Sunday brain tickler

[allison]

On 01/09/2017 12:51 PM, Chuck Guzis wrote:
> On 01/09/2017 09:28 AM, Fred Cisin wrote:
>> Need there BE a filename?
>>
>> An OS, particularly for a word processor, could have an IMPLICIT list
>> of filenames on a disk of DOCUMENT1 DOCUMENT2 DOCUMENT3
>
> I found this document:
>
> http://www.dtic.mil/get-tr-doc/pdf?Location=U2&doc=GetTRDoc.pdf&AD=ADA199551
>
> about transferring Lanier "No Problem" files to a Unix (Gould 9050)
> mini.  The interchange program was a serial-comms program, so no value
> to disk interpretation.
>
> However, in section 2.2, there's light shed on how the Lanier manages
> its files.  Very unusual, but might well explain some of the directory bits.
>
> But apparently files were named--and some sort of name compression
> appears to be in use as the name of the comms program is 9 characters
> long, while the file name area appears to be only 8 bytes in length.
Low majik there...   8 bytes of 7 bit ascii means one free bytes worth
of bits,
to do that start with an 8byte area as 64 bits and stuff the bits.   The
only
question is are the left justified or right a few minutes by hand can
discover
that. Done that way 9 characters fit in 8 bytes.

Another allocation scheme is one page per track, about 1200-1500 bytes,
or about 35 pages for a 35track floppy.   So each tack is a page and the
file
header has the page name and a linked list to the next.

There are more ways to organize a disk than Carter has liver pills.

Allison

>
> --Chuck
>