[sebhc] H17 ROM and disk info

[Dave Dunfield]

Hi Steven,

Thanks again for much useful information.

>>#1 - Just to make sure I understand this.
>>      The first "short" label sector is just after the index hole, ie: the 
>>first ector 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.

Ok - so there is a "header" with every sector. So I will essentially read two
physical blocks for every hole (not counting the index hole) - one short
"header", and one long "data" block, each with their own SYNC and CHECK bytes.

Question: Does any H8 software ever do anything "funny" with these values?
(Copy protection etc.) - would it be worthwhile to include the header in the
disk data file, or do you think it would be OK to just swallow it on writes
and regenerate it on reads.


>>(037,150) - all this does in INR M / RET - Can you put a name to this one?
>
>R.ERRT   "Error test loop"

thanks.


>>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).

Because I have no specs for the interface, so I have to figure it out by what
the software is doing. That will be much easier if I can have an idea what the
values the codes is loading/storing contain.

Regards,
Dave

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dave04a (at)    Dave Dunfield
dunfield (dot)  Firmware development services & tools: www.dunfield.com
com             Vintage computing equipment collector.
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