[For the benefit of others who may be wondering 'how the heck does he know that', I've received (and answered) a couple of private e-mails about this particlaur PERQ. Since it's been taken to the classiccmp list now, I'll reply here] Shfit-A (or any other key combination) does exactly the same thing to the ROM bootstrap on a T2 as on every other classic-PERQ. Namely nothing. commented sources to the T1 or T2/T4 bootstraps), the sequence is : 1) CPU initial diagnostics. If these fail, the machine goes into an endless loop, the DDS will be <10 2) Attempt to boot from the PERQlink (16 bit parallel port on the OIO card), floppy drive nand then hard disk in that order. The machine conventionally loads VFY and SYSB from the appropriate disk. VFY is more extensive system tests (including main memory), SYSB is the bootstrap. Now, IMHO the POS SYSB is broken-as-designed because, in the abscence of a keypress, it tries to load the first interpretter microcode drive). IIRC the PNX boot does things properly and loads the rest of the system from the decvice that it was loaded from. On a correctly working PERQ, putting a disk in the floppy drive and pressing the reset button will at least load the initial microcode from the floppy. Holding down shift-A will get the rest of POS to load from the floppy too. Yes, that does work on a T2. Nwo, I seem to rememebr that a T2 has to have a hard disk that will go ready -- that is assert the READY/ signal on the control connector, before it'll try to boot from floppy. The drive doesn't need to contain any valid data, it doesn't even need to be formatted. I think a T1 will boot from floppy even if the hard disk is totally dead. One thing worreis me a lot about what you've told me, or rather what you've not said. You assume that the boot track is corrupted, with AFAIK no real evidence for this. You will find I don't take kindly to people who make random assumptions, and nor for that matter do PERQs. Also, you don't know if the Z80 system is working. If it isn't, the machine cna't boot from floppy, since the FDC is connected to the Z80 I/O procesor. So for that matter is the SIO that takes in data from the keyboard, so if the Z80 system is malfunctioning, it'll not read the keyboard either. There are several things I would do. Firstly, I'd check signals at the hard disk conntectors (standard ST412 inteface in a T2). Is said drive going ready? Then, if you have, or can borrow, a logic analyser, ask me for the boot listhing. Connect said analyser to the mcirocode address lines (on the lowermost test connector at the front of the CPU board). We can then see if it's trying to boot from floppy, if it's trying to boot from the hard disk, or what. I think that's right. The drive is selected all the time (unless you have a second drive installed), so the LED is on. Actually, the drive is squirint out the bitstream of the current track, but the machine might well be ignoring it :-) It seems to me an more a hardware failure of the hard drive (as opposed to a corruption/checksum error) One question. IIRC you told me this is a Micropolis 1300-series drive. Those are notorious for a decayed rubbre bumper inside the HDA which means the heads don't load, the drive doesn't find track 0, and then fualts. IIRC, the drvie spins down when this happens. Do you know if your drive keeps on spinning? -tony