X1541

An X1541 cable and similar cables can be used from a PC to access IEC devices on the Commodore-specific serial bus.

Use cases

Typically, a PC connects to a floppy drive like the 1541 via an X-type cable in order to copy data to and from disks. The cable also allows it to access printers and other serial devices.

With some of the cables and appropriate software like the 64HDD and 1541EMU, the PC can also emulate a floppy drive for the C64. But because of the timing difficulties (the PC must react within microseconds), this is somewhat delicate and not always possible using modern non-realtime multitasking operating systems.

The X-type cables are alternatives to modern replacements for disk drives like the 1541 Ultimate or the SD2IEC, which are much more comfortable for day-to-day work on the C64, but also more expensive and more elaborate in construction compared to the more simple cable adapaters.

Serial cable

These adapters, which need to be connected to the parallel (printer, LPT) port of the PC, need a genuine parallel port as seen on older PCs. Using e.g. a USB-LPT-adapter instead is not possible. Even PCI cards with USB ports rarely work, at least under Windows (details here and here ).

X1541

The first cable of the series. It needs to be connected to the parallel port of a PC. It's quite old and only works with fairly old PCs (about up to when the Pentium CPU was standard). The parallel port should, BIOS permitting, be switched to SPP or PS/2. EPP/ECP doesn't work with this adapter. Old, not recommended.

XE1541

In contrast to the X1541, the XE1541 is also compatible to most of the newer parallel ports. No more than one device should be connected when using this cable, adding additional devices will lead to problems with high probability. Old, not recommended.

XM1541

The XM1541 is similar to the XE1541 in principle, but allows using interrupts on the PC instead of polling. No more than one device should be connected when using this cable, adding additional devices will lead to problems with high probability. Not as widely compatible as a XA1541, but still recommended.

XA1541

The XA1541 uses transistors instead of diodes as in the XM1541, and should work with all parallel ports. Recommended.

XA1541F

The XA1541F is a variant of the XA1541 but otherwise compatible. It uses cost-efficient and widely avaiabled FETs (BS170) in place of the difficult to get bipolar transistors of the XA1541. Especially recommended.

XU1541 / USB2IEC

The XU1541-adapter uses USB to connect to PC, realized with an Atmel-microcontroller. The adapter works with a few of the Fast_loader protocols of OpenCBM.

• Homepage for the XU1541

XS1541

The XS1541 connect to a serial port or USB to the PC, and supports both the IEEE-488 and the serial bus of the C64 on the Commodore side. Also supported are the 1571/1581 burst mode and the parallel Speed-DOS adapter. In contrast to the other cables of the X1541 series, there's no need for special software to communicate with the floppy. Instead, the Microcontroller of the adapter deals with the bus communication, while on the PC side a terminal-program as used for modems is sufficient. Via the terminal program, commands for the XS1541 can be entered and files can be downloaded.

Parallel cables

Parallel cables must be used additionally to a serial cable.

XH1541

The XH1541 serves as an addition to the X1541 cable and allows higher transfer speeds.

XP1541

The XP1541 serves as an addition to the X/XE/XM/XA1541 cables.

XUM1541 / ZoomFloppy

The XUM1541 adapter (Homepage) is an extended variant of the XU1541 adapters (s.a.) that also supports parallel cables.

RETRO Innovations offers this piece of hardware under the name ZoomFloppy.

There's also a teensy based variant you can build yourself.

XUM1541 ProMicro using a 32u4 ProMicro board

Software for the cables

• OpenCBM - controls a floppy, Windows and Linux, command line, XM1541/XA1541/XA1541F/XU1541
• Star Commander - controls a floppy, DOS (resp. Windows DOS-Box), more comfortable GUI, alle simple cables
• PRG Mover - Windows XP frontend for various data transfer programs, especially OpenCBM.
• GUI4CBM4WIN Frontend for the command line tools of OpenCBM
• CBMXFer Worthwhile successor of the GUI4CBM4WIN.

Links

• The X1541-series interfaces at sta.c64.org - list of the simpler cables together with building isntructions, additional information and software compatibility matrix.
• Schaltplan des XA1541-Kabel at www.forum64.de - circuit diagram by Birger Hahn of "Emu-Ecke"