13 Apr
2012
13 Apr
'12
1:48 p.m.
Jules Richardson wrote:
Is there any kind of sensible maximum limit for the
number of
directory entries that a CP/M disk may contain?
As far as I can tell, the upper bound appears to be 65535, which back in
the day would only have been sensible on a hard disk, and probably not
even then. Unfortunately CP/M 2.x determines the number of directory
entries is determined by the DPB (Disk Parameter Block) in the BIOS, and
not by any on-disk metadata. It is possible that some BIOSes that
support multiple media formats on the same drive might dynamically
update the DPB based on on-disk metadata stored somewhere in the
reserved tracks, but AFAIK there wasn't any standard for that.
I haven't looked at CP/M 3, so I don't know whether they improved this.
Eric