Some years ago I undertook a mission to reimage the XF551 Floppy Drive PCB. The Atari original was a one sided PCB and prone to SIO and solder connection problems in general. I originally created two different versions, one with a modern power supply and the other with as faithful reproduction of the original power supply as possible. As time has gone on some parts became harder and harder to get. As far as I can tell the original crystal cannot be found except in some collector’s grab bag and by scavenging from the original boards. The SIO connectors are facing the same problem. The AC Line Filter from the original power supply version is also no longer available. With the lackluster sales of both assembled versions I decided to discontinue both.
Recently I was approached to redevelop the original power supply version to feature as much as possible of the Atari original parts. I let myself get talked into it. 🙂 This is the final product. It is designed to allow you to salvage most of the parts from the original board, but not all. Primarily the bridge rectifier and transistors will need to be purchased. The bridge rectifier because I used a different size footprint for the part and the transistors because they are cheap to replace and are sensitive to heat from the solder iron. Also check the orientation of the power plug of your donor XF551 board to make sure it matches mine. It appears Atari changed parts in the middle of a production run and I have tried to account for both versions I am aware of, but yours might not fit.
Some chips are soldered to the pcb, but you will need to purchase 1 40 pin and 2 28 pin IC sockets. The full list of parts that can be reused or need to be purchased new is in the BOM.pdf. Along with some assembly tips.
This offering is a bare pcb only. No other parts are included in the sale. You will have to desolder parts from the original board you have and transfer them to this new board. You will need to purchase additional parts. I have tested it using the parts I indicate can be safely scavenged. But…… (There’s always a but…) your mileage may vary. If you have a doggy original part, desoldering it could send it over the edge. I tried to keep the part footprints as generic as possible, but if your crystal is bad, the assembled board will not work until you replace it. I encourage you to purchase this oscillator socket from Mouser or where ever you can find it. The power switch is another not generic part footprint.
To add a little additional functionality I have added 2in1 OS selection, internal SIO AUX, OS, Drive # Selection, Reset and Track Display output connections.