E format discs

Don't need compacting
Don't get map full errors
Floppies can now also do defect skipping (was only winnies with old map) as *format will map out any defects it finds
Defects can mapped out without reformatting (both floppies and winnies) using the command *defect <disc spec.> <disc add.>

New configuration commands

*configure ADFSDirCache <size> [K]: This reserves some space for ADFS to keep a cache of recently used directories in a compressed form.
*configure ADFSbuffers <buffers>: This is used to reserve a number of 1K buffers which ADFS can use to speed up BGET, BPUT and GBPB. They are used for write behind, read ahead and caching of most recently used file buffers. If underused some of this space can get temporarily transferred to the directory cache. It does not have an optional K in the syntax since each buffer has a small overhead and hence the space reserved is not an exact number of Kbytes.

*Verify

*Verify will now do up to 5 retries, and report where it retried. Typical output

 Verifying ...
 0009A800 ?? Managed to verify sector after 2 retries
 Disc error 08 at :0.000C5400 Failed to verify sector after 5 retries
 Verify failed

Final message is one of

 Verified ok

 Verified with retries

 Verify failed

Some discussion of soft and hard errors needed. This ties in with defects.

RAMFS

The module RAMFS provides a filing system RAM: which appears to the user much the same as ADFS.

New adfs SWIs

ADFS_Retries &40244

This can be used to read/write the retry word, the 4 bytes of which have the following meaning.

byte meaning
0 number of retries for hard disc read/write sector
1 number of retries for floppy disc read/write sector
2 number of retries in floppy disc mount for each copy of map
3 number of retries for verify after *format before called a defect

On Entry:

R0 bits to change
R1 new bits

On Exit

R0 preserved
R1 masked by R0 = R1 AND R0
R2 old value of retry word
R3 new value of retry word = (old value BIC R0) EOR (R1 AND R0)

ADFS_DescribeDisc &40245

On Entry:

R0 -> disc specifier string
R1 -> 64 byte block to fill in as disc record

On Exit: The disc record is filled in as follows:

0 - log to base 2 of sector size
1 - sectors per track
2 - heads (1 for L format disc)
3 - density 1/2/4
4 - width of id field in bits
5 - log to base 2 of bytes for each map bit or 0 for old map
6 - track to track skew for random access files
7 - boot option
8 - reserved
* 9 - number of zones in the map
10-11 - non map bits in zone
12-15 - system internal number of root directory
16-19 - disc size in bytes
20-21 - 2 byte disc id
22-31 - disc name
32-63 - reserved

Entries marked * refer to details of new map format

Attribute extension

New directory discs (ie all except L format) have extended attributes. Bits 4-7 no longer repeat bits 0-3, but the only use ADFS makes of them is to display bits 4 and 5 in *FileInfo

 bit meaning
 0 owner read access
 1 owner write access
 2 always zero
 3 locked bit
 4 public read access
 5 public write access
 6 reserved
 7 reserved

Extension of up call protocol

UpCall_MediaNotPresent (1) and UpCall_MediaNotKnown (2) have had their parameters extended as below to allow the Wimp to detect insertion of a disc if a drive supports disc changed.

R1 - filing system number
R2 -> media name string or -1 if irrelevant
R3 - device number or -1 if irrelevant
R4 - iteration count 0,1,2,.. for repeated issuing of call
R5 - minimum polling period in centiseconds for claiming upcall, -1 if not to poll
R6 -> media string eg. 'disc'