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Coding > probable error in the nocash specifications

#25697 - nmcconnell - Fri Aug 27, 2004 7:01 am

I think I found an error in the nocash specifications document at
http://www.work.de/nocash/gbatek.htm

I'm posting it here because I couldn't figure out how to get in touch with however's maintaining the document.

I should mention that it's 2AM, so I appologize if this is just my own foolishness.

Anyway, the doc repeatedly mislabels VRAM, including
>>0600:0000-0617:FFFF VRAM - Video RAM (96 KBytes)

and

>>VRAM - Character Data
>>OBJs are always combined of one or more 8x8 pixel Tiles (much
>>like BG Tiles in BG Modes 0-2). However, OBJ Tiles are stored in a
>> separate area in VRAM: 06100000-0617FFFF (32 KBytes) in BG
>>Mode 0-2, or 06140000-0617FFFF (16 KBytes) in BG Mode 3-5.
>>Depending on the size of the above area (16K or 32K), and on the
>> OBJ color depth (4bit or 8bit), 256-1024 8x8 dots OBJ Tiles can be
>>defined.

I'm bringing this up because the bit on character data, combined with either a corrupted or insanely obsolete gba.h (by eloist) caused me some major headaches trying to get a sprite to show (it's my first attempt at doing this).

Anyway, I totally love the nocash specifications. I think they're an awesome resource, and they're where I'm most likely to go looking for info when I'm coding. that's why I'd like to get this updated for anyone else who's trying to get started.

thanks
--neil

#25699 - wintermute - Fri Aug 27, 2004 9:04 am

What is it that you think is wrong?

#25700 - FluBBa - Fri Aug 27, 2004 9:59 am

It should be 06000000-06017FFF, not 0617FFFF.
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#25709 - nmcconnell - Fri Aug 27, 2004 3:23 pm

FluBBa is correct. This became an issue because writing my Object Tiles to 0x061000000 failed to produce the anticipated results. (should have been 0x060100000)

#25712 - MumblyJoe - Fri Aug 27, 2004 4:48 pm

nmcconnell wrote:
FluBBa is correct. This became an issue because writing my Object Tiles to 0x061000000 failed to produce the anticipated results. (should have been 0x060100000)


True. It's very easy to see where you have gone wrong with memory locations on the gba because everything is on a nice even boundary.

However I think you mean 0x06010000 :P
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