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Date   : Fri, 25 Nov 1988 07:43:00 GMT
From   : mcvax!unido!nixpbe!ugun21!josef@uunet.uu.net
Subject: Recovering Erased CP/M Files

In his note, PKNIGHT@pucc.UUCP writes:

> Is there any way to recover erased files on a CP/M disk?  These are
> WordStar files on a diskette formatted in a Kaypro machine.

Ya bet there is!

If You look at the CP/M disk directory entry format:

uu   ff ii ll ee nn aa mm ee ee xx tt   ee 00 00 nn
||   |                             |   ||       ||
||   ^-- filename.ext --------------^   ||       ^^-- file size in sectors
||                                     ^^-- extent
^^-- user area number or
  -- 0e5h if erased

aa aa aa aa  aa aa aa aa  aa aa aa aa  aa aa aa aa
|                                               |
^-- allocation group numbers --------------------^

Note: The only difference between an unused and a used entry is the
user area field value.
If the file is erased, it is e5, if not, it is 0 <= uu <= 15 (or so).
(Of course, You must somehow take the free blocks into account)

There are a number of (PD) programs floating around that do the desired
unerasing.
BEWARE: You must not do anything after having ERAsed the files.

I have one, if You want to, I'll send it to You.
Send me Your e-mail address!

               Josef Moellers

       paper mail:                     e-mail:
c/o Nixdorf Computer AG                USA:  uunet!linus!nixbur!nixpbe!mollers.pad
Abt. EG-3                      !USA: mcvax!unido!nixpbe!mollers.pad
Unterer Frankfurter Weg
D-4790 Paderborn
tel.: (+49) 5251 104691

Standard disclaimer: Blablabla opinion blablabla employer blablabla!


Date: Monday, 28 November 1988  16:01-MST
From: oliveb!intelca!mipos3!cadavr!dbraun@ames.arc.nasa.gov (Doug Braun ~)
Subject: UZI, Z80 U**x Implementation uploaded to SIMTEL20

This and the next four postings contain a shell archive of UZI, the
Z-80 U**x Implementation.  Do the usual concatenation stuff.  I have
no idea what happed to the copy I mailed to comp.sources.misc.  I was
going to upload this to the Royal Oak RCP/M, but it was apparently
down last weekend.  I will also soon post the UZI Utilities, which are
a collection of programs that will let you debug your device drivers
and build and manage UZI filesystems under CP/M.

Doug Braun                             Intel Corp CAD
                                       408 765-4279

 / decwrl \
 | hplabs |
-| oliveb |- !intelca!mipos3!cadev4!dbraun
 | amd    |
 \ qantel /

[Rather than post this large package to the Info-Cpm mailing list,
which would overload most reader's directory space allocations, UZI
has been archived and placed in:

Filename                       Type     Bytes   CRC

Directory PD2:<CPM.UZI>
UZI.ARK.1                      BINARY   60083  B603H

and is available via standard anonymous FTP or via the BITNET file
server.

RCP/M Royal Oak is down with a hard disk crash.  When it is repaired
UZI.ARK will be available there.  Telenet has blocked out our exchange
from the Detroit PC Pursuit dialout.  You'll have to dial long
distance to get to it.

UZI.ARK is also available from the National CP/M RoundTable on GEnie.

--Keith Petersen <Info-Cpm-Request@WSMR-SIMTEL20.ARMY.MIL>
]


End of INFO-CPM Digest
******************************
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