New Game in progress: Castle Rex

Wilson · Post by **Wilson** » Mon Sep 28, 2009 8:21 am

I meant to have a demo of this game ready in time for ECCC, but the day before ECCC I found out that it only worked in VICE with true drive emulation disabled. As a result I had nothing to show, but I have resolved the issue and tested the game with true drive emulation and on a real vic-20 with a uIEC.

The name of the game is Castle Rex. It is a point-and-click adventure for the unexpanded vic-20. It is a multi-file machine language game somewhat inspired by my favorite point-and-click adventure, Shadowgate, but a number of design changes have been necessary due to hardware... differences.. I'm hoping to finish by Halloween, but I'm only going to release it when I'm satisfied with the quality so it could be as late as the end of November by the time I finish. I can't even promise that it will be done by then however.

This is a screen from the game. This isn't the final version of the picture, and obviously the text is just placeholder right now, but it gives you a basic idea of what the game is like.

orion70 · Post by **orion70** » Mon Sep 28, 2009 8:54 am

Cheers Wilson, and welcome to the forum

.

WOW! Something tells me that I'll keep reading this thread over the coming weeks...
Some preliminary questions

:
- Will it be a strictly D&D fantasy setting? No hope to see something different (e.g., a post-nuclear war setting, or sci-fi)? Not that I don't like the fantasy genre, but there have been many VIC releases recently with this setting (1 2 3 4)

.
- Will it be a point and click adventure in the classic SCUMM style? If so, will it be joystick-driven?
- Released for disk I guess, but how much free RAM required?
- As I see from the screenshot, it looks like an almost monochrome game- or is it only the mockup?

Keep up with it, I'll go buy my Halloween pumpkin tonight

.

Wilson · Post by **Wilson** » Mon Sep 28, 2009 10:25 am

Cheers Wilson, and welcome to the forum.

Thanks!

- Will it be a strictly D&D fantasy setting? No hope to see something different (e.g., a post-nuclear war setting, or sci-fi)? Not that I don't like the fantasy genre, but there have been many VIC releases recently with this setting .

The setting is fantasy, but the mood is very different from those other games. It doesn't take itself seriously at all. I have already designed the picture data for almost all the rooms (over 40 of them!), so drastic changes would be quite painful.

- Will it be a point and click adventure in the classic SCUMM style? If so, will it be joystick-driven?

It is joystick-driven, but it has no scripting language or anything. When this game began it was just going to be a quick project (one month tops), so implementing something like that seemed unnecessary. Now to keep compatibility, I'm using a pretty poor system (from a programming perspective). Things like items that can be taken and doors that can be opened are handled, but other things must be programmed on a case-by-case basis. I'm definitely interested in making an easier way to make games of this style in the future, however.

- Released for disk I guess, but how much free RAM required?

Yep, the game is disk based. Right now I'm pushing the unexpanded memory, but the game will not go beyond that. It will run on an unexpanded vic-20.

- As I see from the screenshot, it looks like an almost monochrome game- or is it only the mockup?

It is not a mockup. The room I chose probably wasn't the best example of what most rooms are like. The game does have color. All the graphics are designed for 8x8 characters though, so multi-color chars are never used.
Here's a better example of the average room:

Keep up with it, I'll go buy my Halloween pumpkin tonight .

.

orion70 · Post by **orion70** » Tue Sep 29, 2009 4:11 am

Wilson wrote:Right now I'm pushing the unexpanded memory, but the game will not go beyond that. It will run on an unexpanded vic-20.

This will please our Denial founder

. All jokes apart, I think that a multi-room disk game for the unexpanded VIC shows once more how much could have been done to exploit its possibilities when it was commercially profitable. Where were you back then?

darkatx · Post by **darkatx** » Tue Sep 29, 2009 7:20 am

I, for one, am impressed with the look and the unique gameplay this game affords.
If it could be done unexpanded even better...

IsaacKuo · Post by **IsaacKuo** » Tue Sep 29, 2009 7:43 am

How do you feel about using the ROM font instead of a custom font? That would free up a whopping 1K of RAM. Plus you could use unreversed PETSCII graphics for free.

You use POKE36869,255 to use a mixed custom/ROM font where 0..127 are custom characters from 7168...8191 and 128..255 are the first 128 ROM characters. I wasn't aware of this trick back in the old days.

Wilson · Post by **Wilson** » Tue Sep 29, 2009 1:42 pm

IsaacKuo wrote:How do you feel about using the ROM font instead of a custom font? That would free up a whopping 1K of RAM. Plus you could use unreversed PETSCII graphics for free.

You use POKE36869,255 to use a mixed custom/ROM font where 0..127 are custom characters from 7168...8191 and 128..255 are the first 128 ROM characters. I wasn't aware of this trick back in the old days.

A good idea, but that only gives you 64 custom characters doesn't it? (512/8=64). I'll think about it. Perhaps I could switch out to the ROM set when the raster beam gets done with the picture too. I've never tried that though.

darkatx wrote:I, for one, am impressed with the look and the unique gameplay this game affords.
If it could be done unexpanded even better...

Thanks. Even if this game ends up in the Worst VIC game thread, it will at least have unique gameplay

. I'm glad you're alright with the look of the game. After playing a lot of vic-20 type-ins I really like rough visuals. Though I suspect they will not appeal to everyone.

orion70 wrote: Where were you back then?

I wasn't born yet.

IsaacKuo · Post by **IsaacKuo** » Tue Sep 29, 2009 1:47 pm

You can have 128 custom characters if you also move the screen to 6656. Thus, .5K is consumed by the screen matrix, and 1K is consumed by the 128 custom characters. This consumes a total of 1.5K from 6656 to 8191, leaving you 2.5K in "main" memory from 4096 to 6655.

Wilson · Post by **Wilson** » Tue Sep 29, 2009 7:35 pm

IsaacKuo wrote:You can have 128 custom characters if you also move the screen to 6656. Thus, .5K is consumed by the screen matrix, and 1K is consumed by the 128 custom characters. This consumes a total of 1.5K from 6656 to 8191, leaving you 2.5K in "main" memory from 4096 to 6655.

Ah, I didn't even think about moving the screen. If RAM gets tight, I'll definitely implement this method. If not, don't worry, I will design a new font. The current comically bad one is just a placeholder.

Centallica · Post by **Centallica** » Wed Sep 30, 2009 7:33 am

Great game you made!!

I love Shadowgate on the Original Nintendo and now have it for GBC via GC on my plasma!

The music both got eerie and on your neves after a while in Shadowgate, but I think it added to the experience!

Hope to give this game a twirl someday on the Vic!

Ghislain · Post by **Ghislain** » Sat Oct 03, 2009 9:19 am

orion70 wrote:- Will it be a strictly D&D fantasy setting? No hope to see something different (e.g., a post-nuclear war setting, or sci-fi)? Not that I don't like the fantasy genre, but there have been many VIC releases recently with this setting (1 2 3 4) .

There can never be too many D&D games for the VIC-20

Looks impressive! Can't wait to play it.

adric22 · Post by **adric22** » Thu Nov 05, 2009 10:14 pm

IsaacKuo wrote:How do you feel about using the ROM font instead of a custom font? That would free up a whopping 1K of RAM. Plus you could use unreversed PETSCII graphics for free.

You use POKE36869,255 to use a mixed custom/ROM font where 0..127 are custom characters from 7168...8191 and 128..255 are the first 128 ROM characters. I wasn't aware of this trick back in the old days.

Actually, I was unaware of this. I just recently read the VIC-20 Programmer's reference guide and it specifically said this was not possible and that it was an all or none situation when it came to moving the character set.

carlsson · Post by **carlsson** » Fri Nov 06, 2009 5:06 am

I suppose it depends whether you consider the ROM font as a form of custom graphics or "normal" characters. You can't mix normal with custom, but thanks to a wrap-around effect in how the VIC-I reads the memory it fetches additional custom graphics from the ROM.

Mike · Post by **Mike** » Fri Nov 06, 2009 5:42 am

adric22 wrote:
IsaacKuo wrote:How do you feel about using the ROM font instead of a custom font? That would free up a whopping 1K of RAM. Plus you could use unreversed PETSCII graphics for free.

You use POKE36869,255 to use a mixed custom/ROM font where 0..127 are custom characters from 7168...8191 and 128..255 are the first 128 ROM characters. I wasn't aware of this trick back in the old days.
Actually, I was unaware of this. I just recently read the VIC-20 Programmer's reference guide and it specifically said this was not possible and that it was an all or none situation when it came to moving the character set.

IIRC, the manual refers to it not being "possible" to show both upper, and lower case character sets displayable on the screen at the same time. On page 267:

Programmers' Reference Manual wrote:"The two character sets are available, but only one set at a time. This means that you cannot have characters from one set on the screen at the same time you have characters from the other set displayed. [...]"

Of course they didn't take into account, it's quite well possible, using a (simulated) raster interrupt.

Michael

Edit: In the meantime, I also found the paragraph you were referring to. It's on page 84:

"Generally, if you use your own character set by telling the VIC chip to get the character information from the area you have prepared in RAM, the standard VIC characters are unavailable to you. [...]"

... which, as we know, isn't correct either.

adric22 · Post by **adric22** » Fri Nov 06, 2009 8:13 am

Mike wrote: ... which, as we know, isn't correct either.

I found some other errors in that manual as well. One that stands out is there was a place where they were talking about the different locations for controlling the various "speakers" on the VIC-20 (I guess they didn't call them voices back then) But anyway, some of the memory addresses were wrong. I think they had the white noise mixed up with a regular voice.. but then on a different page where they were mentioned again, they had it right.