Philips P800 family minis

Unfortuantely I know very little about these drives. I certianly don't have the technical manual or anything... I think you need to ispect them and find if the cariage needs locking and if so, how to do it. Oh, and if possible, remvoe the disk pack from the drive before moving it too. As for alignemtn, don't dismantle the heads or positioner unless you have the alignment pack, and don't fiddle with any presets or repalce components in the servo circuit unless you have to. Otherwise no real problems/ Not always... The P850 PSU is a big linear thing (I seem to recall paralleled 2N3055s as pass transistors). I can't comment on the P856 one, I've never seen that series of machines The P851 has a mains trasformer follwoed by regualtor PCBs. Most are linear, I think the 5V oen might be a switching regulator, I would have to check The P854 supply is a full swithcer (or maybe 2 of them). I have the manaul for that, complete with all the waveforms for the chopper circuit. And the wonderful instructions to run the supply off an isolating transformer, but if that's not possible to disconenct the maisn werth wire in the 'scope mains plug and take great care. Err, yes. Having a 'scope floating at mains voltage is not the sort of thing I want to do... There may also be battery backup for the memory suppkies in later machines. I know the P851 (whcih I don;t think you're getting) had an optiuonal PCB carrying 12 NiCd cells and not much else. THe P854 has an option (?) to fit a NiCd pack inside one of the PSUs. You wil lwant ot ispect this for leaking cells, etc. Let me know what you have and we can probably work soemthing out. It appers you're getting a good set of manuals, I would be patient and read through (at least) the heardware manauls before taking too much apart and certainly before pwoering anything up. Yes, I know the exciteemtn of getting a new toy, I also know the pain of damaing it because you didn't Read The Fine Manual (and to be fair, the Philips manuals are pretty good). They look like P854s to me. Those have a keypad frontpanel (controlled by an 8048 iIRC) with vacuum fluorescent displays.Quite fun. My P854 manuals i the preliminary one. In particualr I don't have the microcode sources and I don't have much information on the panel hardware. I hope you get this information, I look forward to reading it. The P854 CPU is quite light (I can easily carry it). The 856 looks a lot heavier (for example, I can lift a P850, but wouldn't want to carry it very far), the driveare probably heavy too. Don;'t forget these thins come apart, though. Pullign all the PCBs makes a suprising difference to the weight, just make sure you know which slots they go back in. Similarly removing the PSUs can help (and you might want to do that anyway to be able to inspect them. -tony