Info? ADAM Low Level Access to the DDP or Disk

[Captain Cozmos]

I am curious because for a side project I have skimmed through the ADAM technical manual and all the source code my mind can handle.
 

I see how ADAM works with the FCB in order to seek and present data but I have not seen anything which gets to the lowest level access to the drives themselves.

I understand that the Drives have BIOS's but does ADAM talk to the BIOS's and through that they grab whatever and that is about as far as one can go?

 

My whole thought process is what if you put an extremely low quality sound file on a DDP if anyone has even tried.
So someone could direct the datapack to play the data as audio.

 

I know, it sounds childish but it was a thought.

 

 

If I had to make an educated guess, before you provide me with an actual answer, is that ADAM sends a request to the BIOS, the BIOS fetches what was requested and does all this back and forth through the File Control Block.

 

 

I seriously want to know the limits of the ADAM and even now they have the thing connecting to the internet for heavens sake.

Edited July 8, 2022 by Captain Cozmos

[jblenkle]

If I am understanding you correctly about putting a low quality sound file on a DDP...ADAM simply won't read it. Certainly not an audio tape of music and if an actual DDP copy is of low quality like what you might produce trying to copy a DDP in a cheap tape deck, if the levels aren't high enough ADAM will get confused and just run the tape back and forth trying to find something it can read. I don't have the technology skills to describe it better than that, but basically that's it.

[Captain Cozmos]

What I was getting at is with low level access you should be able to tell the DDP to go to the spot on the tape and have that raw audio play through your speakers.

But that's cool, I just wanted to know if it could be done.

Edited July 8, 2022 by Captain Cozmos

[+Vorticon]

On most vintage computers wich used standard tape decks for data reading and storage, you generally could control the deck motor via a program, so if you had a piece of music on the tape and the play button was engaged, you could get it to play by starting and stopping the deck motors as needed from the program itself, perhaps to play some background tune while a splash screen is displayed. But it would have been linear as there would be no practical way to rewind or fast forward without fiddling with the deck's buttons directly.

On the Adam, the DDP is not connected to the sound output, and while the data recorded is analog, the associated read circuitry will convert it to digital (i.e 0 or 1) based on the signal threshold. If you put music on a DDP, you will be able to read the signal, but it will be extremely distorted because only a small fraction of the waveform will be read (peaks=1, valleys=0) with the rest of the waveform lost. Once that data is read, you could manipulate it to output to the speaker via sound statements.

Mind you this is all theoretical as I am not aware if anyone has ever tried this before. 

If you want to have an idea about what such "music" would sound like, just play a data tape from any computer on a regular tape deck: it will be just beeps and squeaks