Commodore - PC File Transfers

You may have downloaded some C-64 programs from the internet to use on your PC with an emulator. You also may have some of your own C-64 programs you'd like to share with others on the internet. Unless you have a web browser for your C-64, you need some way to transfer the files between the Commodore and a PC

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Big Blue Reader

How do I move files between my PC and Commodore? It's really quite easy with Big Blue Reader (BBR for short). BBR is a program for the C-64 or C-128 which copies files from one disk drive to another. More importantly, BBR can read and write both Commodore and PC floppy disks. Normally a Commodore cannot access a PC disk beacuse PC operating systems use a different scheme to record files onto the disk. Some Commodore compatible disk drives have a built-in MFM controller which is capable of accessing PC disks.

MFM Capable Drives

The DOS firmware included with these disk drives doesn't support access to PC floppies. BBR unlocks this feature by accessing the MFM controller directly. Using BBR with one of these drives you can copy files to and from PC disks. Here's how I do it with my C-128d and 1581:

  1. Load BBR on the C-128d
  2. Insert a 3.5″ floppy disk into the 1581
  3. Format the 3.5″ disk for MS-DOS (PC format) using BBR
  4. Use BBR to copy the Commodore files to the 3.5″ disk
  5. Remove the 3.5″ disk from the 1581 and insert it into the PC's 3.5″ floppy drive
  6. Use MS-DOS or Windows to copy the Commodore files from the 3.5″ disk to the PC's hard disk

To copy files from the PC to a Commodore disk you would first do steps 1,2,3,5 (skip step 4) above then:

  1. Use MS-DOS or Windows to copy the PC files from the PC's hard disk to the 3.5″ disk in the PC's floppy drive
  2. Remove the 3.5″ disk from the PC's floppy drive and insert it into the 1581
  3. Use BBR to copy the PC files from the 3.5″ disk to any other Commodore disk drive

BBR Features


You can get Big Blue Reader from Centsible Software, Computer Bargain Store or Sogwap Software

Modem Transfer

In the old days before the internet, people used their modems to dial into BBS-es with terminal software. You could read messages, email and download files. From a BBS user's perspective, the internet is just one enormous BBS, or an infinite number of smaller ones interconnected.


You can still connect to the internet from your Commodore with a modem to read messages, email and download files. If you're lucky enough to have a Commodore internet connection then you have an easy way to move files from your Commodore to your PC. Just email them!

Eliminate the Middle-Man

Consider the fact that when your modem connects to the internet, it's really just connecting to another modem. The only thing between the two modems is the phone company. You don't need the phone company if both computers are in the same room. By connecting the two modems together with plain telephone wire (RJ-11) you can establish a connection between them. With the correct AT commands and a common protocol you'll be transferring your files in no time

The only problem with this approach is the modems themselves. To enable the highest possible transfer speeds over a plain old telephone line modem technology has evolved through a number of different standards. In theory, each new standard is supposed to support communications with older, slower standards. In practice it doesn't always work that way and you may have problems connecting to a new, fast modem from an old, slow modem

Serial Link

This approach assumes you have an RS-232 serial port on your Commodore. You'll also need terminal software on both computers and know how to use it. The connection is made with a null-modem cable between the RS-232 port of the Commodore and the COM port of the PC. With a little tweaking and some practice you can communicate directly between the two computers without the use of a modem. As a bonus, your file transfer speed will be the highest your RS-232 support chip will allow

Modem and RS-232 Transfer Links

Parallel Port Connection

There are many programs which use a cable connected from the C-64 to the LPT (Parallel) port of the PC. These programs mostly run on the PC and allow the C-64 to access the hard disk of the PC. There are many types of cables and you must use one which your program will recognise. Its up to you to read about each one and decide for yourself

64HDD - Enslave your PC!

64HDD uses a standard XE-1541 cable to connect the serial IEC port of your Commodore to the LPT port of the PC. The MS-DOS software simulates a Commodore disk drive to provides access to PC hard and floppy disks, CD-ROM drives and other devices. Reading and writing to D64, D71, D81, T64, LNX image files is supported. 64HDD also gives your Commodore direct access to MS-DOS files and directories with Long File Name support. Plug-ins are available to enhance the functions of 64HDD and allow programmers to create new features

64HDD Features

I have seen 64HDD demonstrated and it is truly fantastic! 64HDD opens an entirely new area of development for Commodore programmers through the ability to use PC devices directly from an unmodified C-64. The ability to read and write files directly to PC disk drives makes 64HDD the most powerful and flexible solution possible for cross-platform file sharing. 64HDD is actively developed and supported and will most certainly be my future solution of chioce. Learn more on the 64HDD home page


1541Emu is a 1541 disk drive emulator for MS-DOS. 1541Emu uses a special cable to connect any IEC port Commodore to the LPT port of the PC. 1541Emu is a no frills solutions which emphasises 1541 compatibility and speed above all else. Most disk turbos should work with 1541Emu. 1541Emu has potential for power and flexibility but for now there isn't much developed for it

The 1541Emu cable is more difficult to construct and best performance can only be attained by purchasing an expasion card. Although G64 (GCR) image support is mentioned the current incarnation only works with D64 images. 1541Emu requires a faster PC than 64HDD and doesn't have as many features. If 1541 compatibility and speed are your imperatives and you have technical skills then 1541Emu may be a good solution for you


Inspired by the need to load stuff faster and not shuffle disks so much, 64NET/2 is a new incarnation of an older project 64NET v1.xx. The original goal of access to the PC hard disk with D64 support has been achieved. Future goals include providing access to other PC resources like networking. The current version connects to C-64 User Port and work is being done on IEC connection. 64NET/2 is supported by the LUnix (Little Unix) operating system for unexpanded C-64/128. 64NET/2 is still being developed and not much else is documented for it


prlink by Marko Makela is an IRQ driven daemon for C-64, C-128, VIC-20, C-16 and PET computers. PRLink provides access to Commodore memory and disk drives for Amiga, Linux and MS-DOS computers through a cable connected to the PC LPT port. PRLink supports several different cables

Parallel Direct Transfer Solutions


Disk images facilitate the use of disk-based Commodore software on PC emulators. A basic disk image is a sector-by-sector copy of the disk which is written to a simple sequential file. There are disk image types for each major Commodore floppy drive type (1541, 1571, 1581 and FD-2000). Each image type is distinguished by a .Dxx extension appended to the DOS filename of the image

Basic Disk Image Types

Beyond the basic disk image types there are some variations which accomodate sector error information. For 1541 disk images there is an additional variation to store data from tracks 36-40. These variants use the same DOS file extension as their basic image counterparts. The only way to know for sure what kind of image you have is by the file size

Variant Image Types

* I've never encountered these image variations. I'm listing them here for the sake of completeness

The Formats Documents

For an in-depth discussion about all Commdore disk image and archive types you must read Peter Schepers' Formats Documents. In case Peter's homepage is unavailable there is an older version on Fairlight.To


CatWeasel is an interesting solution for Amigas and PCs. CatWeasel is a universal floppy disk controller that uses unmodified PC disk drives to read 3.5″ and 5.25″ floppies. Versions of CatWeasel are available for Amiga Zorro slot, Amiga 1200 clock-port, PC ISA or PCI slots. Connect a PC 5.25″ drive drive to CatWeasel and use it to read your Commodore floppies. A new MK3 model supports connecting original SID chip, digital joystick connectors and an Amiga keyboard connector.

CatWeasel Features

Get CatWeasel

CatWeasel is advertised to support reading even formerly unreadable floppy disks. CatWeasel is the fastest and easiest way possible to create disk images from floppies and write images to floppies. There are drivers for Amiga, Linux, Windows and MS-DOS. You can get CatWeasel from Individual Computers


Wolfgang Moser has written 1581-Copy to create images of 1581 and FD-2000 disks on the PC. 1581-Copy can read/write 1581 and FD-2000 disks in a standard PC floppy drive:

1541 Connection

For disk images to be useful there needs to be a way of reading a floppy from a Commodore disk drive and writing an image file to a PC disk drive. This is accomplished by connecting the PC's LPT port to the Commodore IEC port using an X-1541 cable. This simple, cheap cable combined with the right software enables the PC to read disks from a Commodore drive and write a disk image file onto a PC disk

1541 on the PC

1541-LPT connection has been the defacto-solution for some time. Many different programs use the X-1541 cable and D64 disk images. One caveat to using disk images is that you can't read or write files on a disk image without the software. Neither MS-DOS nor CBM DOS support direct manipulation of files stored in disk images

Star Commander

Star Commander is the tried and true method for archiving 1541 disks on a PC. Star Commander reads Commodore disks from a 1541 disk drive connected to the PC's LPT port and writes a disk image file to the PC's hard disk. Star Commander supports most all X-Cable variants including parallel transfer for maximum speed

Star Commander is actively developed and supported with a large user base. Like 64Copy the Commander can convert between most Commodore image and archive formats. Now, in 0.83 betas, it even has a command line interface like TargetD64 which allows you to do the very same conversions from scripts as well


Peter Schepers' 64Copy is an MS-DOS program for creating, and manipulating Commodore disk images and archives on a PC. 64Copy is an image file converter that handles most all emulator image formats (D64, T64, D71, D81, PC64, X64) as well as Commodore archives (LNX, ARK, LBR, ARC, SDA, SPY, CPK and ZipCoder) and converts between them. It also has a Text/HEX Editor, File Viewer, BASIC unlister, D64 HEX Editor, 6502 Disassembler, Directory Customizer, CheckTape, CheckDisk, CheckZipCode (4 & 6-pack), CheckCRT, CheckG64 and decoding HQX and UU files

64Copy doesn't emulate any Commodore computer or disk drive. It cannot read disks from a real 1541 disk drive. What it does very well is convert one image/archive type into another and allow extracting/inserting of individual files. When you need to move files between images, Commodore archives and DOS directories on a PC disk then 64Copy is indispensable

D64 Editor

D64 Editor by Forrest Mook is a Windows program for manipulating D64 images. D64 Editor is very light on features compared to 64Copy but makes up for that by being brain-dead easy to use. D64 Editor performs these functions:


Karlheinz Langguth's TargetD64 is billed as a universal C64 archive related converter tool and emulator frontend but that is oversimplified. TargetD64 is a command-line tool for Windows and Linux which converts any file or group of files into one or more D64 image files. TargetD64 will extract D64 images from compressed archives or put the file(s) into a newly created D64. The following archive and disk image types can be unpacked by TargetD64:

Karlheinz isn't actively updating TargetD64 anymore but he still supports it. Anyway, it works very well in it's current state. Quite useful for unpacking C-64 archives or when you want to quickly put something into a D64

The C-64 Side

The vast majority of C-64 software on the internet is stored within D64 files. D64 is a simple format and the X-Cable used to make it is easy to construct (plus it has 64 in the name :)) One caveat of this is the size of the image, which is a constant for all disk image types. Even if your disk contains only one program using 1 disk block, the D64 will still record all disk blocks. Most people compress their D64 images using PKZIP or WinZIP to save disk space on internet servers with large numbers of D64s. There was no way to unZIP these PC archives on a real C-64, until recently ...


Pasi Ojala's PuZIP and GunZIP utilities will create and dissolve PC style .ZIP archives made with PKZIP or WinZIP. If the .ZIP archive contains a D64 disk image, GunZIP can automatically rewrite the original Commodore disk contents directly onto a 1541 disk. GunZIP is also capable of unpacking bare D64 images directly to a 1541 disk. Pasi has written versions for C-64, C-128, C-16, Plus/4 and VIC-20


GeoZIP runs under Wheels and is the only ".ZIP" archiver that works with GEOS files. The current version of GeoZIP cannot unpack D64 files onto a 1541 disk because the Wheels Kernal doesn't support it. GeoZIP is primarily useful as a GEOS file archiver but works well with other files


GeoBEAP (Bo's Excellent Archive Program) is an archive and image handling program for GEOS and Wheels. In addtion to it's own prorpietary ".BEP" archive format, GeoBEAP will create (pack) and dissolve (or unpack) many disk image and archive formats

GeoBEAP Features

The LYNX support also includes GeoPack files, making GeoBEAP a direct replacement for that aging application. Future versions of GeoBEAP may add support for Wraptor archives and T64 images. I have met with Bo a couple of times and I can tell you he's one of the most dedicated GEOS programmers around. GeoBEAP can also be obtained from LoadStar

UnZIPv2 and D64it

Errol Smith's UnZIPv2 utilities for PKZIP and .GZ are similar to GunZIP. UnZIPv2 functions as an unpacker only, it will not create new archives. Like GunZIP, UnZIPv2 will unpack a ZIPped D64 archive directly to a 1541 disk. His D64it utilities will create D64 images from 1541 disks. D64it can also unpack D64 images onto 1541 disks. Errol has written versions for C-64 and C-128


Wraptor has the distinction of being one of only three programs which can successfully archive GEOS files. Wraptor archives are mostly found on LoadStar disks since that's where it is developed and supported.

Wraptor has some drawbacks including a clumsy user interface and intolerable slowness. More importantly, if you use Wraptor for GEOS files please make sure you have the latest version (3b as of this writing). Early versions of Wraptor had nasty bugs when they encountered certain GEOS file structures. Although Wraptor is still useful, a better solution for GEOS file archiving is GeoZIP


ZipCode is a whole disk archiver which breaks a 1541 disk into four zones and copies each zone into a file. Each file is lightly compressed and written to a disk in another drive. Sometimes when you download a D64 file it will contain a ZipCoded archive of another disk. You can identify ZipCode archives because each of the four files will be prefixed by a digit (1-4) and exclaimation point:

A ZipCode Archive

2    "1!GALAXIAN.Z64"   PRG
21   "2!GALAXIAN.Z64"   PRG
24   "3!GALAXIAN.Z64"   PRG
3    "4!GALAXIAN.Z64"   PRG

The suffix ".Z64" distinguishes the ZipCoded files but is optional. ZipCode archives are common but ZipCode is obsolete. For best compression and widest compatibility, please use PuZIP to make your whole disk archives


Lynx gathers files into a single archive file where only blocks allocated to files are stored. Lynx supports no compression and no Random-access files. Lynx is problematic because there are several versions of the utility and some produce non-standard archives. You can't reliably unpack a Lynx with a different version of the utility than the one that made it. Some versions of Lynx have bugs which can create corrupt archives

You can identify Lynx archives by the ".LNX" extension. Lynx archives are common so you'll need the Lynx utility (possibly all versions of the utility) to unpack them. Lynx is very obsolete and should not be used to create new archives. To avoid problems and maximize compression, please use PuZIP to make your file archives


Convert is the original GEOS file archiver included in GEOS 2.0. It converts GEOS VLIR files to simple sequential files and nothing more. Some GEOS programs on the web are distributed in Convert format. Convert files use the ".CVT" file extension.

If you have GeoWrite documents you'd like to use in Windows (ie with Microsoft Word) Convert can help. Make a .CVT file from your GeoWrite document and use one of the methods above to copy the .CVT file to your Windows machine. Then download Maurice Randall's GeoWriteImport to process the .CVT. GeoWriteImport is a Windows program which will translate the .CVT-ed GeoWrite document into a plain ASCII file, readable by any PC word processor

Other C-64 Utilities

File Transfer Resources


This page was last updated April 4, 2004
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