Jump to content
IGNORED

A Coleco ADAM programmer has some questions


LoTonah
 Share

Recommended Posts

Hi,

 

I'm learning how to do a bit more with my Coleco ADAM computer, but I seem to be running into a few walls. One of them is to do with graphic programming.

 

As you may know, the ADAM uses the same video chip as the TI. So I'm wondering what tutorials/books/utilities you guys depend on to get things done. I would prefer that the utilities run on OSX, but I also can run Windows, DOS and Linux software (albeit a bit more cumbersome).

 

Thank you!

Link to comment
Share on other sites

Cool! That's actually quite helpful. I've seen a few character editors on the ADAM, but they are quite a bit more primitive than this.

 

One thing I've always wondered about is any programs on the TI that push the VDP beyond its limits...more colors, higher resolutions, etc. It seems like every other system that I've seen has had programmers figure out how to break out of the limitations of their video chipsets, but the TI really hasn't.

 

I'm going to dig into that list a bit to see what else can help. Thanks!

Link to comment
Share on other sites

One thing I've always wondered about is any programs on the TI that push the VDP beyond its limits...more colors, higher resolutions, etc. It seems like every other system that I've seen has had programmers figure out how to break out of the limitations of their video chipsets, but the TI really hasn't.

Seen from a far and on closer inspection, that is probably true.

 

Do not forget TI Invaders, Parsec, Donkey Kong, Moon Patrol ... and the list goes on.

 

Most unexpanded home computer systems had user-access to the machine code level. That wasn't so with the TI. You could go there, but would at least have to get the relatively late and expensive Mini Memory and an extra manual or book. Anything you made wouldn't run on the unexpanded TI. Only recently a way was found to escape the sandbox.

 

3rd party games for the unexpanded TI released on cassette were relatively slow and unimpressive compared with what emerged on other computers of the era. You'll notice when you visit friends and experience other computers.

 

The above combined with several other factors *) only left a fraction of diehard fans. They did however push the VDP. Only in recent years has Asmusr made bigger and more impressive games and demos using tracker music and scrolling.

 

The TI sold in the millions and I guess only a small percentage of these were expanded with the Memory Expansion, Disk Drives, Peripheral Expansion Box etc. And that was what you would need before the millennium if you would want to push the VDP in the sense of a "demoscene". Again, anything you made wouldn't run on the unexpanded TI (the exceptions were few and very rare). This is a major difference between the TI and the competing computers with respect to exposure etc. Many jumped ship at least in Europe with the arrival, possibilities and activity surrounding the Commodore 64 and Amiga.

 

*) Closed architecture, restrictive and internal politics, shoehorn design, sold well when price dropped but then with no profit, locking out Atarisoft games, pulling out of the home computer market etc.

 

;)

Edited by sometimes99er
Link to comment
Share on other sites

To see the VDP pushed beyond its limits, you need to look at the MSX community, so far, they have pushed it the hardest. :) (Be aware that demos on an MSX2 have a more advanced video chip).

Yep. And the ColecoVision didn't do bad either showing off the possibilities of the VDP, with about 145 game cartridges for the system between 1982 and 1984.

 

:)

Link to comment
Share on other sites

To see the VDP pushed beyond its limits, you need to look at the MSX community, so far, they have pushed it the hardest. :) (Be aware that demos on an MSX2 have a more advanced video chip).

 

It could be interesting to port the MSX2 stuff to the Geneve or to a TI with 80-col card. :)

  • Like 1
Link to comment
Share on other sites

I'm learning how to do a bit more with my Coleco ADAM computer, but I seem to be running into a few walls. One of them is to do with graphic programming.

 

Way back I read about and liked the ADAM very much. Never saw it though. Is said to have had some problems and sold less than 100,000 units.

 

Not to drive you away or anything, but do you know about this forum ? ;)

Link to comment
Share on other sites

The TI chip in the CV/ADAM has a bug where if you plot a point withing 8 pixels of another point, it takes the color of the first point.

Still, the programmers were able to do some snazzy things. To this day I don't know how they got by the limitation in the end game graphic in the 2010 text adventure.

Link to comment
Share on other sites

It could be interesting to port the MSX2 stuff to the Geneve or to a TI with 80-col card. :)

The end result would be interesting, but porting cycle-counted Z80 code to the Geneve might be a bit of a mission. ;) (And if the Geneve doesn't use a common clock between the CPU and the VDP, may be very difficult -- some of the demos rely on being able to run in lockstep.)

 

The TI chip in the CV/ADAM has a bug where if you plot a point withing 8 pixels of another point, it takes the color of the first point.

 

Still, the programmers were able to do some snazzy things. To this day I don't know how they got by the limitation in the end game graphic in the 2010 text adventure.

It's not bug, it's a feature! ;) Bitmap mode is actually still character mode, the designer just managed to find enough memory cycles to be able to pull up extra character sets and a different color on every scanline. But you're still limited to two colors in a character cell, which is 8 pixels wide. (He actually developed it after the chip was first put into production, that's why the 9918 doesn't have bitmap mode, but the 9918A does. ;) )

 

Have a look at my graphics converter here: http://harmlesslion.com/software/convert9918

 

You can do some pretty nice things even with those limitations. :)

  • Like 2
Link to comment
Share on other sites

 

Way back I read about and liked the ADAM very much. Never saw it though. Is said to have had some problems and sold less than 100,000 units.

 

Not to drive you away or anything, but do you know about this forum ? ;)

 

It is true. From my own experience I had to return my first ADAM to the store and get it replaced with another one. Every other glitch that seems like myth now actually happened to me personally (erased tapes, data drive lock-up, etc.) But, and maybe I just like an underdog, I stuck with it and its been a lot of fun. Units made later on were pretty solid.

 

Yes, there were only around 100,000 units made, but if you count in the ColecoVision, there are more than a million of those.

 

Yes, I'm in that forum all the time. There are a few ColecoVision programmers talking in that forum. Honestly though, there isn't a lot of information being shared by these programmers and there isn't a lot of pushing the limits of the machine happening either. Most of the "innovation" happening seems to be due to having larger ROM sizes to work with or relying on OpCode's Super Game Module. No offense to any of those people, they're great people. I'm just looking for a bit more than what they can provide for me.

 

I mostly want to work on ADAM software, not ColecoVision games.

Link to comment
Share on other sites

On msx one of the most interesting examples of use of the vdp is this

 

 

It does not relies on cpu/vdp synchronization, but on some undocumented features of the vdp about the reuse of the color sets for different banks.

 

On msx2 instead, despite of the lack of hw horizontal scrolling, it is possible to do this, in screen 8 (256 colors)

 

 

This latter is just a wip (I reused Amiga graphics), the former is a complete game.

Edited by artrag
  • Like 2
Link to comment
Share on other sites

 

Yes, I'm in that forum all the time. There are a few ColecoVision programmers talking in that forum. Honestly though, there isn't a lot of information being shared by these programmers and there isn't a lot of pushing the limits of the machine happening either. Most of the "innovation" happening seems to be due to having larger ROM sizes to work with or relying on OpCode's Super Game Module. No offense to any of those people, they're great people. I'm just looking for a bit more than what they can provide for me.

 

Don't be shy to show your works ;)

 

Myself I've answered a lot of programming posts and even published the complete source code of one of my games http://atariage.com/forums/topic/245296-zombie-near-source-code/, I don't see any questions from you in the Colecovision Programming forum.

 

As always use highly-compressed graphics and music in my games (typically compressed with Pletter, a damn good compressor), if you see a "larger" ROM size is because my games includes a lot of graphics and music ;)

  • Like 1
Link to comment
Share on other sites

One thing I've always wondered about is any programs on the TI that push the VDP beyond its limits...more colors, higher resolutions, etc. It seems like every other system that I've seen has had programmers figure out how to break out of the limitations of their video chipsets, but the TI really hasn't.

Actually you can't have a program that pushes the VDP beyond its limits. One may however perceive that something appearing on screen would otherwise seem impossible. And I can understand if someone chooses to disagree. Yes, you can do something that hasn't been done (or seen) before.

 

We may think that the VDP has a certain limit, and then suddenly discover something that goes beyond that limit. But in fact the new discovery has still to be within the limits of the VDP. Otherwise it won't run / show.

 

What the designers may or may not have envisioned as limits, or what we think was the limits, is perhaps relevant, but also guesswork. Hindsight is wonderful and relative. We live in another time with different perspectives and knowledge - and holes in the cheese. Time or evolution has found ways to explore or benefit from maybe "thinking out of the box", or in essence, to "break the limitations" by shear creative imagination, - or inspiration, copying, cross-work, putting different things together, or by divine / random intervention.

 

Often when you see an effect and go, wow, how the h*ll did they do that, - then later you'll go, oh, I see, nice trick.

 

Rant stop.

 

;)

Edited by sometimes99er
  • Like 1
Link to comment
Share on other sites

 

Don't be shy to show your works ;)

 

Myself I've answered a lot of programming posts and even published the complete source code of one of my games http://atariage.com/forums/topic/245296-zombie-near-source-code/, I don't see any questions from you in the Colecovision Programming forum.

 

As always use highly-compressed graphics and music in my games (typically compressed with Pletter, a damn good compressor), if you see a "larger" ROM size is because my games includes a lot of graphics and music ;)

 

I've offended you. I'm sorry, I didn't mean to--I've admired your work for a long time, the CoolCV project is great stuff.

Link to comment
Share on other sites

Commonly perceived limits and physical hw limits differ. LoTonah was referring to rise the former toward the latter

Yep, probably.

 

Many things that have been said to be "a first" (on this forum and said in good faith), turns out to have been preceded. With thousands of games etc. available for the TI, of which I've only seen a fraction, I tend not to subscribe to "commonly perceived limits". As in, we all have our own versions.

 

;)

Link to comment
Share on other sites

You can safely stay sure that uridium on msx1 is a 'first' in the tms9918a scene.

It is using 1024 tiles (two pages of 512 each) to show the scrolling you see.

Not a single tile definition is updated during the gameplay, only PNT data.

Edited by artrag
  • Like 1
Link to comment
Share on other sites

You can safely stay sure that uridium on msx1 is a 'first' in the tms9918a scene.

It is using 1024 tiles (two pages of 512 each) to show the scrolling you see.

Not a single tile definition is updated during the gameplay, only PNT data.

No question, uridium on the msx1 looks impressive.

 

The "perceived limit" of "a good chunk of the screen scrolling horizontally and some sprites" has been seen before on the 9918a.

 

;)

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...