Xump (Retroguru) for 2600 WIP port and presentation

[Nop90]

Hello,

 

I use to be active in the Atari Lynx section, but the 2600 was my very first console so last week end decided to try to code something for it, and since I'm one of the coder of the Retroguru Team, I started to port a game of ours that I already ported to other consoles, included the Atari Lynx.

 

I'm not a 6502 ASM expert, but I code in ASM for the Lynx when I need to do things not possible in C, and I know the VCS achitecture because last year tried a crazy project to run 2600 code on the Lynx: obviusly I failed for lack of CPU speed - how I could hope to race a code that race the beam - but at least implemented a big part of the core of the system).

 

What I did do for this new project far was to collect a lot of 2600 code snippets and assemble them to have basic rendering core and enough free ram to be able to complete game logic.

 

This is what I did in a couple of days of work:

 

 

 

I added 5 different levels that can be changed with the select switch. The level can be reloded with the Reset switch (losing a life in the final game).

The player can run along all the level screen with 4 different sprites (for the 4 directions), now I have to add the logic to remove the tiles after stepping on them and check if xump goes out of the path. Should not be hard because the worst part was to draw the screen, the other things goes in the VBLANK.  

 

I should have a tech demo to show in a video in one or two weeks (I also have to work other lynx project so can't code on this every day), but at the moment really don't know how to add the missing elements of the game like the bombs and the one way tiles because I have only two cycles left in the scanline rendering routine of the level.

 

I think the result so far is promising. The GFX guys of the Retroguru Team are complaining that they don't like too much the screen layout, but they grew up in the Amiga era and can't understand the lack of a framebuffer ?.

 

Every hint to make the playfield look better is welcome.

 

I really hope to make something playable from this. I like to solve coding issues on my own but If I really need help I'll ask here.

     

     

[gorgh]

nice one! yt video would be appreciated

[Nop90]

The level logic for simple tiles is complete and also added a level timer. I have only to fix the position of the score numbers to have it in center (tried to do it but made a mess witht the timing, probably I'll write it from scratch instead of trying to adapt the code snippet I used).

 

 

 

The level drawing is very tricky, so much that adding the bombs on the tiles seems impossible. But I don't give up.

 

Don't know hot to make a video, does Stella has a video recording feature?

 

I could record with my mobile the game on a TV, but I used NTSC colors and I have a PAL 2600JR so the game colors are really ugly on it.

 

[gorgh]

If you use WIN10 then press windows button+G, and then yu can record given window

Edited May 4, 2021 by gorgh
typo

[Nop90]

As promised here is a simple small video of what I coded so far:

 

 

 

Level restarting/changing isn't in the game logic yet. I use the Reset/Select switches for the moment.

 

The code already reached 4KB, so before the next update I have to select the best bank switching strategy to use.

 

Meanwhile @miker made a nice conversions of a couple of Xump music tracks with Tia Tracker. Probably now I'll start coding the title screen and the menu screen with one of the tracks as background music.

[gorgh]

thanks a lot Gisberto!

[Nop90]

Today coded the Retroguru splash screen and a mockup of the title screen (upper part will be also used for the menu).

 

 

 

I'm not very good with graphics, but I'll ask some help to the gfx guys of the team to improve the overall look.

 

[+bhall408]

On 5/6/2021 at 4:19 PM, Nop90 said:

Today coded the Retroguru splash screen and a mockup of the title screen (upper part will be also used for the menu).

 

Nice! Does the guru do the floating animation and make sounds like the version on Lynx?

[Nop90]

The sound, yes. At least I have It as a TTT export and will be played as soon as I complete to reorganize the code in banks so to have space to place the Tia tracker engine in the main bank.

 

For the floating part I'll try. With a 48 px sprite not only I have to adjust the x pos of the first sprite every frame but I also have to adjust the timing of the drawing routine. I'll try.

 

[+SpiceWare]

On 5/4/2021 at 8:56 AM, Nop90 said:

The level drawing is very tricky, so much that adding the bombs on the tiles seems impossible. But I don't give up.

 

How many bombs do you need to add?  You can use NUSIZx to duplicate and triplicate the other player for up to 3 bombs per row, though spacing is limited to preset options of close, medium, and wide.

 

Vertically you can reuse the other other player by repositioning it. Your gaps between rows of blocks should give you enough time for repositioning.

 

 

I noticed in the video your current repositioning routine causes an extra scanline to show up when the player gets to the right side. That'll cause TVs to jitter the image. This might help you with that, along with vertical repositioning:

 

 

 

4 minutes ago, Nop90 said:

With a 48 px sprite not only I have to adjust the x pos of the first sprite every frame but I also have to adjust the timing of the drawing routine.

 

MiniDig can be a useful resource, it's a collection of the best of the old Stella mailing list. Under tricks you'l find 48 Pixel Sprite with links to source, ROM, and the original post it came from.

Archive of the Stella mailing list from 1996 to 2006 can be found here.

 

 

[Nop90]

this is how I'm going to implement bombs

 

 

they work fine in the left side of the screen or in rows without fixed platform, but there is no time to switch to solid gray near the end of the scanline, so I'll have to design new levels considering this limits.

 

The teleport platforms should be an easy element to add. Probably I will not implement the one-way tiles.