On Jul 15, 13:39, David Betz wrote: message. one tomorrow. I've not tried to boot a VAXstation 4000 from CD-ROM, but I've had no problem with lots of other classic machines using older Toshiba drives. Almost all modern (newer than about mid-90s) drives understand the SCSI command to set the blocksize to 512 bytes in software, but older machines don't know to do that. I keep a couple of Toshibas just for that reason; XM3201, XM3301 and XM3401 at least have a couple of pairs of half-moon solder pads, near the SCSI connector, normally linked for 2048-byte blocks, but you can cut the tracks between one or both to set 512-byte blocks. The three different 512-byte settings are supposed to be for Sun, SGI, and Intergraph, but I've never noticed much difference. OTOH, I have a couple of Hitachis and an NEC which can be set to 512-byte blocks, and they don't work too well (the Hitachis in particular are very slow and generate lots of errors), so apparently not all CD-ROM drives are created equal. -- Pete Peter Turnbull Network Manager University of York