The X1541-series interfaces

For a complete list of cables and adaptors discussed on these pages, see the cables and adaptors page. If you're having problems with a cable then download XCTest and test your cable with it.

The descriptions and construction guides on these pages are for beginners. If you are a hardware expert then, please, bare with them.

The interfaces

There are four serial cables and two additional parallel cables. These all connect Commodore drives to the PC parallel port. Also, using the serial cables, you can connect a Commodore machine to the PC, too. Depending on what Commodore and PC hardware you have, what operating system you are running on your PC and what transfer speed you want to achieve, you may select among a number of cables and cable pairs. For a detailed guide on selecting, see below.

The cables are the following. For more infos on each cable, follow the link on the cable name.

X1541-series serial cables

These are absolutely necessary, no data transfer will work without them.

X1541-series parallel cables

These are optional cables, companions to the serial cables, you can't use them alone. All they do is speed up the data transfer.

X1541-series cable combos

These Y-shaped cables combine a X1541-series serial cable with an X1541-series parallel cable.

X1541-series adaptors

The following adaptors convert an X1541-series cable to another.

The following are the equivalents of the X1541-series cable combos. You can plug a Commodore serial cable and, optionally, a Commodore parallel cable onto the adaptor and then plug the adaptor into the PC. This way, you can use the Commodore cables, that you already have, with a PC, too.

If you'd like to buy parts for the cables and adaptors, see the electronical parts page. If you'd like to order any of these cables or adaptors then, please, visit The X1541 Shop.

Cable selection guide

If this is the first time you encounter the X1541-series cables then it is highly recommended that you read through this whole section. However, if you don't have time for that or this is too much information for you, you may jump to the conclusion right away.

Serial and parallel cables

To be able to transfer data between your Commodore drive and your PC, first, you need a serial cable. Note that serial here means that the cable is serial, even if you connect it to the parallel port of the PC. You have four choices:

If you have the serial cable finished and the transfer software up and running with it and you have a Commodore 1541, 1570 or 1571 drive or compatible clone, you may think of speeding the transfer up with one of the additional cables. Please, note that all these cables need modifications in your Commodore drive. If you're not good at hardware hacking, don't try doing it yourself but ask for an expert's help instead. Also, read the transfer software's documentation on whether it supports these cables. You have two choices:

The following charts describe the compatibility of the cables with different parallel ports and software and how the cables can be used together. This section should be considered as the central collection of the information that you can find on the info pages of each cable.

Compatibility with each other

The serial cables can be used alone. (That is, unless the chosen software requires a parallel cable.) Parallel cables cannot be used alone, they require the presence of a serial cable. However, not all pairs of serial and parallel cables are possible. In general, you should not use the XH1541 hybrid cable at all as it was designed to bring the most out of old PC hardware only. It has been superseded years ago by the XP1541 parallel cable that gives you higher speed on a modern PC and can be used along with all serial cables.

Serial cable/parallel cableXH1541XP1541
X1541 cable YES YES
XE1541 extended cable no YES
XM1541 multitask cable no YES
XA1541 active cable no YES

Compatibility with PC parallel port modes

For most integrated parallel ports on modern PC's, the mode of your parallel port can be viewed and changed in the BIOS setup. For old parallel port cards, you may have to use jumpers or its own software. It may be possible that the BIOS setup or the parallel port software calls parallel port modes differently: "Standard", "Compatible" or "Normal" usually stand for SPP; "BPP" or "Extended" for PS/2. Some BIOS'es display the parallel port mode incorrectly so, after having changed it, check the correct mode as reported by XCTest or The Star Commander.

The very old X1541 cable does not work with the integrated parallel ports of modern PC's, therefore, you should choose it only if you want to use it with an old software and have an old PC for this purpose. The XE1541 extended cable and the XM1541 multitask cable have better compatibility with modern PC's but they may have problems with laptops and a few desktop motherboards (more details on the info pages).

The XA1541 active cable has the best compatibility with parallel ports. Also, the integrated parallel port of modern PC's are all compatible with the XP1541 parallel cable. If you concentrate on hardware compatibility, these two cables are the best choices.

Cable/port mode SPP PS/2 EPP/ECP
X1541 cable [1] YES YES no
XE1541 extended cable [2] YES YES YES
XM1541 multitask cable [2] YES YES YES
XA1541 active cable YES YES YES
XH1541 hybrid cable YES YES YES
XP1541 parallel cable no YES YES

Notes:

  1. You can check if your parallel port is compatible with the X1541 cable with X1541Test.

  2. We found that the this cable doesn't work on certain motherboards and laptops. See the info page more details. On incompatible machines, it is recommended that you use the XA1541 active cable instead. Unfortunately, there's no software that would be able to tell whether your parallel port is compatible with this cable or not.

Following is a compatibility chart of possible combinations of serial and parallel cables with parallel port modes.

Cable combo/port mode SPP PS/2 EPP/ECP
XXH1541 = X1541 + XH1541 YES YES no
XXP1541 = X1541 + XP1541 no YES no
XEP1541 = XE1541 + XP1541 no YES YES
XMP1541 = XM1541 + XP1541 no YES YES
XAP1541 = XA1541 + XP1541 no YES YES

You may find more information about parallel port modes on The PC parallel port page.

If you are interested in the electronical details of PC parallel ports and the X1541-series cables, please, read the Technical background information section in The Star Commander documentation.

Compatibility with PC software

There are two categories for current software, according to the main functionality. A transfer software makes the PC act as a Commodore machine – the master of the serial bus –, letting you access the contents of disks in attached Commodore drives from the PC. A file server or emulator makes the PC act as a Commodore drive – a slave on the serial bus –, letting you access the contents of emulated disk drives from the Commodore machine.

In the past, the XE1541 extended cable was supported by the most software. However, this changed with the introduction of native GNU/Linux and Windows software which support the XM1541 multitask cable and the XA1541 active cable instead. NOTE: An XE1541 extended cable can easily be converted into an XM1541 multitask cable (more details on the info page). Some of the software support the XP1541 parallel cable, as well.

Software/cable X1541XE1541XM1541XA1541XH15x1XP15x1
1541EMU [2] no no no no no no
64HDD YES YES no no no no
C64S Emulator [1] YES no no no no no
cbm4linux no no YES YES no YES
OpenCBM/cbm4win no no YES YES no YES
Disk64 [1] YES no no no no no
nibtools no YES no [3] YES no YES
mtap & ptap YES YES no YES no no
prlink YES no no no no no
The Star Commander YES YES YES YES YES YES
Trans64 [1] YES no no no no no
VC1541 [1] YES YES no no no no
X1541 [1] YES no no no no no

Notes:

  1. This software has been abandoned. It is not developed anymore, therefore, you should not choose cables according to their compatibility with it. Instead, use another software for the same purpose and see the compatibility of the cables with that one.

  2. This software uses its own cable and it does not support any of the X1541-series interfaces. It is included in the table only for the sake of completeness.

  3. Support for this cable is currently not available in this software but it is planned to be implemented later.

Also, a software compatibility chart for cable combos. Only those software are included that support, at least, one of the X1541-series parallel cables.

Software/cable combo XXH1541XXP1541XEP1541XMP1541XAP1541
cbm4linux no no no YES YES
OpenCBM/cbm4win no no no YES YES
nibtools no no YES no [1] YES
The Star Commander YES YES YES YES YES

Notes:

  1. Support for this cable combo is currently not available in this software but it is planned to be implemented later.

Finally, a compatibility chart between software and non-X1541-series cables. Only those software are included that support, at least, one non-X1541-series cable. This cable is included only for the sake of completeness. You can find the descriptions of these cables on the cables and adaptors page.

Software/cable 1541EMUPower-
Loader
1541EMU YES no
64HDD no YES
prlink [1] no no

Notes:

  1. This software supports a wide variety of cables. See the software documentation for more information.

Compatibility with PC operating systems

Strictly speaking, the cable has nothing to do with the operating system. However, it is possible that the software, that runs under a given operating system, supports only a few cables, not all of them; or, vice versa, the software, supporting a given cable, may run under only a few operating systems, not all of them.

While transfer programs may or may not run properly in multi-tasking environments, such as GNU/Linux, OS/2 or any version of Windows, you must be prepared to boot real DOS on your PC to run file servers and emulators.

The following table shows the compatibility between PC software and PC operating systems. This table is for informational purposes only; because there are so many clones of the original MS-DOS and because there are so many versions of GNU/Linux and Windows, you should see the software documentation for more precise details on compatibility with different operating systems.

Software/operating system DOS Linux W9X/MENT/2K/XP
64HDD YES no no no
C64S Emulator [1] YES no no no
cbm4linux no YES no no
OpenCBM/cbm4win no no no [2] YES
Disk64 [1] YES no no no
nibtools YES no no no
mtap & ptap YES no no no
prlink YES no no no
The Star Commander YES yes[4]YES[3]yes[4]
Trans64 [1] YES no no no
VC1541 [1] YES no no no
X1541 [1] YES no no no

Notes:

  1. This software has been abandoned. It is not developed anymore, therefore, you should not choose cables according to their compatibility with it. Instead, use another software for the same purpose and see the compatibility of the cables with that one.

  2. Support for this operating system is currently not available in this software but it is planned to be implemented later.

  3. Steps have been taken in this software to support this operating system. Read the software documentation for instructions and more information.

  4. Steps have been taken in this software to support this operating system but it is, unfortunately, not perfectly stable. Read the software documentation for instructions and more information.

Joining the compatibility table of cables and software with that of software and operating systems, the result is a compatibility table between cables and operating systems.

Cable/operating system DOS Linux W9X/MENT/2K/XP
X1541 cable YES yes[2]YES[1]yes[2]
XE1541 extended cable YES yes[2]YES[1]yes[2]
XM1541 multitask cable YES YES YES[1] YES
XA1541 active cable YES YES YES[1] YES
XH1541 hybrid cable YES yes[2]YES[1]yes[2]
XP1541 parallel cable YES YES YES[1] YES

Notes:

  1. Steps have been taken in The Star Commander to support Windows 95/98/ME DOS shells. Read the software documentation for instructions and more information. Also, support for Windows 95/98/ME is currently not available in openbm/cbm4win but it is planned to be implemented later.

  2. Steps have been taken in The Star Commander to support GNU/Linux dosemu and Windows NT/2000/XP DOS shells but it is, unfortunately, not perfectly stable. Read the software documentation for instructions and more information.

Compatibility with Commodore drives and machines

Don't let the "1541" in the names of the cables fool you: all the serial cables – X1541, XE1541, XM1541 and XA1541 – are compatible with all Commodore drives that have the usual serial port; this includes 1541, 1570, 1571 and 1581 drives and compatible clones and other Commodore drives, too. Also, the serial cable can be plugged into the serial port of a Commodore machine, as well, making the PC emulate Commodore drives; this includes all C64 and C128 flavors. However, it is up to the software whether it can transfer from/to a particular drive or whether it can emulate it. As the 1541 drive is the most popular of all, you can expect all transfer and emulator software to support or emulate it; see the software documentation about support of other drives.

As for hardware compatibility, the XA1541 cable simulates the circuitry found in the serial bus ports of Commodore machines and drives. For this reason, it can cope with multiple devices on the same serial bus, daisy chained with plain Commodore serial cables from the first one that the X1541-series cable is connected to. On the other hand, the XE1541 and XM1541 cables cannot drive the serial bus strong enough in such cases: the result is unreliable data transfer, damaged or lost data. But, for a single Commodore machine or drive connected to the PC, any of the serial cables will do.

The parallel cables are available in two flavors each: the XH1541 and XP1541 cables are for 1541 drives, the XH1571 and XP1571 cables are for 1570 and 1571 drives. The 1541 and 1570/1571 flavors are identical in concept and usage, only their implementation differs, because of the hardware differences between 1541 and 1570/1571 drives. There are no known similar implementations of parallel cables for 1581 drives or other Commodore drives. If you need an additional parallel cable between the PC and a Commodore machine, use the Power-Loader cable instead.

The following cable shows the compatibility between the transfer software and different Commodore drives; "+P" means that an additional parallel connection, via an XP1541/XP1571 parallel cable is also supported. The Commodore drives are supposed to be running in their native mode; the 1541 emulation mode of 1570 and 1571 drives is considered to be identical to genuine 1541 drives.

Transfer software/drive 1541 1570 1571 1581
cbm4linux YES+P YES+P YES+P no
OpenCBM/cbm4win YES+P YES+P YES+P no
Disk64 [1] YES no no no
nibtools YES+P no no no
mtap & ptap [2] no no no no
prlink YES no no no
The Star Commander YES+P YES+P YES+PYES[3]
Trans64 [1] YES no no no
X1541 [1] YES no no no

  1. This software has been abandoned. It is not developed anymore, therefore, you should not choose cables according to their compatibility with it. Instead, use another software for the same purpose and see the compatibility of the cables with that one.

  2. This software has been designed to transfer data from/to Commodore datasettes, therefore, it does not support any Commodore drive. It is included in the table only for the sake of completeness.

  3. Not all functions, related to this drive, have been implemented in this software. See the software documentation for the current implementation status.

The following table show which drives file server or emulator software can emulate; "+P" means that an additional parallel connection, via a Power-Loader cable is also supported; "+T" means that (most!) disk turbos are also supported.

Server software/drive 1541 1570 1571 1581
1541EMU [2] YES+T no no no
64HDD YES+P YES+P YES+P YES+P
VC1541 [1] YES no no no

  1. This software has been abandoned. It is not developed anymore, therefore, you should not choose cables according to their compatibility with it. Instead, use another software for the same purpose and see the compatibility of the cables with that one.

  2. This software uses its own cable and it does not support any of the X1541-series interfaces. It is included in the table only for the sake of completeness.

Compatibility with Commodore software and disks

The serial cables are intentionally of simple design and do not aim at achieving the highest transfer speeds possible.

Transfer programs, that use the serial cables, should be able to transfer a single side of a 1541 disk in a few minutes, depending on the transfer mode (the disk turbo and the data transfer protocol) used.

Emulator and file server programs, that use the serial cables, cannot and, therefore, do not support disk turbos, only the standard Commodore IEC transfer speed. It may be possible, though, that the emulator software itself contains its own disk turbo (in a routine that invisibly autoloads and autostarts before the actual program being loaded) or it can detect GEOS running in the Commodore machine and can tell GEOS how to use the emulated drive at a higher speed. See the software documentation for such information. If you need a cable that lets software emulate Commodore drives at a very low level and support (some!) disk turbos, use the (more complicated) 1541EMU cable instead.

With an XP1541/XP1571 parallel cable added to the serial cable, you can not only raise the transfer speed but also make it possible to transfer the disk contents at a lower level: read more data more precisely off the disk. The only current example for the latter is nibtools, which is a nibbler software for 1541 drives that runs on a PC.

Compatibility with Commodore disk-based copy protections

With a transfer software and a serial cable only, you may be able to transfer simple copy protections: intentional disk errors and intentionally damaged sector contents. However, for more sophisticated ones, you need an XP1541/XP1571 parallel cable and nibtools.

There is currently no file server and emulator software that would be able to emulate copy protections, with or without a parallel cable.

Conclusion

Not all software may support the cable of your choice. As you can see above, not all software support all cables (or cable combos). If you make your choice according to hardware compatibility but your favorite software does not support the chosen cable (or cable combo) then you may want to ask the author to incorporate support. However, if the software is not developed anymore or your request for support is rejected or ignored then you have to make a compromise between hardware and software compatibility. Also, your cable choice may be based on the fact that your goal can be achieved with a single software only.

The XM1541 multitask cable is the best compromise. On a modern PC, the best compromise for software and hardware compatibility is the XM1541 multitask cable because:

You can convert an XE1541 extended cable into an XM1541 multitask cable easily. If you already have an XE1541 extended cable, you can easily convert it into an XM1541 multitask cable, by rewiring it or with the compact XE/M1541 adaptor.

The XA1541 active cable has the best hardware compatibility. If hardware compatibility (including possible compatibility with future PC's) is your absolute priority, the XA1541 active cable is for you. Its advantage over the XM1541 multitask cable is that:

Its disadvantage is that:

It is similar to the XM1541 multitask cable in that:

Add the XP1541/XP1571 parallel cable for higher transfer speeds or for copying protected disks. If you want higher speeds or want to be able to transfer (some!) copy protected disks, add the XP1541/XP1571 parallel cable to your serial cable.

There are, of course, other solutions for transferring data from/to Commodore drives and machines or emulating Commodore drives on the PC but, as those use different cables, they are out of the scope of this page.

Cable construction

If you're not very good at soldering, you can buy all these cables in The X1541 Shop, for low prices.

If you decided that you need an XP1541/XP1571 parallel cable then you should not build it as it is: this cable is a concept rather than an actual cable. It is recommended that you build a Commodore parallel cable instead, which you can either plug into a Commodore machine – thus establishing an additional parallel connection between the Commodore drive and the Commodore machine – or into an XEP1541 adaptor or an XAP1541 adaptor – for a parallel connection between the Commodore drive and a PC.

The XEP1541 adaptor is a small circuit board that has a port for the usual Commodore serial cable and a card edge for the Commodore parallel cable. Plug the Commodore serial cable onto the adaptor, plug the adaptor itself into the PC parallel port and you get an XE1541 cable; if you need an XM1541 cable, use a twisted Commodore serial cable instead of the normal Commodore serial cable (the XMP1541 adaptor has not been implemented); when an XA1541 cable is needed, use the XAP1541 adaptor instead. If you also plug the Commodore parallel cable onto the adaptor, you get an additional XP1541/XP1571 parallel cable.

Similar cables

The following cables are similar, in design concept and/or purpose, to the X1541-series interfaces. They are not discussed further on this page as they are out of scope.

Commodore-PC cables

Amiga-Commodore cables

Commodore cables

Copyright and license

The X1541-series cables are copyrighted by the following individuals:

If you produce and sell cables or adaptors that are compatible with these cables – except for the original X1541 cable –, you must give credits to the respective copyright owner or copyright owners. If your adaptors are built onto printed circuit boards then you must also make the complete layout available in a format and resolution that is suitable for high quality reproduction so that people may build the adaptors themselves, if they want.

This common license for the cables is an agreement among the cable authors. However, because the author of the original X1541 cable couldn't be contacted for an inquiry, this license does not apply to the original X1541 cable.

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