A8 Bitmap Modes and cycles

[José Pereira]

Hi, just want to know how cycles are in 160resol. Bitmap Screen arranjed on the 240 Lines:

-> 1pixel high

and

-> 2pixels high (like Zybex, Draconus,...)

 

in 32, 40 and 48wide Modes?

 

(just Screen without DLIs, nor any other thing)

 

 

Thanks.

José Pereira.

[Rybags]

The PDF with the Altirra package should have all that info, it's a good reference.

 

For the 160 modes -

 

9 Refresh cycles lost every scanline.

1 DList cycle every scanline (or 2 for Gr. 7 mode), or 3 if it's an LMS instruction. Gr. 15 screens will have at least 2 LMS instructions

1 DMA cycle lost for each byte, so 40 per scanline in higher res.

 

In the lores (Gr. 7) multicolour, each second scanline has only the Refresh cycles to worry about.

[flashjazzcat]

The PDF with the Altirra package should have all that info, it's a good reference.

Thanks for pointing that out Rybags: I'd missed it before.

[+Stephen]

The PDF with the Altirra package should have all that info, it's a good reference.

I'll second that! It's a great source of information.

[José Pereira]

The PDF with the Altirra package should have all that info, it's a good reference.

 

For the 160 modes -

 

9 Refresh cycles lost every scanline.

1 DList cycle every scanline (or 2 for Gr. 7 mode), or 3 if it's an LMS instruction. Gr. 15 screens will have at least 2 LMS instructions

1 DMA cycle lost for each byte, so 40 per scanline in higher res.

 

In the lores (Gr. 7) multicolour, each second scanline has only the Refresh cycles to worry about.

 

 

Sorry returning to this one, but this I couldn't undertsand there:

 

FIRST: How many free cycles to use in an all Screen hhigh 48x15CharLines ANTIC5 Screen?

 

SECOND: How many cycles in a 48Widex15CharLines cost in ANTIC5?

 

 

 

 

Each Line it's 2pixels high, soo what I have?

 

CHARLINE=16scanlines

Each A8Line=2Scanlines.

 

1st Scanline: 1_refresh+1_CharsetDLI+48_Charset+48_Chars

2nd " : 9_refresh cycles+1_CharsetDLI

3rd " : 9_refresh+48_Chars

4th " : 9_refresh

5,7,9,11,13and15 like 3th scanline

6,8,10,12,14and16 like 4th.com scanline.

 

????

 

Thanks.

José Pereira.

Edited November 16, 2010 by José Pereira

[Rybags]

48 byte modes are variable depending on what HSCROL value is in use - can be less if HSCROL is a higher value.

 

The Altirra docs has good info there.