DEC VS2000 and SCSI, was Re: DEC RD54 from Maxtor

John Allain writes: . Since I haven't seen any other responses, I'll dive in... This is all speculation - I'd love to have someone with a line into DEC Engineering answer this properly. To put it another way, I may be completely off my rocker - reader beware! ;^) The VAXstation/MicroVAX 2000 was released in 1985 (cf. R.D. Davis' uVAX FAQ), which means development and planning may have started as early as 1983 - I'm just guessing here. In the early 80s large (> 20MB) ST-506 hard drives were still hugely expensive beasts. If you did find a native SCSI device, I imagine the costs would be much higher for the extra interface logic on the drive. Without native SCSI on the device, you needed a translator like the Adaptec ACB-4000 (SCSI/ST-506) or Emulex MT-02 (SCSI/QIC-02). The base VS2000 was a pretty small box - perhaps even ground- breaking for this timeframe, given it could run full 32-bit uVMS or Ultrix and had internal storage, unlike the Sun-2/50. Having to develop and wedge in a unique converter board may have been riskier than adapting a version of a board you were already producing/ designing for the other uVAX models like the RQDX3. Going back to that comparison to the Sun-2/50 may answer the question of why SCSI was acceptable for the tape interface. Since the tape drive was going to be external, there's plenty of room for that extra logic board. And it's only a tape drive, so if we can't get decent throughput out of our first (?) SCSI interface, well, who's going to notice when the tape drive is as slow as the TK50? ;^) After a few years of Apple, Sun, and others driving SCSI into the marketplace the whole picture changed and by the time the first pizza box workstations come out everything is SCSI. Anyway, that's my best shot at an explanation. Again, I'd love to hear from someone who was inside DEC (Megan?)... --Steve.