IDE knowledge anyone?

[Oliver Lehmann]

Chuck Guzis <cclist at sydex.com> wrote:

> On 12/10/2015 12:18 AM, Oliver Lehmann wrote:
>
>> for LBA:
>>
>> while ( pata_bsy() ) {}
>>
>> write_io_register ( PATA_RW_SECTOR_COUNT_REGISTER, 1 );
>> write_io_register ( PATA_RW_SECTOR_NUMBER_REGISTER, 0 );
>> write_io_register ( PATA_RW_CYLINDER_LOW_REGISTER, 0 );
>> write_io_register ( PATA_RW_CYLINDER_HIGH_REGISTER, 0 );
>> write_io_register ( PATA_RW_DEVICE_HEAD_REGISTER, 0xa0 );
>>
>> write_io_register ( PATA_W_COMMAND_REGISTER, 0x21 );
>>
>> while ( pata_bsy() ) {} if
>  ( pata_err() ) { return; } while (
>> !pata_drq() ) {}
>
> If you're using LBA, should this be the setting:
>
>  write_io_register ( PATA_RW_DEVICE_HEAD_REGISTER, 0xe0 );
>
> Bit 6 indicates LBA.

right - This is what I do in the code - I was writing "from memory".

> Also, note that if you're using drives larger than about 120GB, the  
> PATA-6 protocol comes into effect with 48-bit sector addresses.

OK - good to know. I only tested ranges 260MB - 80GB. Guess I'll just
not support it then?! How is it different regarding setting the
registers? But anyway... The host computer only supports 32bit
adressing of 512Byte Blocks. And I guess I could also use 500GB
IDE disks when using only lets say some hundrets of MB (plenty
enough - the original harddisk in the system had about 54MB)

Oliver