eb0a0f0003c68e5bdff60e6dfa.png Colecovision (my version)


The credit Tablet at the bottom is higher than the others because it will take two credits and copyright.

Mine and Schroeders.  I plan to make it wider at least 16 bytes on each side.



Feel free to comment



Edited by Captain Cozmos
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I prefer your version for its colorfulness over any of the others. However, perhaps you could model the credits tablet after the C64 version. It still lists two names, and isn't as high, and yet is also wider by at least 16 pixels per side. Also prefer the view of the sun / moon above the bedrock, instead of merely grass as in your version.


The CV allows a full 16 colors, while the Apple II only allows 4 true colors in high-res mode (280x192).

Edited by zyzzle
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I am working on my official Dino Eggs Tech Demo.


So far I have merged all of the features that I think should be in such a thing as well as updated a tremendous amount of old code with new techniques.


The scrolling text was the hardest to achieve and when I wrote the routine in long hand it was 22k.

After I rewrote the routines in a fashion that was compressed and did not impede function, it was a bit over 7k

That is to include a lot of code that will be universally used so if I ever do make a game it should all fit together within a 32k binary.



Now for a bit of retrospective.


This is not an Apple or a Commodore 64.  It's not an Atari or a DOS Machine.  It is a Colecovision that uses 8x8 patterns, 1k of memory, no real scroll capability and 4 sprites per line.


After trying to get this to work using modern tools I personally believe that this would have never been released back in 1983.  You can call me out for that statement and I will defend it.


If you look at the pace of working on those games, the machines and other factors.  Dino Eggs was not getting released.  Again, this is my opinion based off what I have been doing.

There was trial and error along with enormous amounts of data with precise coupling of the video I/O ports in order to achieve a smooth scroll within the NMI.
My bitmap scroll has to actually be slowed down and it is a 1 to 1 scroll.  This does not move every 2 pixels, it scrolls 1 pixel at a time up or down the screen.

After I merged a table system with a bit of math and the IO ports...along with a bit of help from MacCallan, I got it working.


I used some of this direct access my previous pattern demo where I had 60 individual patterns on the screen at once that could move in any of 8 the directions.

The only limitation was the Colecovision memory.  Video and System.


In this Demo's case, I have to juggle a merge between Bitmapped and Patterns on one screen.  Otherwise it would have to be all patterns or all bitmap.



So, everything is in play to get the demo out before Christmas, right now I am working on making the scrolling Tablet look better and with credits.  Then comes sound.

Everything else is pretty much done other than optimization.




Question:  If you had to scroll an amount of text up the screen then how would you do it.

The Dino Eggs banner is 48 lines (blank lines included) and 16 individual characters wide.



03 Cosmos

Edited by Captain Cozmos
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Are you not entertained...........




This also works on a stock Colecovision, real hardware...tested.  Full speed, no mods.


Up till now has been a fight for VRAM space because of the bit mapped area and what is to be expected on the screen up until the scroll effect is completed.


After the scroll is done, I can reclaim space with a simple call but this one has been a frustrating journey.





03 Cozmos

Edited by Captain Cozmos
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I'm shutting work down for the Christmas and New Years season... I may drop by for greetings but I really need to do other things at the moment.


Until then, here was the last work I completed on the Dino Eggs tech demo.


Now, this is not to say I am working on the real game.  I have yet to reach an agreement with Mr. Schroeder.  He is more than agreeable in allowing me the freedom I need but I feel that we are not there yet.


I am not going to debate this in the public square.  But I will go as far as far to say that I wrote some brand new technology which allows this 40 year old game to run on the Colecovision that otherwise would not.  At least not the way it did on all other ports.  I am going to be very protective of that tech hence you are watching video's and not getting a rom that will just end up in the ADAM archive.


If we do reach an agreement then this will go into the port of Dino Eggs that I have worked on for the last couple of years.

Now, if the project is "acquired" by some other enterprising programmer then let them figure out the last two years of my research instead of disassembling my rom and taking it.  This has happened to me in the past and I will not give them the opportunity to do it again. 


In any case and without further yak yak yak.

Here is a video of my latest work.  Enjoy...



03 Cozmos

Edited by Captain Cozmos
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2 minutes ago, zyzzle said:

Wonderful! The scene above completes the timewarp perfectly. We have an early, primordial sun and backdrop to add so much more to the Dino Eggs vibes.

I am rewriting the falling tablet in order to free up more pattern space so I can make the top graphic look even better and diverse.

The new tablet will look closer to the original when I am done.

Edited by Captain Cozmos
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29 minutes ago, youki said:

Is There already some gameplay coded? Or just what we see on the video?

I already released the 1st stage platform as a tech Demo where the main character walks around, jumps, climbs the rocks.

I even coded in the ECB so when he goes off the screen to the left it's the same as if he was going off the screen to the right.


This latest video is the background story with falling tablet.  That scrolling text was a pain in the &&& if I have not mentioned it already.

I've already updated it from when I published that video to use less tables and resources so it comes in from 21 to less than 10k.

If I ever do make the whole game it will use elements from both plus I have expanded my programing talent since whenever I started the first Dino Eggs rom.
This is the byproduct of disassembling countless games and finding out how the professionals did it.


Sooner or later I will go back to my older work like Haunted House.

Of all things the only routine holding me up is the candle light.  Easy to do on the Atari 2600, hell to replicate using patterns on the Colecovision.

Just imagine the math on trying to use that candle on a scrolling screen.  It was giving me a headache which I did not need at the time.

Edited by Captain Cozmos
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Great progress. Things I liked:

- Level design and especially the top "prehistoric" look

- the fluidity of motion - precise response. And very smooth transitions in movement

- That Tim moves fast



- Perhaps make Tim not jump as high. His head "touches" the top of the next level. Lower it to a couple of pixels below the very top.

- I presume the colors of the levels will match the original (level 0,1,2 = red, 3,4,5 = blue, 6,7,8 = green, 9 = purple / night time)


Thanks for posting your latest demo. 

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I am rewriting a lot of this and it will make it Stronger, Faster, Batter  plus it will not cost Six Million Dollars for those old enough to remember that show.


I wrote a new routine, 100% mine.  I did not find it somewhere.

This routine flips the sprite, pattern or table in vram.  So now I only have to come up with half of all my patterns sprite or otherwise.

Now you say, Cap'n,  That has been around forever.  Yes it has but I have never found it on the Colecovision or code for it.

Again, you say...but Cap'n... There are BIOS routines that will do that.  Yes, but there is setup, overhead and a lot of it relies on the delayed write routine as well as a lot of other factors.

It's a bit of energy to create software that uses both Coleco Engineer format and your own design.  Also, my routine is faster and uses less space.  It is also more versatile.


BTW... You don't have to use "INIT_TABLE to setup the tables.  All this does it set an entry up near the stack that all the other table based routines use.

I've used:

    LD A, $38
    LD ($73F5), A


Instead of this:

   LD A, 1
   LD HL, $3800


With no issues.


In any case.

My routine grabs a portion of vram to a buffer then flips the patterns before sending it all back from where it came, or where you want it to go, all in a split second.

It can be expanded to any size, 8x8, 16x16, pattern table, sprite table, color table.



Edited by Captain Cozmos
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Reworked the Scroll Table using the Stack Pointer and some addition math.


Now the Scroll Demo is at under 6k.

Combine that with the full Demo code it comes to around 11k before sound.


I highly recommend that people start reading and studying source code if you want to create these games.

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Just adding to the record.


I highly recommend that you stay in school, learn some math if you plan to program.  Especially in Assembly.
Yes, the assembler does a lot of the work but if you figure a bit of math then you do not need all of those tables because in reality 99% of the Coleco world is in multiples of 8.


So when I finally got the scroll portion working I ended up with a 21k rom.  I wrote it all in long hand then optimize later.

Being as that we use modern computers and not some old HP terminal it is easier this way.


I have continuously said that this game would never have been made due to the complications.  It was not meant for this hardware.

Regardless, I have been able to use all the resources along with a lot of stack and direct addressing in order to trick the stock Colecovision into doing what I wanted.


In any case, this is just for prosperity and to show what some 8 bit math can do to reduce huge bitmapped tables.

I must have deleted my oldest rom but here is a comparison of the last 3.




If you want to write Colecovision games.

Study source code and ask questions.

Write, write and write some more.

If it doesn't work then who cares, start over.  Try a different approach nut just don't quit.


03 Cozmos

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  • 2 weeks later...

Keeping the thread alive.

I'm still working on this Demo but I am creating some new routines that is necessary for this and the Shamus Clone which has now morphed into something better than Shamus.
Speaking of, this new idea of mine is using the patterns code I already wrote and giving you a brand new game never created for the Colecovision.
I can still repurpose it for a 1 to 1 Shamus clone if I chose to.  I want to give you something different that will work on a stock system in either PAL or NTSC.

With that, I have come up with two new routines that allows you to buffer a 768 byte screen to ram, alter it, then send it to VRAM in real time between NMI's

The second one being I can mix multiple parsed cells in that RAM space and be scrolled.

So that could mean anything from one giant play field, several small dungeon cells, a giant picture you can traverse.
Now change my earlier pattern routines into walls then you get a scrolling dungeon crawler in 8 directions.
So after my other projects are completed who knows, Tunnels and Trolls?

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