anne007@star.cs.vu.nl.UUCP (07/12/88)
Hai, Has anyone experience connecting a SCSI harddisk to the atari? Does it need a lot of extra hardware. Where can I find schematics? Pointers please via e-mail : anne007@cs.vu.nl Thanks in advance Q: Is there any Risc in cutting the nr of instructions down to one? A: NOP!
niels@dutesta.UUCP (Arjen Baart) (07/15/88)
Anne Steegstra writes: >Has anyone experience connecting a SCSI harddisk to the atari? >Does it need a lot of extra hardware. Where can I find schematics? Since I'm not too satisfied with Atari's 20MB harddisk (small, slow and pretty expensive), I'm considering to connect a 30 or 40 MB harddisk to my 520 ST+ (either SCSI or ST506). My questions are similar: Where can I find specifications of SCSI and/or ST506 and what software/hard- ware modifications are needed on the Atari to make it work ? Thanks in advance.
braner@batcomputer.tn.cornell.edu (braner) (07/17/88)
[] Here is what I think I know about connecting hard disks to the ST. Anybody with more definite data please comment! One can get an adaptor card that turns the Atari DMA port into a SCSI port (or a sufficient subset of SCSI?), from several sources, including Berkeley Micro Systems and Atari themselves (as a replacement part for the Atari HD system?). The latter is cheaper ($50 ?) but the BMS (> $100) comes with helpful instructions. Besides the adaptor card you'll need a cable to connect to the ST. The Atari card has a 19-pin D-type connector right on it, you'll need a shielded cable that is rather short (18 inches?). The card also needs 5V supply. That done, you can directly connect a standard SCSI drive. The Atari card fits a 50-pin (?) edge connector. If your SCSI drive is in a box with external type connectors you'll need an adaptor, otherwise a flat ribbon cable is fine. The flat cable in the Atari drive is about 8 inches long. The smallest package can be achieved by buying a spanking new 3.5" drive that has SCSI built right into it. The Seagate drives with an 'N' suffix are like that. Search "Computer Shopper" and other mags for a good deal. You'll also need a box and power supply (5V and 12V, about 2 amps each). These small drives don't need a fan. Make air holes in the box. A cheaper setup can be made by buying a SCSI<-->ST506 controller (about $90 in the mags, slightly more from BMS). (You can also get fancy adaptors that can control moe than one drive, tape drives, etc.) You can also get a SCSI<-->RLL controller, if you want to plug in an RLL drive (e.g., the 30 Meg Seagate ST238). If you get the standard kind, make sure you don't get an RLL drive. Standard drives include the Seagate ST212 (10 megs, real cheap), ST225 (20 megs, $200), ST251 (40 megs, $350, much faster than the ST225), etc. Get a half-height drive for smaller space and power requirements. All the drives above are 1/2 hgt. Many other brands exist, Seagate has a good reputation. You can also choose a 3.5" drive with the standard (non-SCSI) interface. They sport high speed (~30 millisecs), low power, and automatic head parking. But one of those plus the SCSI controller cost, together, more than a drive with built-in SCSI. Supposedly, all the standard drives have identical connectors. You should look for ready-made cables. Once you have the hardware connected, you need software. Supra has a nice set of programs for using, booting, examining, etc. They sell it separately from their drives, for $25. (Where ?) There are others. Hope this helps. - Moshe Braner ME? I bought an Atari SH204 on sale ($500), it lasted 7 months and then the drive mech died for no apparent reason. I'm still undecided on how to fix it, and wish I went homebrew right from the start.
ge@hobbit.sci.kun.nl (Ge' Weijers) (07/25/88)
From article <1179@dutesta.UUCP>, by niels@dutesta.UUCP (Arjen Baart): > > Anne Steegstra writes: > >>Has anyone experience connecting a SCSI harddisk to the atari? >>Does it need a lot of extra hardware. Where can I find schematics? > > Since I'm not too satisfied with Atari's 20MB harddisk (small, slow and > pretty expensive), I'm considering to connect a 30 or 40 MB harddisk > to my 520 ST+ (either SCSI or ST506). My questions are similar: In the German magazine C'T a simple circuitboard (<= $25 cost, incl. IC's) was shown which allowed using any ST506 disk with an OMTI5520 controller for XT's. Driver software was published too. Disadvantage: no booting from the harddisk. This must be one of the cheapest ways of adding a harddisk to your ST. I can give more specific info if someone is interested. Warning: the article is in German. (They did the same thing for the Amiga too). -- Ge' Weijers, Informatics dept., Nijmegen University, the Netherlands UUCP: {uunet!,}mcvax!kunivv1!hobbit!ge
hase@netmbx.UUCP (Hartmut Semken) (07/29/88)
In article <300@hobbit.sci.kun.nl> ge@hobbit.sci.kun.nl (Ge' Weijers) writes: >From article <1179@dutesta.UUCP>, by niels@dutesta.UUCP (Arjen Baart): >In the German magazine C'T a simple circuitboard (<= $25 cost, incl. IC's) >was shown which allowed using any ST506 disk with an OMTI5520 controller for >XT's. Driver software was published too. >Disadvantage: no booting from the harddisk. And the HD-Port is not useble for other devices (tapes or the like). They just provide the signals the OMTI wants by software. They do not use the adressing sheme and protocol Atari defined for the HD-Port. So it is not compatible with *any* software that does adress the HD directly (not via system calls). It is bootable by now (with a ROM patch). hase -- Hartmut Semken, Lupsteiner Weg 67, 1000 Berlin 37 hase@netmbx.UUCP High on a rocky promontory sat an Electric Monk on a bored horse. (D. Adams)