The text below is extracted from a text file once written by Darek when he lived in Canada. He moved since, so I left out his old address and other parts that seem irrelvant now. Please respect the copyright of the information presented here. I am making the following information available to you with the understanding that it is for personal use only. I am not giving permission for anyone to manufacture and sell the cables themselves, or distribute my Xformer software for the purpose of helping to sell the cables. Needless to say, the Xformer is shareware and must not be sold by any dealer or individual. I have been notified of certain dealers who are illegally selling my software. If you know of such a dealer, report him to me, and do NOT buy the software, because you will not become a registered user. Non-registered users may use the Xformer software made available through Compuserve, Genie, Delphi, and the support BBSs, and are allowed to make one Xformer cable for their personal use, but are not entitled to any documentation, disk utilities, or future versions of Xformer. I do ask that you register. ***** Below are directions for putting together a Xformer cable. I accept no responsibility for fried machines, so do this at your own risk. Previous hardware experience, or at least previous experience with a soldering iron and screwdriver, is recommended. The Xformer serial cable serves as an interface for 8 bit peripherals. Any self powered peripheral, like an 810 or 1050 disk drive, thermal printer, color plotter, 850 interface, etc. can then be accessed by the ST through either the Xformer emulator or other software. Multiple drives can be daisy chained to the ST, just as with the 8 bit, by using the regular serial cables to connect extra drives. The length of the cable is not critical, since 8 bit serial cables come in various sizes, usually 3 or 6 feet long. They are included with each disk drive, and most dealers have extra cables. You don't really need the black serial cable as a starting point, since what you are really after are the 13 pin trapezoidal female connectors at the ends. Take some wire cutters and cut the cable at one end. You will now have a 3 foot cable with a 13 pin connector at one end and 13 colored wires at the other. If you have a standard Atari cable, the coloring scheme will be as follows: pin 2 - red pin 3 - orange pin 4 - black pin 5 - green pin 7 - purple pin 10 - blue Only 6 of the 13 pins are needed, so disregard the other 7 wires. Not all Atari serial cables have the same coloring scheme, so use an ohm meter to test each wire. The pin numbering is as follows. If you hold the connector so that the row of 6 pins is at the top, and the other 7 pins are on the bottom, the pins are numbered: ------------------------ / 12 10 8 6 4 2 \ /13 11 9 7 5 3 1\ ------------------------------ You now require a male DB-25 connector. These are the 25 pin connectors found at one end of your ST printer cable. In fact, the Xformer cable plugs in into your ST's printer port. DB-25's are easy to find. Radio Shack sells them but you're better off at an electronics dealer, where they'll cost you about $5, including the plastic cover. The DB-25 cables have the pin numbers printed in very small print on the actual connector. If you hold the connector with the 13 pin row on the top and the 12 pin row on the bottom, the pins are numbered as follows: -------------------------------- \ 13 12 through 2 1 / \ 25 24 through 15 14 / \-------------------------/ The pins you need are 1, 3, 5, 7, 11, and 18. The following table shows which colored wire gets soldered to which pin of the DB-25 connector. Again, these are usual colors, but vary from cable to cable, so use an ohm meter to find the exact wires that correspond to pins 2, 3, 4, 5, 7 and 10. 13 pin color DB-25 serial port connector function ------------------------------------ 2 red 3 CLOCK OUT 3 orange 11 DATA IN 4 black 18 GROUND 5 green 5 DATA OUT 7 purple 7 COMMAND 10 blue 1 +5 volts Sometimes the black wire corresponds to pin 6 rather than pin 4. This is okay since both pins 4 and 6 are GROUND in the Atari serial cables. Once soldered, screw the DB-25 covers over the connector, and use the ohm meter once again to test the connections. If you made any mistakes, you could fry your ST! WARNING: do not attempt to do stupid things like plugging the cable into an 8 bit computer, because this is exactly the same as plugging a serial cable between to 800XLs. ( Nothing happens except that you might fry the machines ). Note that the +5 volt line coming out of the ST's printer port is not rated at 50mA (as is the Atari 8 bit serial port), so devices like the Ape Face which pull their power from the computer will not work. This is a similar to the 1200XL serial port, which was also current limited. The only solution is to tap into the ST's 5 volt power supply, which can be easily accessed at the cartridge port. Most 8 bit disk drives and printers are self-powered and thus don't draw current from the computer. To make the ST emulate an 8 bit peripheral, rather than an 8 bit computer, the cable can be rewired by swapping pins 3 and 5 (orange and green, or DATA IN and DATA OUT) in the 13 pins connector. Since the 13 pin connector has snap-in wires, they can be pulled out and rearranged without any soldering. Software needs to be written to support this modification, and I haven't written it because I have no intention of turning my 1040ST into a large disk drive for some silly old Atari 800. (No offense to Atari 800 owners). But it is a possibility if enough people request it. Although more elaborate cables can be devised, this is pretty well the only design that doesn't require additional circuitry or modifications to either the ST or 8 bit. Future versions of Xformer will be able to use the current design of the cable.