mwm@eris.BERKELEY.EDU (Mike (My watch has windows) Meyer) (05/04/87)
In article <3424@jade.BERKELEY.EDU> spencer@eris.BERKELEY.EDU (Randy Spencer) writes: >used in Mike's Xebec. It is also on the Microbotics hard disk (this That's Mike's ex-Xebec... The tale follows... I took one home. Plugged it into the Amiga without the memory expansion. Worked like a charm, if I booted off of their disk. After wading around some, I figured out what was going on to boot, at least enough that I didn't mind re-arranging things some. At this stage, it became obvious that the documentation was inadequate. It says "you can either autoconfig the drive, or make it work out of your startup-sequence." No words on how to do either. By examing their startup-sequence, I figured out what should happen. Step two. Plug my memory expansion back in, then plug in the Xebec controller. It no boot. In fact, it doesn't even do the "tweak every device to let it know we're here" stuff. Fiddle with the thing some, and finally convince it to boot. Gee, the neat little program "scsimount" that you run to read in the parms file off of SCSI: doesn't run. Stare at the wall, reboot a couple of times and try it again. Run GrabMem to turn off fast memory, then run it. Aha! It works. That Xebec would provide something _that_ important that doesn't work with expansion memory does _not_ bode well for the future. The system runs for a couple of hours, with little or no problem. Suddenly, it starts crashing. Regularly. Usually a 68000 trap in high memory. Give it up, unplug the Xebec, and go back to my stock system to work. A call the next day to Xebec produces "huh? We've never seen that before." They also weren't aware that scsimount wouldn't run out of fast memory. A call to RS Data (the people who built my memory expansion) produces: "You should get the C-Ltd system. The new one works like a charm with our hardware, and is _fast_." Also, "Well, it sounds like a power-supply problem. Do <hack/hack/hack> to our board, and it might fix it." The Xebec drive system has gone back to the store. I got full credit towards a C-Ltd system, again with the understanding that it _will_ be made to work. >The full SCSI spec supports buss arbitration and disconnect/reconnect. >This allows you to hook up more than one host to more than one drive. >This is actually what I am interested in doing. Apparently, the new C-Ltd system can do some of that. From dealing with SCSI on Suns, there are two things people tend not to do that needs to be done to make things go fast. One is disconnect/reconnect. The other is asynch I/O. The former gives you better throughput in multi-drive or multi-system environments. The latter gives you better throughput in any system (factor of 2!). <mike -- Take a magic carpet to the olden days Mike Meyer To a mythical land where everybody lays ucbvax!mwm Around in the clouds in a happy daze mwm@berkeley.edu In Kizmiaz ... Kizmiaz mwm@ucbjade.BITNET
ins_adjb@jhunix.UUCP (Daniel Jay Barrett) (05/09/87)
In article <3447@jade.BERKELEY.EDU> mwm@eris.BERKELEY.EDU (Mike (My watch has windows) Meyer) writes: >[RS Data says] "You should get the C-Ltd system. The new one >works like a charm with our hardware, and is _fast_." > >Apparently, the new C-Ltd system can do some of that.... "New" C-Ltd system?? What is it? How does it differ from the hard disk that they've been selling previously?
mwm@eris.BERKELEY.EDU (Mike (My watch has windows) Meyer) (05/11/87)
In article <4843@jhunix.UUCP> ins_adjb@jhunix.UUCP (Daniel Jay Barrett) writes: <In article <3447@jade.BERKELEY.EDU> mwm@eris.BERKELEY.EDU (Mike (My watch has windows) Meyer) writes: <>[RS Data says] "You should get the C-Ltd system. The new one <>works like a charm with our hardware, and is _fast_." < < "New" C-Ltd system?? What is it? How does it differ from <the hard disk that they've been selling previously? As I reported, I dragged the Xebec back to the dealer (plug: Winners Circle Systems in Berkeley), who's giving me full credit for it towards the C-Ltd system. I told him about the new drives, so he called and checked. Yes, C-Ltd is selling something newer than what he had in stock. Other than the previously mentioned extra speed & more SCSI features, it's supposed to have been repackaged into something that looks nice. The old drives the dealer had were in packaging that looked like the kind of things we would throw togethor for one-shot field test. Just bend the metal into the right shape, spray it, and don't worry about sealing all the edges, or even if they didn't quite meet each other. There were gaps along the edges of the controller card & the disk drive card; both of which were Amiga-tan sheet metal. I'm still waiting for C-Ltd to get the new drives to me, so I don't know how they look. Could someone who's gotten a C-Ltd drive recently (Tom?) comment on that? <mike -- Take a magic carpet to the olden days Mike Meyer To a mythical land where everybody lays ucbvax!mwm Around in the clouds in a happy daze mwm@berkeley.edu In Kizmiaz ... Kizmiaz mwm@ucbjade.BITNET