What must I do to get 54 characters per line with TV_Text_Half_Height from Obex?

Christof Eb.

Hi,
in the file it is stated, that 54chars per line would be possible in pal mode.
I use the pin configuration of the demo board and I have 5MHz*16.

Thanks alot for some directions!
Christof

Coley

Hi Christof,

Have you changed the _xinfreq in the top object?

Baggers has used a 6MHz crystal so that will need changing for demoboard compatability.

To get 54 characters on Demoboard change

text.start(24,0,0,40,15)

to

text.start(12,0,0,54,15)

and in TV_Text_Half_Height object change hx settting in tv_params DAT block to 6

tv_params               long    0               'status
                        long    1               'enable
                        long    0               'pins
                        long    %10010          'mode
                        long    0               'screen
                        long    0               'colors
                        long    40              'hc
                        long    30              'vc
                        long    6               'hx
                        long    1               'vx
                        long    0               'ho
                        long    0               'vo
                        long    0               'broadcast
                        long    0               'auralcog

I hope that helps....


Regards,

Coley

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Christof Eb.

Thank you, Coley.
I have tried this - actually I had tried these things before, but there must be an additional trick. I can display 40*30 using

text.start(12,1,1,40,30)

I would suppose, that some kind of bitout frequency has to be changed, because there are more pixels to be shifted out.
I still have:
fntsc = 3_579_545 'NTSC color frequency
lntsc = 3640 'NTSC color cycles per line * 16
sntsc = 624 'NTSC color cycles per sync * 16

fpal = 4_433_618 'PAL color frequency
lpal = 4540 'PAL color cycles per line * 16
spal = 848 'PAL color cycles per sync * 16

paramcount = 14
colortable = $180 'start of colortable inside cog

despite of 5MHz, I wonder if this is correct for 54Chars.

Christof

Post Edited (Christof Eb.) : 4/17/2010 6:45:12 AM GMT

Baggers

Christof Eb. I unfortunately don't have any demo or proto boards, as I gave them away at the Maker Faire, so I can't test it at 5Mhz.

You shouldn't need to do more than the HX value, and the values in the text.start

I tried to make it as easy to set up as possible.

I'll try and get hold of another demo/proto board and get it working with 54 Chars, although 864 pixels is a LOT of pixels to get on the screen in NTSC and with a 5Mhz crystal, especially considering it's mixing two scanlines of pixels together.

Cheers,
Baggers.

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