Does the X16 have raw SD card access?

[Atirut_W]

By raw access, I mean reading and writing sectors directly. Might be useful for some custom stuff

[ZeroByte]

Yes.

https://github.com/commanderx16/x16-docs/blob/master/VERA Programmer's Reference.md

$9F3E: SPI Data

$9F3F: SPI Control

 

[TomXP411]

On 7/15/2022 at 10:20 AM, ZeroByte said:

Yes.

https://github.com/commanderx16/x16-docs/blob/master/VERA Programmer's Reference.md



$9F3E: SPI Data

$9F3F: SPI Control

That's a little too raw... ideally, the CBM-DOS U1 and U2 commands should be implemented, as is demonstrated here:

https://wpguru.co.uk/2016/01/how-to-use-direct-block-access-commands-in-commodore-dos/

On 7/15/2022 at 8:15 AM, Atirut_W said:

By raw access, I mean reading and writing sectors directly. Might be useful for some custom stuff

The available commands are listed in the DOS manual, which is not part of the emulator release. You need to dig it out of the README for the ROMs, here:

https://github.com/commanderx16/x16-rom/tree/master/dos

According to the manual, the answer is "Not Yet".

[ZeroByte]

"reading and writing the sectors directly" sounds pretty raw to me.....

[TomXP411]

On 7/15/2022 at 11:32 AM, ZeroByte said:

"reading and writing the sectors directly" sounds pretty raw to me.....

There's a difference between issuing the U1 command, which takes care of the hardware access, and having to manipulate the SD card using raw SPI commands. 

Using the SPI port is akin to having to directly operate the stepper motor and read the raw GCR data on the floppy diskette... there's a whole layer of APIs in between that and Read Sector. That's actually implemented in CMDR-DOS (it has to be) but there are no public APIs for it, yet. 

 

[BruceMcF]

So the explicit answer to the question is, yes, the X16 has raw SD card access, however there is not yet a documented API for a program making use of that raw SD card access at the level of reading and writing sectors directly.