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Irgendwer

STUNT CAR RACER?

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It *almost* makes me want to trade my A8 for a BBC! Except for the God-awful colors (and 1001 other things the A8 does better)...I'll just have to "settle" for a Rapidus I guess...

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Seems faster than the 16bit version to me.

Could belong to the "grid" graphics with low details. That was the cause why the C64 version looked playable once.

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Could belong to the "grid" graphics with low details. That was the cause why the C64 version looked playable once.

 

Indeed with higher resolution but there is a 68000 behind :-/

Although I grew up with the Amiga version, this looks like the DOS one with unlocked framerate.

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Interesting to see that the pure CPU speed is the relevant part to the shown fps.

Even by the "tricks" of using the character attributes for the sky, the C64 is exactly at half the speed of the BBC version.

The coder stated that the BBC has to handle everything bytewise in the graphics it offers.

So it seems, the character mode isn't really giving more speed. The benefit is the additional color of the sky.

The BBC Game Screen uses 4 colors.

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Even more interesting. Now that the BBC version is rewritten to handle the game in linear graphics, how much would be needed to adopt that for the Atari. Particular for a turbo mode in Antic D ?

I wonder if the 12fps could be topped.

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eMkay, you do know a couple coders, and you have some ideas, maybe you could get together with all and make it happen. Just to show what can be done. Nothing says it better than to have it in front of the eyes.

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Kieran Connell:

 

The BBC doesn't have a character attribute mode so the sky is filled by filling the screen pixels directly (so 8x bytes required per character.) Fortunately the BBC Micro has a faster 6502 CPU so we have enough time to do this (along with plotting the sprites in software and everything else that has to be done manually without the mighty VIC-II chip.) You can see the final results in the other video on my channel. More technical info on the Stardot forum and happy to answer questions at greater length there.

Edited by emkay

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No answer yet? OK, let's have a closer look there:

 

Even IF still the base of the code is handling character graphics, EVERY BENEFIT of character graphics is gone in the BBC version.

While the C64 is based on Character Graphics, supporting the faster drawing for the sky, on the BBC version now it is more a brake than an accelerator.

Stripping off the character handling would offer even more speed.

On the Atari the character mode steals a lot CPU cycles that would be better used for the 3d calculations.

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Even IF still the base of the code is handling character graphics, EVERY BENEFIT of character graphics is gone in the BBC version.

 

This has nothing to do (excluding the hardware simplicity aspects) with character graphics, it's just the way the screen memory is organized on the C64 and BBC: In character like cells.

Stating that "EVERY BENEFIT of character graphics is gone" shows again how less you know about programming. Even this "not natural" non linear screen memory organization can be used beneficial as it allows to control a quite compact local area of graphics.

 

Speaking 6502 here, to color the upper left cell area uniform you can do this (simplified) with:

       ldx #7
next:  sta screenmemory, x
       dex
       bpl next

While in a 40 byte linear screen memory scenario you leave the 8 bit offset after the 6th line (7*40 = 280 > 255), complicating the code and slowing it down.

I'm not saying that a cell based screen memory is better (often it's not), but if your code targets already the idea of such local cells (sky, ground) you can use that organization beneficial.

 

You would do yourself (and us) a favor, if you don't act like your statements reflect the absolute truth - they don't.

Edited by Irgendwer
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To add to Irgendwer's points, the difference between the BBC and the C64 is that the C64 includes the colour-map support and hence it can 'paint' a large area of character cells very efficiently whereas the BBC would have to write to the screen memory (and so has only the 4 colours available). However, I would imagine that is balanced due to the BBC Master making use of the additional instructions it's processor offers as they would also give a speed improvement.

Edited by Wrathchild
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Sometimes I do not wonder why the Atari never gets the missing software.

 

 

What a loose sentence:

 

Stating that "EVERY BENEFIT of character graphics is gone" shows again how less you know about programming. Even this "not natural" non linear screen memory organization can be used beneficial as it allows to control a quite compact local area of graphics.

 

We're not talking about a gamescreen where the relevant parts could be repeated or mirrored.

If the coder decides to use "clusters" for better handling of ranges of the screen, he has to re-calculate the screen buffer for the other stuff that is needed to be calculated. The screen needs to be build for constantly changing the whole screen buffer, to get the calculation linear.

The real benefit in the C64 version is to get the screen color by just setting the color information into a block of 8 bytes. This refers to the lines that build the border between the Sky and the Ground. On the BBS the Engine still calculates the 8 byte character range and changes the lines afterwards to get the Sky distinguished from the ground.

Comparing the C64 game to the CPC or Spectrum version, there is a clear indicator that the character mode doesn't speed up the game at 1st.

Edited by emkay

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39 minutes ago, xxl said:

you can put ATR on cartridges

nice feature 🙂

is there a 'how to' guide available?

sadly, the youtube channel has no further info about the procedure

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4 hours ago, xxl said:

update xB. you can put ATR on cartridges

Great, I'll check out your latest work with XB v4.

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Any way to get this running with a happy drive?  SIO2SD works, so does SIO2PC.... 1050 Happy drive doesn't work, even in unhappy mode.

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Oh you guys and all of this talk of increasing the fps when some of us just want a 5200 conversion and the use of a modded CX52 as a Paddle Controller for steering. Granted, we need a decent 128K RAM upgrade which nobody has done yet [to my knowledge]. 

 

I'm guessing the "easiest" way to get the fps up in A8 land would be to use the VBXE. Or the various 65816 upgrades. Or both. Of course, some would consider that "cheating". 

 

Didn't the Atari ST and Amiga versions of this game support null modem cable networking for head-to-head challenges? Or am I thinking of one of the 3 or 4 other racing games that supported such features?

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On 3/29/2019 at 9:01 AM, Wrathchild said:

To add to Irgendwer's points, the difference between the BBC and the C64 is that the C64 includes the colour-map support and hence it can 'paint' a large area of character cells very efficiently whereas the BBC would have to write to the screen memory (and so has only the 4 colours available). However, I would imagine that is balanced due to the BBC Master making use of the additional instructions it's processor offers as they would also give a speed improvement.

 

Weren't the 6502s in the BBC Micros 2MHz to 4Mhz?

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1 hour ago, Lynxpro said:

Oh you guys and all of this talk of increasing the fps when some of us just want a 5200 conversion and the use of a modded CX52 as a Paddle Controller for steering. Granted, we need a decent 128K RAM upgrade which nobody has done yet [to my knowledge]. 

 

I'm guessing the "easiest" way to get the fps up in A8 land would be to use the VBXE. Or the various 65816 upgrades. Or both. Of course, some would consider that "cheating". 

 

Didn't the Atari ST and Amiga versions of this game support null modem cable networking for head-to-head challenges? Or am I thinking of one of the 3 or 4 other racing games that supported such features?

The ST version certainly did.

 

I used to lug the bloody ST from my folks place to my mates (a good 5 min+ walk) plus spare TV from downstairs at his, up to his second floor landing for link up fun on this, huge laugh, but it used to upset his folks big time :-)) 

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On 12/27/2019 at 8:54 AM, Lost Dragon said:

The ST version certainly did.

 

I used to lug the bloody ST from my folks place to my mates (a good 5 min+ walk) plus spare TV from downstairs at his, up to his second floor landing for link up fun on this, huge laugh, but it used to upset his folks big time :-)) 

 

I know the feeling. I brought my 1040STf to one of the user group meetings so we could dogfight with Falcon for a group demo.

 

There should be a list somewhere of games you could connect with null modem cables, whether restricted to a single platform or multi-platform like Falcon, Stunt Car Racer, and Lotus 2. I guess it might be too much to expect the 8-bit versions to have supported any of that outside of A8/XEGS MIDI Maze. [via SIO-to-MIDI or SX212, as opposed to null modem cable].

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Off top of my head (and as I mentioned in another thread,  I have been drinking this evening,so a bit fuzzy) i remember Super Cars 2, loved that game.

 

Falcon linked up, but we got bored quickly with that.

 

 

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