C64 Standard Bitmap Mode (320 x 200)

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PeterJ
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C64 Standard Bitmap Mode (320 x 200)

Post by PeterJ »

Earlier in the summer when I had more time on my hands I set myself a little challenge of trying games, and looking at the BASIC on as many 8bit platforms as possible. It's all possible through the joys of emulation!

One of the machines I looked at was the C64.

One of the modes is 320 x 200 (Standard Bitmap Mode) which I believe has the same restrictions as the Spectrum with one foreground and one background colour per 8x8 character from the 16 possible colours.

Questions:

Was this mode used for many games and was it popular?
Did the C64 suffer from Colour Clash?

In terms of BASIC the C64 is truly awful IMHO. Its as though its in alpha stage. Having to poke to get user defined graphics in character mode, or use any other other modes is a real turn off for me. Also, those PETSCII characters.... Trying to read them in magazine listings is just impossible....
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bob_fossil
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Re: C64 Standard Bitmap Mode (320 x 200)

Post by bob_fossil »

I can't answer your questions Peter but I agree with your comments about C64 BASIC. Many moons ago, I used to get INPUT magazine and would have a peek at the listings for the other machines to see what was what. The listings for C64 programs seemed to mostly consist of printing random sequences of playing card symbols and combinations of POKE and SYS statements to bang the video and sound hardware directly.
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AndyC
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Re: C64 Standard Bitmap Mode (320 x 200)

Post by AndyC »

Not much uses the bitmap modes, because it's a lot more memory and most games are tile based so better suit the character modes (where you can mix and match on a character by character basis whether they are hires or multicolour).

It has "colour clash" in the sense that if you tried to draw sprites using characters they have colour limitations, but that doesn't really happen because the hardware sprite colours are a separate thing and they don't change based on the background colours. And it's possible to multiplex them to get more on screen than officially allowed (albeit with some restrictions).

As to BASIC, yeah it is crap. The story I heard is that Microsoft wanted to charge a per-machine fee for customized versions of its BASIC implementation. Commodore balked at that and eventually agreed a flat fee to put it on as many machines as they liked, but only in a standard uncustomised arrangement. Hence the complete lack of support in the commands for any of the C64 features.
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Pegaz
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Re: C64 Standard Bitmap Mode (320 x 200)

Post by Pegaz »

Yes that C64 hi-res mode is more or less similar to Spectrum.
However, since it has hardware sprites (which can also be hi-res), with a color palette independent of the background screen, color clash is very easy to avoid.
Back in the day, hi-res titles existed, but multicolor mode was very dominant.
Hi-res is mainly used for Spectrum conversions, but there are also exclusive c64 games.
The good news for c64 fans is, that in the last few years we have had a real renaissance of hi-res games.
I already mentioned that all the Ultimate "filmation" titles have been ported and that they look really impressive.
btw, on the local Serbian forum we have a special topic, with a very detailed list of almost all c64 games in hi-res mode, so you can take a look:
https://forum.benchmark.rs/showthread.p ... gre-na-C64
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PeterJ
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Re: C64 Standard Bitmap Mode (320 x 200)

Post by PeterJ »

Thanks @AndyC,

Microsoft haven't changed much have they! MSX must have either paid up or had a much better negotiator.

Can you just expand on the character mode for me? So you can mix the 8x8 standard character and the multicolour character double width mode on the same screen?

Also, if they used character mode, how did they got pixel scrolling?
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AndyC
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Re: C64 Standard Bitmap Mode (320 x 200)

Post by AndyC »

Well Microsoft were behind the MSX standard, so they had a certain desire for those machines to come off better.

Yes, in the character mode it's possible to designate any character on screen as multicolour mode (by setting one of the colour bits or something, I forget the details). The pixel scrolling moves in high res pixels, so if you have a low res character it basically scrolls by half a "fat" pixel each time.
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Ersh
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Re: C64 Standard Bitmap Mode (320 x 200)

Post by Ersh »

PeterJ wrote:
Tue Aug 04, 2020 6:29 pm
Can you just expand on the character mode for me? So you can mix the 8x8 standard character and the multicolour character double width mode on the same screen?

Also, if they used character mode, how did they got pixel scrolling?
Multi-colour character mode allows both hi-res and multi-colour chars to be displayed at the same time. The limitation is that the hi-res chars (and individual colour of a mc char) can only use the first 8 colours of the palette.

Scrolling is handled by hardware, you can shift the screen 8 pixels in both X and Y. Coarse scrolling has to be done manually.
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akeley
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Re: C64 Standard Bitmap Mode (320 x 200)

Post by akeley »

Here's what bothers me since forever; why do C64 (and Atari) games look so blocky compared to ZX? Is their gfx resolution actually lower (is it 256x192 of ZX vs 160x200 of C64?).
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Ersh
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Re: C64 Standard Bitmap Mode (320 x 200)

Post by Ersh »

akeley wrote:
Tue Aug 04, 2020 6:55 pm
Here's what bothers me since forever; why do C64 (and Atari) games look so blocky compared to ZX? Is their gfx resolution actually lower (is it 256x192 of ZX vs 160x200 of C64?).
The c64 has higher resolution than the Spectrum in the standard hi-res modes. Most folks prefered the additional colours (at the cost of horizontal resolution) that the MC modes brought though. Also, regardless if the background and sprites are MC, their positional resolution is still 320x200.
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Pegaz
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Re: C64 Standard Bitmap Mode (320 x 200)

Post by Pegaz »

Yes, in multicolor mode horizontal resolution on C64 is 160 pixels.
In hi-res mode its 320x200 and then it is less blocky than Spectrum resolution.
I'm not too familiar with a bunch of Atari graphics modes, but I know they can be much more blocky than on the C64.
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