[sebhc] H17 ROM and disk info

Steven Parker sp11 at hotmail.com
Sat May 22 00:58:05 CDT 2004


>Wow - you are just a wealth of information - have you ever thought about 
>writing
>some of this down?

I just did!  :-)

>#1 - Just to make sure I understand this.
>      The first "short" label sector is just after the index hole, ie: the 
>first
>      sector on a track - so in effect, there are 11 sectors/track, ...

No, just 10.  By "hole detect" I meant one of the sector holes.  The extra 
index hole does NOT constitute the beginning of a sector.  The label sector 
is the last one on the outside track .. and the same size as all the others.

>#3 - Are the sectors numbred from 1 or 0? And does this include ths short 
>sector?

>From 0 (to 9), there's no "short sector".

>#4 - If I understood the documents correctly, the sectors on track-0 always 
>report
>      volume=0 (so they can be read before mounting) - right?

Yes!  Good catch ... I forgot to mention that.

>          Check = Check XOR Data
>          Check = Check RRC (Rotate Left) 1
>        = Right?
>        = Is check performed on ALL bytes from 1st after SYNC to end of 
>data?

Yes, and yes.  "ALL" bytes are just 3 for the header and the 256 data bytes 
for the data section.

>(037,150) - all this does in INR M / RET - Can you put a name to this one?

R.ERRT   "Error test loop"

>Also, can you give me the calling conventions for the SYDD routine?

Function code in A (see dddef.acm), other registers as needed for function 
being called.

Looks like Jack scanned in the listing to answer your RAM vector questions 
(but I'm not sure why you'd need that just to emulate the device I/O).

Cheers,

- Steven

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