Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watnot!watmath!clyde!rutgers!ames!amdahl!kim From: kim@amdahl.UUCP Newsgroups: comp.sys.amiga Subject: Comments on future ASDG products (HD controller and 2000-and-1) Message-ID: <6049@amdahl.UUCP> Date: Sun, 29-Mar-87 06:13:19 EST Article-I.D.: amdahl.6049 Posted: Sun Mar 29 06:13:19 1987 Date-Received: Sun, 29-Mar-87 23:36:26 EST Organization: Amdahl Corporation, Sunnyvale, CA 94086 Lines: 130 Keywords: disk caching ASDG 2000-and-1 slots hard disk controller pre-fetch [ For all you do ... this line's for you ... ] Continuing with the technical information gleaned from ASDG's March NewsLetter, along with some comments of my own ... The SDP/SDPI hard disk controller features: o Peak transfer rate close to 2 Mb/sec to/from the Amiga, with sustained transfer of 400 Kb/sec from a SCSI drive, and 400 Kb/sec from an ST506 drive simultaneously. o Subjective performance should be faster than ASDG's RRD (on writes), but not quite as fast as ram:, due to ... o 1/2 Meg of on-board local ram, which lives in I/O address space, not the Amiga CPU's address space, and it's own ... o On-board 68000 (or 68010) 8 MHz processor, which together are used to provide ... o Smart disk caching, which sorts (orders) the requests for blocks from hard disk in such a way that the hard disks heads need only make one pass across the disk instead of back-and-forth, back-and-forth. If I read the newsletter correctly, the disk caching algorithms will also provide for pre-fetching of blocks before they are actually requested. [ I hope ASDG will provide enough information and "hooks" to allow users to install their own pre-fetch/replacement/ordering algorithms, or otherwise tune and optimize the system based on individual requirements. E.g., for some applications, an LRU (Least Recently Used) replacement algorithm might provide superior performance, while in another user's environment, first-in-first-replaced might be better, etc. Then there are questions like store-thru vs. non-store thru, but I digress ... any comments, Perry? ] o The controlling "firmware" for the above will be downloaded at boot time, to allow for changes in the file system format, bug fixes, etc. o The "base" versions will allow up to 8 SCSI devices to be attached to the controller [isn't that really 7, one being the controller itself?] An extended version (the SDP/ST and SDPI/ST) will also support two ST506 devices. o Available with and without drives. As with the 020 board I described in my previous posting, this sounds like a dynamite controller. I suppose it's asking for alot, but it would be even more impressive if it used the new RLL encoding schemes used by people like Perstore and Adaptek in the PClone world. (RLL increases the effective storage available on a given ST506 type drive by 50 to 90 percent. I dunno if it works on SCSI drives, or not). The 2000-and-1 expansion box for the A1000: This has been described on the net before, but to reiterate, it will provide 5 A2000 slots (or Zorro II, as ASDG calls them), 4 PC/AT slots, and 2 Zorro I (A1000) slots. The A2000 and PC/AT slots are "layed out in the same manner as on the A2000", which I guess means they "overlap" by two slots thusly: | | | | | | | | <---- PC/AT slots | | | | | | | | | | | | <---- A2000 slots | | | | | There is no mention of an unbuffered CPU slot like the A2000 has (though I suppose one of the Zorro I slots would work for some applications), nor of a seprate Video slot (naturally). It will also have space in it for two hard disk drives, and a power supply that will be able to "power a fully loaded 2000-and-1". It will *not* be painted black (hot pink, Perry?!) Now for some personal criticism of this box (as well as the A2000 itself). There aren't enough slots! If we assume I add a Bridge card, I can have either 3 PC/AT slots and 3 A2000 slots left over, or 2 PC/AT slots and 4 A2000's. Now lesee, on the A2000 side, I will add more memory, a HD controller, and an 020 board. That leaves me only ONE measly slot for all those nifty things that will be forthcoming (TWO in an A2000, if I use CBM's 020 board in the CPU slot). Where will I be able to find room for addiitional parallel and/or serial ports, *and* a frame-grabber/buffer, *and* a real-time digitizer, *and* an Ethernet board, *and* who knows what else next month? Sigh. At least the A2000 *seems* to have left the door open for additional expansion (did you notice a "knock-out" connector cover behind the CPU slot in the Byte pictures?) On the PC/AT bus, it looks worse, since there are most likely only two slots available, but at least (if this bus is *truly* up to PC/AT specs) you can add on an external PC expansion box in 6, 8, and 12 slot sizes from I-Bus Systems, or others! BTW, if you're thinking of putting a hard-card in one of the PClone slots, be advised that *most* hard-cards take up two slots due to their width (though I have seen at least one that only requires a single slot). So anyway, CAN WE PLEASE HAVE MORE SLOTS, PLEEEEEESE!!! Slots, like ram, like disk space will always get filled, and 4 just aren't enough for all of the exciting products that the Amiga is capable of supporting. Not nearly! And will ASDG and/or CBM and/or another h/w vendor PLEASE get busy and design an expansion box for the A2000 itself? It will be needed sooner than you think! Does anyone else feel this way, or am I alone in my quest for slots? Hmmmmm ... this posting is almost as long as my last one. Time to cut it off. BTW, this ASDG NewsLetter that I've refered to was prepared on an A2000 using Gold Disk's PageSetter program. Nice job, guys! There's alot more info on the products (without *too* much hype), ASDG's history, new Warranty policy, etc. /kim P.S. I'm *still* not associated with ASDG (except as a registered RRD user), nor do I have anything to do with I-Bus Systems, nor Perstore, nor Adaptek ... -- UUCP: kim@amdahl.amdahl.com or: {sun,decwrl,hplabs,pyramid,ihnp4,seismo,oliveb,cbosgd}!amdahl!kim DDD: 408-746-8462 USPS: Amdahl Corp. M/S 249, 1250 E. Arques Av, Sunnyvale, CA 94086 CIS: 76535,25 [ Any thoughts or opinions which may or may not have been expressed ] [ herein are my own. They are not necessarily those of my employer. ]