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Apple II Csa2 FAQs: File Utilities, Part 10/25

( Part1 - Part2 - Part3 - Part4 - Part5 - Part6 - Part7 - Part8 - Part9 - Part10 - Part11 - Part12 - Part13 - Part14 - Part15 - Part16 - Part17 - Part18 - Part19 - Part20 - Part21 - Part22 - Part23 - Part24 - Part25 )
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Archive-name: apple2/faq/part10
Posting-Frequency: monthly
Last-modified: 2009/12/01

See reader questions & answers on this topic! - Help others by sharing your knowledge
The comp.sys.apple2 Usenet newsgroup Apple II FAQs originate from
the II Computing Apple II site, 1997-2010. 

Csa2 FAQs file ref: Csa2FLUTILS.txt  rev141 December 2009

File Utilities

 001- What are "binscii" files and how are they used?
 002- What are .SHK files and how do I use them?
 003- How do I get ShrinkIt or GS-ShrinkIt going on my Apple II?
 004- How do I deal with the $00 type Apple II files I get on my Mac?
 005- Can I work with .zip files on my Apple II?
 006- What are DSK, NIB, 2MG, HDV,... disk image files & how do I use them?
 007- Where can I get ShrinkIt, binscii, DSK2FILE, ASIMOV, etc.?
 008- I have downloaded  files in "gz" format? How do I use them?
 009- Which programs can change ProDOS filetype?
 010- What is Copy II Plus and where can I get it?
 011- How do I use Copy II Plus to create and convert IMG files?
 012- How do I set write protection for an emulator disk image?
 013- How can I create a disk image from a ShrinkIt .sdk file?
 014- How can I convert a .po image to/from a .dsk or .do image? 
 015- What do file name extensions mean and how do I access the files?
 016- How do I tell what kind of file this is?
 017- How can I create new .dsk, .nib, etc. disk images?
 018- How can I convert .dsk image <--> .nib image?
 019- How can I convert Diskcopy images to diskette or to other formats?
 020- How can I move files to/from .dsk and .2MG disk images?
 021- How can I unfork forked files on my Apple II?
 022- How can I mount disk image files directly under GS System?

From: Rubywand

001- What are "binscii" files and how are they used?

     The term "binscii" comes from combining "binary" with "ASCII".  A file in binscii form has been changed so that it can be transmitted as text to/from net servers and services which do not handle pure binary transfers.

     Today, practically all servers can handle pure binary transfers; so, binscii is no longer in popular use. However, quite a few old A2 files are still in binscii form and binscii is used for files uploaded to comp.binaries.apple2.

     To convert binscii'd files to their un-biniscii'd form, you can use a program named "BINSCII" or, on a GS, the New Desk Accessory named "GScii". These programs can, also, create binscii files.

Note: Binscii is in no way related to Binary II. Binscii changes the entire file into Text. Binary II is just a small block of bytes tacked onto the front of a file, mainly to identify the file's filetype.


002- What are ShrinkIt (.SHK) files and how do I use them?

    ShrinkIt files are the Apple II world's answer to .ZIP files in PC-ville. An .SHK file is a file which contains one or more files which are almost always in compressed form. Usually, they are produced by GS-ShrinkIt (also called "GSHK" or "ShrinkIt-GS") or the Balloon NDA, or by 8-bit ShrinkIt. Some .SHK files are produced by Macs; these may not always be compatible with A2 ShrinkIt programs.

     An .SHK file can be unshrinked by ShrinkIt even if it shows up on the Apple II with a TXT or BIN filetype and even if the name does not end with ".SHK" or ".shk". If a ShrinkIt file does not show up as available for unshrinking, you can toggle an "All files" option to see the file and then select it. If an .SHK file has a Binary II header, ShrinkIt will automatically remove it and assign the correct filetype. (Of course, this will usually be SHK.)

     Other kinds of ShrinkIt files include .SEA and .SDK.  An Apple II .SEA file is a IIgs executable self-extracting archive-- i.e. you can click it on the GS Finder and it will unShrink. There are also Mac .SEA files and these are not GS-compatible.

     A ShrinkIt whole-disk archive is an .SHK file which is usually labeled ".SDK" to show that it is a Shrinked diskette. An .SDK file can archive a 3.5" diskette (both sides) or 5.25" diskette (one side). Most are archives of 5.25" DOS 3.3 diskettes produced by 8-bit ShrinkIt.

     A whole-disk ShrinkIt archive retains all data bytes on a diskette, including files, Catalog/Directory sectors, empty tracks, and DOS if present. An .sdk file of a DOS 3.3 5.25" disk created by 8-bit ShrinkIt also preserves volume number-- important for some games and utilities which depend upon volume numbers to identify disks. (5.25" whole-disk archives created by GS-ShrinkIt do not preserve volume number.)

     8-bit/IIe ShrinkIt can be used to fully unshrink any Apple II .SHK file _except_ .SHK files which contain files with GS/OS resource forks and .SEA files. For this reason, 8-bit ShrinkIt should not be used to unshrink .SHK file archives containing GS programs unless you know that none of the contained files has a resource fork.

     GS-ShrinkIt can handle nearly all kinds of Apple II .SHK and .SDK files. It will not handle shrinked 5.25" DOS 3.3 .SDK files created by 8-bit ShrinkIt. In fact, most users automatically use 8-bit ShrinkIt to create and unshrink .SDK files of old 5.25" wares. (Balloon does not currently support whole-disk archives.)

     Naturally, things are somewhat more crowded on 64K Apple II's. On these machines, the functions are separated. SHRINK creates .SHK files and UNSHRINK unshrinks them.

     On a PC, the utility NuLib (v3.24) lets you view contents and unshrink most kinds of .SHK files. (There is a handy option to unshrink and convert Apple II text files to PC text format.) It will not unshrink IIgs files with resource forks.

     Here is a simple one-line batch (text) file program for easily viewing the contents of .shk files you download to a PC (just double-click on the file name):

c:\nulib\nulib v %1 |more

The above is for NuLib.exe located in folder c:\nulib . Save the text as nulibv.bat in c:\nulib and tell Windows to use c:\nulib\nulibv.bat as the 'application to perform action' for doing an Open. (You do this by selecting View--Options in the My Computer window and editing the file type info for .shk files.)

     NuLib can also convert 5.25" .SDK files into .PO (ProDOS order) disk images which can be used by Apple II emulators. This works for .SDK files produced by 8-bit ShrinkIt but not for those produced by GS-ShrinkIt.

     The unshrinking process is very speedy and the size of a compressed ShrinkIt file is, often, around half that of the original files it contains. This makes .SHK files very handy for archiving your software. And, since a ShrinkIt file also preserves filetype information of contained files, ShrinkIt has become the preferred format for uploading and storing Apple II files on the internet.


003- How do I get ShrinkIt or GS-ShrinkIt going on my Apple II?

Getting GS-ShrinkIt v1.1

     If you do not already have Balloon or an earlier version of GS-ShrinkIt, there are several ways to get GS-ShrinkIt going once a file is downloaded and transferred to your IIgs. Here are the two easiest ways:

A. The Self-Extracting (.sea) version

     A IIgs .sea file is a IIgs application which self-extracts the file contents when executed from the usual Finder desktop display. Since the file gshk.sea will, most likely, arrive as a Text type file, you will need to change the file's filetype to $B3 (S16) before it can be executed.

     Several utilities can change ProDOS filetype. If you do not have one, you can download tchange.bin and follow the directions* in tchange_info.txt  to get it going on your Apple II.

     You can find GS-ShrinkIt in an .SEA file (e.g. gshk.sea) and tchange.bin on several archive sites. (See Q&A 007 below.)

B. The Shrinked Disk (.sdk) version

     GSUTILS.sdk is a shrinked whole-disk file which can be unshrinked to 800k 3.5" diskette using 8-bit ShrinkIt (or GS-ShrinkIt).  If booted, this diskette starts a bare-bones System 6.0.1 and launches GS-ShrinkIt.

     Besides GS-ShrinkIt, also on the disk (in .SHK files) are the ZLINK shareware telecom utility and ASIMOV for converting .dsk files. Coolwriter (for reading Text) is on the disk as a non-shrinked file. All of these can be copied to hard disk or to other diskettes.

     GSUTILS.sdk is available on Ground in the useful.stuff/ folder mentioned above. The 8-bit ShrinkIt in a self-extracting version can be found in the same folder.

Getting SHRINK and UNSHRINK (for 64k Apples)

     SHRINK and UNSHRINK permit 64k Apple II users to work with .SHK files. These files are usually maintained in non-shrinked form. You can find them on several sites.  (See Q&A 007 below.)

     To get these utilities going on your Apple II, download SHRINK, UNSHRINK, and SHRINK2PLUS.TXT (e.g. as separeate files or on a .dsk disk image). Once the files are transferred to your Apple II, follow the directions* in SHRINK2PLUS.TXT.

*Note: If you download an Apple II file to a PC and transfer to a Mac and get filetype $00 ("Unknown"),  the process described in the directions will not work when the $00 file is moved to your Apple II. One solution is a Mac utility to set filetype to $04 (TXT). See ProTYPE info in the next Q&A below.


Getting 8-bit ShrinkIt

From: Beverly Cadieux

     The easiest way to get the current (3.4) version of 8-bit ShrinkIt going is via the self-extracting archive, SHRINK.EXE.

o- Download the file, (transfer to your Apple II if necessary,) and get into AppleSoft BASIC (run BASIC.SYSTEM and get to the AppleSoft "]" prompt).

o- Be sure to set the ProDOS PREFIX to the location of SHRINK.EXE on your Apple II. For example, if it is in the main directory of volume HD1, you would enter


o- Now, enter -SHRINK.EXE (that's a dash, then the file name):


     Shrinkit will self-extract, along with a documentation file. (ShrinkIt v3.4 consists of two files. One is a small start file which may be named "Shrinkit.System", "ShrinkitST.sys", or something similar. The other is the main program file which must be named "Shrinkit".)

     You can find SHRINK.EXE in Ground's useful.stuff/ folder (See Q&A 007 below).


From: Randy Shackelford

004- How do I deal with the $00 type Apple II files I get on my Mac?

     Some II users like to download Apple II files to a PC and transfer them to a Mac for eventual transfer to Apple II ProDOS diskettes. Unfortunately, under most circumstances, PC Exchange writes files onto ProDOS disks as extended typeless ($00) files which are difficult to work with on the Apple II.

     What you need is to get hold of a Mac application named "ProTYPE". You drag 'n drop the files on ProTYPE, then copy 'em to the floppy. The files will work then.


From: Rubywand

005- Can I work with .zip files on my Apple II?

     The GS can unZIP .zip files via PMPunZip by Paul Parkhurst.


From: Supertimer

     Tony Marques wrote Angel, the fastest unzipping utility for the Apple II. It can create .zip files, but only one file per archive.


From: Jim Pendarvis

     To zip a file using Angel, highlight the file to zip and press OpenApple-Z. You'll get a file named ZIPDFILE.ZIP. If you then select another file to zip, it will overwrite the first one. (Don't forget to set your destination directory first. That is the hardest thing to remember about using Angel.)


From: Rubywand, Orgone Accumulator, Greg E. Nelson, Eric Shepherd, Roger Johnstone

006- What are DSK, PO, DO, HDV, NIB, and 2MG "disk image" files
     and how do I use them?

     A "disk image" is typically a file containing every data byte on a diskette-- i.e. Catalog tracks, files, DOS (if present) etc.. One kind of disk image, NIB, tries to preserve all disk information (e.g. sector headers, sync bytes, etc.).

     Apple II emulators running on a PC, Mac, etc. treat disk image files like diskettes. Disk image files are also a handy way to archive Apple II disks on hard disk and to maintain wares on ftp and other download sites.

DSK's (.dsk, .do, .po and .hdv files)

     DSK (usually .dsk) files are disk image files used by popular Apple II emulators like AppleWin to run A2 wares on the PC or Mac. Usually, they are images of Apple 5.25" game, utility, etc. diskettes. A standard 5.25" DSK file is 143,360 bytes in length:

1 side x 35 Tracks/side x 16 Sectors/Trk x 256 Bytes/Sec = 143,360 Bytes.

DSK files of 800k 3.5" disks are much less common.

     Data in a DSK disk image file can be arranged in the sector order used by DOS 3.3 or in the sector order used by ProDOS. The filename suffixes relate chiefly to how data is arranged in the file:

.dsk- technically, this may be an image which has its data in DOS 3.3 or ProDOS order. (The emulator program is supposed to check a .dsk file to determine the ordering used.)  It has become standard practice to use the .dsk suffix for only DOS 3.3 order files.

.do- an image which is in DOS 3.3 order. This suffix is seldom used today. DOS 3.3 order image file names usually end with ".dsk".

.po- an image which is in ProDOS order. If an image is in ProDOS order, its name should end with ".po" (not ".dsk") to avoid confusion.

.hdv- typically an image 800k (819,200 bytes) or greater in size in ProDOS order. The image is intended for use as a virtual hard disk by various Apple II and IIgs emulators (e.g. Apple Oasis).  The IIgs program ASIMOV2 can create .hdv files (select "Raw image").  The file name should end with ".hdv".

Note: data order does not relate to whether a disk image is a DOS 3.3 or ProDOS disk. In fact, nearly all 5.25" disk image files (of both DOS 3.3 and ProDOS disks) are in DOS 3.3 order; and, DOS 3.3 order is the default setting for image creation programs like DSK2FILE and ASIMOV and the transfer/creation program ADT.

     On a PC, NuLib can create disk images from 8-bit ShrinkIt whole-disk (.sdk) files (but not from .sdk files which were produced by GS-ShrinkIt).  These images will be in ProDOS order. You can convert a .po disk image to a DOS 3.3 order .dsk by using a disk copier like Disk Muncher on an emulator to copy from the .po image to a .dsk image.

     On ftp sites, DSK files are usually in a ZIPped form to conserve space. For example, on the Asimov site, narfgames.dsk.gz is a DSK file of the narfgames disk which has been g-zip compressed. Other archive sites may use standard ZIP compression and the file name might be "" or "". On a PC, WinZIP will uncompress g-zipped and ZIPped DSK files.

     A DSK file can be converted to actual diskette form on an Apple II using DSK2FILE or (GS-only) ASIMOV.  If a 5.25" .dsk disk image file is transferred to your Apple II using ADT (or ADTgs for IIgs), it is automatically converted and written to 5.25" diskette. For more about ADT and ADTgs see Telecom-1.

     Most 5.25" DSK (.dsk and .do) files are of a DOS 3.3 or some related DOS disk. The target diskette should be INITed for DOS 3.3. (or, it can be formatted using Copy II Plus, etc.) and you should use the default DSK2FILE or ASIMOV "DOS 3.3 Order" setting. If a disk image file has a .po suffix, use the DSK2FILE or ASIMOV "ProDOS Order" setting.

Note: In most cases it is okay to use either a DOS 3.3 or ProDOS formatted diskette as the target (and; the target disk does not need to be empty of any files).  However, ProDOS formatting uses a default Volume Number of 1, which is different from the DOS 3.3 default of 254. Since ProDOS stuff does not care about Volume numbering and DOS 3.3 stuff may, the target disk should generally be one INITed with the default Volume Number-- e.g. INIT HELLO .

     Here is a quickie step-by-step guide for getting a 5.25" DSK disk image file into useable form:

1. Download the file in binary mode from an ftp archive site via ftp:// ...

2. If file length is not 143,360, use WinZIP or equivalent to unZip it.

3. Transfer the DSK file to your GS via Mac diskette or a NULL modem transfer. One way or another, the file needs to end up on a ProDOS diskette or ProDOS hard disk volume on the GS.

4. If you are using DSK2FILE, jot down the complete path name of the DSK file (e.g. /RAM5/NARFGAMES.DSK ) because DSK2FILE will ask you to type it in.

5. Insert the formatted  5.25" target diskette into Drive 1 (Slot 6). This diskette needs to be 16-sector formatted. Plain DOS 3.3 formatting with the default Volume number is, generally, best and easiest. (You can boot a DOS 3.3 or Prontodos disk and do an INIT HELLO to format a 5.25" diskette.)

6. Start DSK2FILE or ASIMOV. Normally, you will accept the defaults (5.25", DOS 3.3 order). If you know the DSK is a ProDOS image in ProDOS order-- like the file name ends with ".PO", select "ProDOS Order". (ProDOS disk images are, fairly often, in DOS order to make them more universally transferable.)

7. Select the "Image file ---> Diskette" option, follow prompts, and you should end up with a good diskette. (If everything seemed to go well but the disk does not work, try repeating the process using the other "Order" option.)

     DSK2FILE and ASIMOV can, also, create disk image (.dsk or .po) files. Similarly, using ADT to transfer a 5.25" disk automatically creates a .dsk disk image on the PC. The source disk can be for a game, etc. so long as the diskette is not copy protected.

Note: DOS 3.3 products which depend upon Volume numbering to identify diskettes will normally not work in disk image form on an Apple II emulator because Volume number information is embedded in non-data parts of a disk and is not included in a standard .dsk disk image file.

NIB (.nib)

     Some copy protected diskettes can be converted to another kind of disk image called "NIB". Saltine's Super Transcopy (SST) incorporates bit copy routines to attempt to produce a nibblized disk image of a 5.25" diskette.

     On your Apple II, SST reads the disk bytes from half a disk and stores that data on a whole normal disk. Then it does the same for the second half. These two disks can be converted to .dsk disk images and moved to a PC or Mac. There, the .dsk images are merged into a NIB image using SST running on an emulator.

     If successful, you have a .nib file which can be used like a diskette on popular Apple II emulators. (For one or two older emulators, .nib files are the only useable images.)

     The standard length of a .nib file is 232,960 bytes-- much larger than a DSK. However, since .nib files include sector address header and other non-data 'embedded' diskette information, they can be used to image many protected disks.

     Naturally, a .nib file preserves DOS 3.3 volume numbering. This allows programs which use volume numbers to identify their disks to run on emulators. Many disks with no copy protection are in .nib form instead of .dsk because the game, etc. which uses the disks needs to check volume numbering.

2MG (.2mg; sometimes .2img)

     Today, more and more IIgs software is being converted to 2MG disk image format used on XGS and other IIgs emulators. These are .dsk or .nib images with a prefix (usually 64 bytes) which includes information about size, format, sector ordering, volume number, locked/unlocked, etc..

     2MG files may also have a Comment and/or extra file information added following the disk image data. The format can accommodate disk images ranging from 5.25" diskette up through hard disk. For 2MG format details, see .

     The usual length of an 800k .2MG image (with no Comment or extra data) is 819,264 bytes*.

     You can use ASIMOV2 to convert .2MG files back to diskette form as well as for creating .2MG files from 800k diskettes. The utility Imgutnew.exe can be used to convert most available Diskcopy images to 2MG format on PC.

*See ...  Size Note: Transferring to 3.5" disk (at bottom of this page)


From: Rubywand

007- Where can I get ShrinkIt, Shrink (64k), Unshrink (64k),
     GS-ShrinkIt, binscii, GScii, BISCIT, TCHANGE, DSK2FILE, ASIMOV,
     PMPunZip, Angel, FileManager, 2qwk!, GZPK, Disk Muncher, Copy II Plus,
     NuLib, Balloon, DskIn & DskOut, Saltine's Super Transcopy (SST),
     FishWings, UnforkIt, XTRAX, StuffIt Expander, Diskcopy, Clone,
     Imgutnew.exe, DiskDup+, ProTYPE, MECC Copy, BlockWarden, BlockWork,
     ProDOSifier, DISK2FDI, CiderPress, ProDOS File Navigator, FID,
     Apple Commander, and MountIt?

     For links, see Csa21MAIN4: Get It- Links to popular software packages.


008- I have downloaded a bunch of files for the Apple II
     lately that are in a format called GZ.  I understand it
     is some variation of Zip but I don't have a translator for
     it on my GS. Does anyone know where I can find one?

     5.25" disk image files downloaded from Asimov, mod files, and some others are, often, in GZ g-zipped format and usually have the .gz file name extension (like narfgame.dsk.gz). If you download the files to a PC, you can use WinZIP to unzip the file.

Note: Due to the use of an extra period, names of g-zip compressed files-- names such as "narfgame.dsk.gz"-- do not always survive downloading to PC's. Some setups may remove the ".gz" from the name when saving the file. In order to be correctly recognized by WinZIP, the file's name should be repaired so that it ends with ".gz".

     Usually, once unzipped, an Asimov GZ image file will end up as a 143,360 byte DSK file with a name ending with ".dsk". The file may be used as a virtual diskette on an emulator like AppleWin; or, it may be transferred to a real Apple II via NULL modem and converted to Apple-readable diskette form using DSK2FILE or (GS-only) ASIMOV. (Or, it may be NULL modem transferred directly to 5.25" diskette via a version of ADT.)

     If you download a GZ file directly to your Apple you can use a program named "GZPK" v2 to convert it from gzip form to a zip format which can be unzipped via PMPUnzip 2.0 or Angel. A GZ file from the Asimov site should end up as a DSK file.


From: lachlan_arnott and Byron Desnoyers Winmill

     On a Mac, you can use MacGzip to unZIP g-zipped (.gz) DSK files into uncompressed form. Another choice (for doing the same job as WinZIP on a PC) is Aladdin's StuffIt Expander and the DropStuff Expander Pack.  These utilities can be found on many Macintosh related ftp sites. (See Q&A 007.)


From: Slick

009- Which programs can change ProDOS filetype?

     I prefer More Info or Disk Witch, myself. I'll go through a list of stuff on my hard drive to manipulate filetypes:

Alter (NDA)
Conchshell (CDA)
Disk Witch (CDA)
File Manager (NDA)
File Info2 (NDA)
File Info Edit (NDA)
Super Info II (NDA)
Utilities CDA (CDA), not very good

Finder Extras:
More Info

GS/OS Applications:
Instant Access
File Passage

ProDOS 8:
FAZ II (File Attribute Zap II)


From: Boris Guenter

File-A-Trix by Karl Bunker should do the job. Best of all, the latest (and last) version 1.1.1 of this program is freeware.

Since I had a few troubles with the latest version, I suggest trying both versions 1.1 and 1.1.1.


From: Tony Ward

I also prefer File-A-Trix. It performs a wide variety of functions including copy, move, delete, rename, catalog, make new folder, set file attributes (lock, unlock, filetype, auxtype), find file, format (floppy only), view text, Teach and AWP files. Best of all, it's a CDA that works from GS/OS and ProDOS 8, although there are some restrictions under P8 (i.e. no HFS disk access, no viewing forked Teach files, etc.)


From: Gareth Jones

I use either File-A-Trix, Change-A-File 4.20, or Deliverance (part of the Salvation Utilities).


From: Rubywand

     Some programs which can be used to change filetype are ...

Jeff Hartkoph's File Manager- a GS NDA which lets you change Type, Auxtype, Date, and Access attributes. It is handy for modifying several files in quick succession.

Paul Parkhurst's PMPunZip- a GS application which includes an option for changing Type, Auxtype, and Access attributes. (In the File menu click on Modify File Attributes.)

Glen Bredon's ProSel (ProDOS 8 utilities)

Roger Wagner's Filetype Changer- a vintage BASIC utility which lets you change just the Type. A BRUN-able .BIN version is on Ground. (This is good enough for getting the GS-ShrinkIt .SEA file's filetype set correctly so that it can self-extract.)


From: Beverly Cadieux

     And a biggie - AppleWorks v5.1-> File Activities, Change File Type.


From: Jay Edwards

     TimeOut FileMaster does a great job and never argues about it.  Best of all, it likes so many versions of AppleWorks.


From: Rubywand

010- What is Copy II Plus and where can I get it?

     Copy II Plus is the best general purpose utility for copying disks and managing files on DOS 3.3 and ProDOS diskettes. Most of the Copy II Plus functions also work with disk images (e.g. .dsk files) on emulators; however, COPY DISK and FORMAT are important functions which do not work correctly with emulators. Good versions which handle both DOS 3.3 and ProDOS files are 7.x - 8.x.

Note: Versions 9.x require at least an enhanced IIe and have a few notable bugs. Version 9.0's Catalog Sort option can mess up your directory. Neither version 9.0 nor 9.1 works correctly with the /RAM5 RAM disk.  The best added capability of Version 9.x is being able to compare files.

     No version of Copy II Plus will copy files which include a resource part, usually called a "resource fork". In some cases the copy may seem to be successful; but, it will be a mess. Only some, relatively new, IIgs files include a resource fork. No DOS 3.3 files or files intended for access under ProDOS 8 have resource forks.

     The most versatile releases of the utility are, probably, Versions 7.1 and 7.2. They include the capability for creating disk images. The images are not compatible with popular emulators; but, they are a handy way to archive DOS 3.3 disks on a hard disk.

     For places to get Copy II Plus in ShrinkIt shrinked disk and emulator disk image files, refer to Q&A 007 above.


From: tturner, Rubywand, Greg Buchner, Labelas Enoreth

011- How do I use Copy II Plus to create and convert IMG files?

     First, to the best of my knowledge, only versions 6.x and 7.x of Copy II Plus can create a disk image file (called an "IMG" file). The feature was gone by version 8, for sure.

     To create an IMG file you COPY--> DISK to an over-size target volume. Versions 6 and 7 will create a type "IMG" file instead of complaining about a "size mismatch" (which is what other versions of Copy II Plus do). It is fairly common to end the name of the new IMG file with ".img".

     Doing the opposite lets you convert an IMG file back to diskette. That is, you select the COPY --> DISK option and pick the large volume with the IMG file as Source and a blank unformatted 5.25" diskette in the Slot 6, Drive 1 drive as Destination. You pick an IMG file on the Source volume and it is transferred to the diskette.

     Copy II Plus IMG files are not compatible with DSK2FILE or ASIMOV and will not work on emulators such as AppleWin. Also, not all files ending with ".img" are Copy II Plus disk image files. I have seen ".img" (and ".image") used for Diskcopy disk image files.


From: Rubywand

012- I'm using an Apple II emulator to play games. The game directions
     say the boot disk must have a write protect tab. How do I set
     write protection for a disk image?

     Under Windows on a PC, you can right-click on the file name, select Properties, and adjust the "Read-only" attribute. Checking "Read-only" turns ON write protection; unchecking it turns write protection OFF.


From: Jon Bettencourt

     On a Mac, you select the file, go up to File --> Get Info..., and click on "Locked."


From: Rubywand

013- How can I create a disk image from a ShrinkIt .sdk file?

     NuLib v3.24 can be used to make .po disk images from ShrinkIt 5.25" whole-disk archives-- e.g. .sdk files.

Note: NuLib v3.24 can create 5.25" disk images only for .sdk files created by 8-bit ShrinkIt (not ones created by GS-ShrinkIt).  Since most .sdk files were created by 8-bit ShrinkIt, there is usually no problem.

     For instance, suppose you have downloaded a whole-disk archive (.sdk file) of a 5.25" disk of modem utilities named "modem1.sdk" and wish to convert it into a disk image. For this example, it is assumed that you have downloaded NuLib v3.24 and unZIPed it and, now, have all of your Nulib stuff (nulib.exe, docs, etc.) in C:\nulib on your PC:

o- After downloading to the PC, check the file name of the .sdk file you want to convert. The name should have from 1 to 8 characters followed by ".sdk". If it doesn't, rename the file so that it does. The file modem1.sdk follows the above rule; so, there is no need to rename it.

o- Move or copy modem1.sdk to the C:\nulib folder.

o- Since you are probably in Windows95 (or later) open an MS-DOS window.

o- In the DOS window, go to the nulib folder ...


C:\>cd nulib

o- Enter the xd command to create the disk image from modem1.sdk:

C:\nulib>nulib xd modem1.sdk

You should get a message saying the 'NEW DISK' image is being extracted ending with "...done".

o- Exit the MS-DOS window-- e.g. click on the "X" in the corner.

o- Open the C:\nulib folder. Probably, your new disk image will be named "new.dis". Rename the new file to "modem1.po". It should show up with a size of 140k in the usual Windows listing. (If it shows size 0, go to "View" for the window and click "Refresh".)

If the new modem1.po has some size other than 140k-- like size is shown as 75k, etc.-- it means that modem1.sdk was probably created by GS-ShrinkIt and can not be converted to a disk image using NuLib. (You might as well scrap the bad modem1.po .)

Most likely, though, the conversion will work and modem1.po will be a good disk image.


014- How can I convert a .po image to/from a .dsk or .do image? 

     Most emulator programs have no problem using .po, .do, or .dsk disk images. So, the usual reason for wishing to change ordering is to go from .po (ProDOS order) to .dsk (typically, DOS 3.3 order)  to permit transferring the image to your Apple II via ADT. In a few cases, it may be useful to go from DOS 3.3 order to ProDOS order, too.

     Since a disk copy done on an emulator (like AppleWin)  adjusts ordering to match the target, doing a disk copy from, for example, a .po image to a .dsk image (in DOS 3.3 order) is a simple way to do a conversion*. A good emulator choice for Windows users is AppleWin. A good disk copier program is Disk Muncher-- it is included on the TNILUTIL.DSK available from Ground and GSWV.

     An easy way to check ordering of a bootable .po or .do disk image is to boot it under AppleWin. If it boots correctly, the ordering is as claimed-- .do = DOS 3.3 order and .po = ProDOS order. For a bootable .dsk image, you can change the suffix to ".do" or ".po" and boot it to check that it is really in the order you expect.

*Note: AppleWin, evidently, checks the ordering of a .dsk image used as a target for copying. It does not check actual ordering of .po or .do images. So, for example, if the target image has the ".po" suffix, the copy to the image will be in ProDOS order. Some emulators may work differently.


From: David Kopper, Dan DeMaggio, Boris Guenter, Nathan Mates,
      Phil Abro, Rubywand, Labelas Enoreth, Tony Turner

015- What do the different popular file name extensions, like ".BSC",
     mean; and, how do I access the files?

     File name extensions tell you what sort of file you are dealing with so that you will know which program(s) to use to unpack, unShrink, display, etc. the file. Many programs which create such files do not automatically add an extension-- for example, most of the disk images on the Golden Orchard CD are Diskcopy files with no name extension. Many other programs which create files suggest a default extension as part of the name-- GS-ShrinkIt generally suggests ".SHK"-- but, the user can change this and 
save under any legal name desired. (One popular change is using ".SDK" for ShrinkIt whole-disk archive files.)

     Some extensions indicate a filetype recognized by Apple II ProDOS; but, often, the extension is just for user information or to help some utility recognize the file as one it can deal with. For such files the actual ProDOS filetype is usually TXT, BIN, or SHK.

        What is it?  (What program do I use?)
 .2MG   also .2IMG- XGS IIgs disk image file usually 800k or
        larger (GS ASIMOV2; PC Imgutnew.exe)
 .AAF   Apple Archive Format [TEXT] for source code (aaf.unpacker)
 .ACU   NuFX Applelink archive (ShrinkIt*)
 .ALU   usually a multi-file, non-compressed A2 archive (ALU)
 .APF   GS super-res "Apple Preferred" packed graphics format
        (Platinum Paint, Convert 3200, etc.)
 .ARC   PC Archive (GS-ShrinkIt* or DeArc2E or PC Arc program)
 .BMP   Windows Bit-Mapped graphics format (GS Convert 3200;
        many PC viewers)
 .BNX   NuFX with BLU header. (ShrinkIt*)
 .BNY   BLU archive. (ShrinkIt*)
 .BQY   NuFX with BLU header. (ShrinkIt*)
 .BSC   BinScii file. [TEXT]  (BinScii or GScii)
 .BSE   A GSHK* .SEA file with a Binary II header (ShrinkIt*)
 .BSQ   BinScii'd NuFX file. [TEXT]  (BinScii plus ShrinkIt* on
        the result)
 .BXY   NuFX archive with a Binary II header. (ShrinkIt*)
 .CPT   Compactor Pro archive (Compactor Pro on a Mac only)
 .DIMG  Diskcopy disk image file usually produced by a 
        Mac (GS Clone or Diskcopy; Mac Diskcopy; PC Imgutnew.exe)
 .DO    a .DSK file specified as having data in "DOS 3.3 Order"
        i.e. uses DOS 3.3 sector ordering (A2 DSK2FILE and GS ASIMOV)
 .DSK   standard emulator disk image-- length is 143360 bytes for
        5.25" disk images (A2 DSK2FILE and GS ASIMOV)
 .EXE   A2 Executioner file [TEXT]. (On A2; some files may EXEC
        properly under only DOS 3.3.)
 .GIF   Graphics Interchange Format: Compressed picture (IIGIF for
        //e; Super Convert, ... on GS; PC, etc.: many viewers
        and editors)
 .GZ    GZip PC archive format often used for storing A2 emulator
        disk images (GS GZPK v2 plus PMPUnZIP or Angel; PC WinZIP)
 .HDV   Raw (DSK) ProDOS ordered disk image file 800K or greater in
        size; used by emus as a virtual hard disk (ASIMOV2 on IIgs)
 .HQX   Mac BinHex file. [TEXT] (BinHex on Mac or GScii)
 .HTM   HTML [TEXT] with embedded Text commands (Web
        browsers, web editors, etc.)
 .IMAGE Diskcopy images (see .DIMG)
 .IMG   Type IMG or "user #7" Copy II Plus disk image file (A2
        Copy II Plus v6.x or v7.x)
        .IMG is sometimes used for Diskcopy images (see .DIMG)
 .JPG   PC JPEG hi-res, hi-color graphics format (GS JPEG.VIEWER,
        etc. B/W only or PC, Unix viewers)
 .LBR   a multi-file, non-compressed A2 archive (Librarian)
 .LHA   LHA Archive (PC/Amiga LZH program)
 .LZH   LZH Archive (PC/Amiga LZH program)
 .NIB   emulator disk image (typical length: 232960) for protected
        5.25" software (A2 Saltine's Super Transcopy)
 .PCX   PC graphics format (GS Convert 3200; PC many viewers)
 .PD    compressed GS multi-palette graphics file w/o
        palettes (GS SuperPac)
 .PNG   PC PING hi-res, hi-color graphics format (PC viewer)
 .PO    a .DSK file specified as having data in "ProDOS Order"
        i.e. uses ProDOS sector ordering (A2 DSK2FILE and GS ASIMOV)
 .PS    compressed GS multi-palette graphics file with
        palettes (GS SuperPac)
 .QQ    BLU archive.  (ShrinkIt*)
 .SDK   ShrinkIt disk image, usually NuFX-compressed (ShrinkIt*)
 .SEA   Self-extracting A2 ShrinkIt* or Mac ShrinkIt archive
        (depending upon kind, run on Apple IIgs or Mac)
 .SHK   usually an A2 NuFX-compressed archive; non-A2-compatible
        Mac .SHK archives also exist (GS ShrinkIt* / Mac unshrinker
        utility / PC Nulib-- does not extract GS resource forks)
 .SIT   Mac StuffIt archive. (Stuffit on Mac or GS ShrinkIt)
        GS-ShrinkIt will not decode StuffIt Deluxe files.
 .TAR   Unix Tape Archive (Unix tar with -xvf option, GS EXE tar)
 .TGZ   Gzipped .TAR file
 .uu    Unix uuencode file [TEXT] (//e uudecode, Unix uudecode)
 .uue   Unix uuencode file [TEXT] (//e uudecode, Unix uudecode)
 .TIFF  Graphics format (GS SHR Convert)
 .TXT   [TEXT] An ASCII text file (Text editors,
        word processors, etc.)
 .UU    Unix uuencode file [TEXT] (A2 uudecode or Unix uudecode)
 .UUE   Unix uuencode file [TEXT] (A2 uudecode or Unix uudecode)
 .Z     Compressed file (GS-ShrinkIt or Unix uncompress)
 .ZIP   PC Zip Archive (GS PMPUnZIP or UNZIP [GS Shell EXE]
        or PC WinZIP, PKUNZIP, Unix unzip)
 .ZOO   PC Zoo Archive (GS-ShrinkIt??? or PC ZOO program)

* Note: GS-ShrinkIt (= GSHK) can handle all ShrinkIt files except
        .SDK (shrunken disk) files of 5.25" DOS 3.3 disks created by
        8-bit ShrinkIt. 8-bit ShrinkIt does not work for GS
        files having a resource fork or GS .SEA files.


From: Apple's ftp site ...

Most files are in one of a few common formats, and many are a combination.

 .sit    StuffIt 1.5.1 archives
 .hqx    BinHex 4.0 file
 .bin    Binary file
 .image  Diskcopy 4.2 image file
 .txt    plain ASCII text file
 .bsc    Apple II BinSCII file
 .shk    Apple II ShrinkIt file

     Most of the Macintosh files are BinHexed StuffIt files.  This means you need to transfer the file, then read the license agreement which is prepended to it (with any text processor), use BinHex or any utility which can read BinHex 4.0 files to decode the BinHex to a StuffIt archive, then use UnStuffIt or the StuffIt Expander (or a similar utility) to decompress the .sit file into the final file.

     In some cases the final file is a .image file. These are exact duplicates of floppy disks (with verified checksums). Use Diskcopy to convert these files into floppy disks for installation. Some Apple System Software is in this format.

     Most of the Apple II files are either straight text or BinSCII'd ShrinkIt files. This means you need to transfer the file, then use BinSCII to convert the .bsc file to a ShrinkIt file, then use ShrinkIt to create the final file or disk.

Note: Apple calls their BinSCII'd .SHK files ".bsc" instead of ".bsq". It is fairly common for uploaders and ftp sites to tag any BinSCII'd file as ".bsc". The rationale is that, once a user un-BinSCII's a file, he or she will find an .SHK, .ZIP, etc. file and know how to continue.


From: David Kopper

016- How do I tell what kind of file this is?

Here is a simple guide to help you identify a file. You should always go by filename extension first, but not everybody uses those. In Unix, you can use the 'head' command to look at the first couple of lines of a file. If it turns out to be a binary file, you may be in for a surprise. You may want to use the Unix 'file' command to find out if it is a text file or not first. Once you have identified the file, check the earlier info on filename extensions for how to deal with it.

If there are lines in the file that look like this (there can be other text before it--search for 'FiLeStArT'):


then you've got something encoded by BinSCII. You must decode _all_ the parts using BinSCII. Then, if the resulting file is in some compressed form, you would use an appropriate utility to uncompress it. (For example, you would use 8-bit ShrinkIt to uncompress a whole-disk .sdk archive file.)

On the other hand, if you have a binary file which resembles:

NuFilei][![/#NuFX_<:c[[[ H`F-fGSCII~[

then you have a NuFX file (note the key words NuFile and NuFX).  You should be able to extract the files it contains using ShrinkIt.

On the third hand, if you have a text file which resembles:

begin 666 nonsense.bny
M4W5N3U,s4F5L96%S92 T+C$s\%-$4U0V,"Ds(SsZ(%1U92!/8W0s.2 Q,CHS
M...3HT.2!%1%0s,3DY, HT

then you have a uuencoded file.

On another hand, if you have a text file which begins with

(This file must be converted with BinHex 4.0)

then you have a BinHex file. The GScii NDA by Derek Taubert decodes BinHex files on an Apple IIGS. You can also use a variety of macintosh programs to do the decoding. There is also a Unix implementation of BinHex called mcvert.

On one more hand, if you have a text file which resembles:

E00:38 A5 FF D0 32 D8 20 8E FD AD 30 BF 8D 6A 0E 20
E10:00 BF C7 6D 0E 0D 80 02 D0 1D 20 00 BF C5 69 0E

and more lines like that, followed by a bunch of lines that look like:


then you have an Executioner file.


From: Rubywand

017- How can I create 'blank' .dsk, .nib, etc. disk images?

     The simplest way to get a new .dsk or .nib is to copy an existing one and delete the files. Under Windows, you can just Right-click drag-and-drop a file in the same folder to get a copy. If you want a DOS 3.3 formatted image, pick a DOS 3.3 image to copy. If you want a ProDOS formatted image, pick a ProDOS image to copy. You can use a utility like Copy II Plus v7.4 to delete the files.

     If you want a DOS 3.3 image, it's a good idea to boot DOS 3.3 and INIT HELLO the new image. This guarantees that the new image is correctly formatted. Doing an INIT also allows you to pick the version of DOS 3.3 that the new image will boot-- i.e., it will be the version of the DOS 3.3 (e.g. regular DOS 3.3, ProtoDOS, EsDOS, ...) which does the INIT. And, the INIT command allows you to set Volume Number on a .nib (which may be important if the image is supposed to work with a game, etc. which looks fo
r a particular Volume Number).

     DOS 3.3's INIT works fine as a way to format images; but, the routines used by many utilities are not reliable. In general, you should be wary of using utilities like Copy II Plus and Apple's ProDOS Utilities to handle formatting of images on an emulator.

     Another way to obtain fresh disk image files is to download 'blank' .dsk and .nib images from the Apple II archives which offer them.

     However you create or obtain a 'blank' disk image of the sort you want, once you have one, you can save future bother by making multiple copies of it-- e.g. via multiple drag-and-drop copies-- and naming the copies something like "D33blank1.dsk", "PDblank1.dsk", "D33blank1.nib", etc..


018- How can I convert .dsk image <--> .nib image?

     You can use a whole-disk copier such as Disk Muncher to copy from one to the other. For .nib --> .dsk, the .nib must not be a copy protected image.

     For a .dsk --> .nib copy on an emulator using most whole-disk copiers, one result will be to set the Volume Number of the .nib to the default assigned to the .dsk. For example, converting a normal .dsk image this way will result in a .nib with VN set to 254.

     If you want to 'convert' from .dsk to .nib without changing the VN of the .nib, use a copier that transfers just the contents. The old Apple program, COPYA, will do this if the program is modified to eliminate formatting of the target disk. Change the Line which does the INIT (usually Line 250) to ...

250 FT= 1


019- How can I convert Diskcopy images to diskette or to other formats?

     Diskcopy is a Mac disk image format with names ending in ".dimg", ".img", ".image", or with no suffix. (Sometimes, incorrectly, ".dsk" is used.)  The typical length of a Diskcopy file used for an Apple II 800k image is 838,484 bytes*. On a Mac, you can use the Mac Diskcopy utility to convert diskettes to images or images to diskettes.

     On a IIgs, you can use Clone or Diskcopy to convert a Diskcopy image to diskette. (It may be necessary to set filetype to $E0 and auxtype to $0005 in order for the file to be recognized as a Diskcopy image.)

     Clone is more user-friendly. Both utilities work fine for converting Diskcopy images (such as those on the Golden Orchard CD)  to 3.5" diskette. If the Diskcopy file was created under a version greater than 4.2, you will probably need to do any conversions on a Mac which can run a later version of Diskcopy.

     On a PC, the XGS utility Imgutnew.exe can be used to convert most available Diskcopy images of Apple II software to 2MG image format. The Diskcopy image name may need to be changed (spaces removed, etc.) to fit PC DOS format in order for Imgutnew.exe to work.

*See ...  Size Note: Transferring to 3.5" disk (at bottom of this page)


From: Charlie Danemark and Andy McFadden

020- How can I move .shk and other kinds of files to/from .dsk
     and .2MG disk images?

     If you are using Windows 95 ('98, 'Me) you can use FishWings or CiderPress to import .shk and other kinds of files onto .2MG or .dsk disk images formatted for ProDOS. You can also export files from disk image to your PC.


From: Rubywand

021- How can I unfork forked files on my Apple II?

     You can do it 'by hand' using a block editor to change filetype, etc. information in a directory block; or, you can use UnforkIt. UnforkIt is a BASIC program by Ivan Drucker which splits a forked file into two files, neither of which is forked.


From: George Rentovich

022- How can I mount disk image files directly under GS System
     just like any other volume?

     Brutal Deluxe has released MountIt, a program for the IIgs to run disk images directly. You can store disk images without any conversions and run them on your IIgs just like with an emulator on a IBM or Mac. So if you've been thinking of adding a hard disk, MountIt helps with that decision.

MountIt (v1.2) by Antoine VIGNAU and Olivier ZARDINI, August 2009

- MountIt is a Permanent Init File. It handles ProDOS-based .dsk, .po, and .2mg disk images as volumes on the IIgs. Disk image files can vary in size from 32kb up to max available RAM.

- Up to sixteen volumes can be added to the system.

- MountIt mounts volumes as read-only if the disk image file is locked. Otherwise, the volume is mounted as read/write allowing read, write, and format operations.  

- MountIt does not run under ProDOS 8. A switch to P8 will remove any drivers from memory.

- The MountIt package contains an Installer which will copy MountIt to your startup disk. The program source code can be found in the Documentation folder.

Download MountIt 1.2 at .


Size Note: Transferring to 3.5" disk

     Although 2MG, Diskcopy, and some other 800k image formats have file sizes greater than 800k, on a ProDOS diskette they will often occupy a good deal less space. You will often be able to transfer such files (e.g. via a NULL modem connection) to an Apple II 800k diskette so long as you employ a protocol which does not pre-send size information, such as X-modem.
ction) to an Apple II 800k diskette so long as you employ a protocol which does not pre-send size information, such as X-modem.

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Last Update March 27 2014 @ 02:11 PM