AMIGA & PC SCSI-Network ----------------------- Report about experiences by ICEHAWK. Translated from German into English by Oliver Brunner. (V1.0 on 16.08.1995) SCSI-Net -------- Many have got an Amiga and an PC-compatible at home, which they want to connect via SCSI. On the Amiga SCSI is nearly standard. Many have already thought of connecting an Amiga with a PC via SCSI. You can .. The advantage is clear, you don't have to buy two CD-ROMS etc., because the two Computers can share one. Only the Amiga is possible to access the Harddisks of the PC to exchange files. The other way is not possible, because of a lack of an Amiga- Filesystem for the PC. I [ICEHAWK] have connected an Amiga 3000 with internal SCSI-Controller and a 1GByte harddisk to a PC with Adaptec SCSI-Controller and a 200MByte harddisk via SCSI. Both Compters are connected with a 50pin SCSI-cable. IMPORTANT ! READ THIS! This description should be only for people, who don't have two left hands and know how to solder. You should have Hardware and SCSI-experience. We [ICEHAWK and the translator Oliver Brunner] will not overtake ANY liability for upcoming problems and damages! All you do is at your own risk, all given data without warranty, Hardware Requirements --------------------- You need for a SCSI-Network: Hardware: - Amiga with SCSI-Harddisk and external SCSI-Connector - PC with SCSI-Harddisk and external SCSI-Connector - SCSI-cabel with 50pin Centronics or 25pin SUB-D The SCSI-Id of the Controllers should be changeable and the TERM-POWER (+5V) should be able to be switched off. Software: - Amiga: CrossDOS Standard System 2.x (better CrossDos V5.0!) - PC : A small program, wich rereads in the directory-information. Diskchange for the PC: Diskchange causes an update of the PC-Filesystem. This is needed, if a SCSI-Network is built up. Dos interuupt 21 clears all diskbuffers, so that afterwards a new read-in of the actual directory is done. Synopsis: DISKCHGE How to build up the network: ---------------------------- 1. First of all the TERM-POWER (5V for the SCSI-Bus) must only come from ONE Controller). ATTENTION: MULTIPLE SUPPLYING OF TERMPOWER CAN CAUSE HARDWARE DAMAGE! ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Amiga 3000: You should dig out the manuals for your A3000 and search for the diode (*) D800, which is the SCSI-protection diode. I [ICEHWAK] have simply cut the diode on one side from the motherboard and soldered a fuse between D800 and the motherboard. [* I don't know the English expression for 'Diode', think it is diode :). If not it is something like that: | /| --|< |-- in ASCII :)] | \| Before: DIODE D800 --------- o----| | |------------------------o --------- After: DIODE D800 1Amp fuse --------- ---------- o----| | |---------|--------|-----o --------- ---------- WARNING: LOSS OF WARRANTY! You are not able to switch off the TERM POWER at the Adaptec :(. 2. Terminationg-resistors may be only at the beginning and the end of the SCSI-bus. (At my config at the both harddisks). On both SCSI-controllers the resistors are removed. 3. Parity check should be disabled at all connected devices. 4. Every SCSI-unit must have its own SCSI-Id. Amiga: Controller should stay 7, HD id 1. PC : The PC SCSI-controller gets nuber 6, the harddisk 0, because the PC cannot boot from any other Id. Simple example: Amiga 3000 and PC via SCSI: 50pin SCSI-cabel --------------------------------------------- | | |25pin SUB-D |50pin Centronics | | |-----------------------------| |-------------------------------| | Internal SCSI-Controller | | Adaptec SCSI-Controller | | |TERM-POWER (+5V) OFF!!! | | |TERM-POWER (+5V) ON! | | |NO RESISTORS ! | | |NO RESISTORS! | | | | | | | | | Harddisk | | | Harddisk | | |------------| | | |------------| | | | | | | | | | | | UNIT 1 | | | | UNIT 0 | | | | WITH | | | | WITH | | | | RESISTORS | | | | RESISTORS | | | | | | | | | | | |------------| | | |------------| | | | | | |-----------------------------| |-------------------------------| Amiga3000 PC Software: --------- The PC needs only the program "DISKCHGE.EXE", which causes a reread of the actual directory. At the Amiga diskchange (c:) does this job. HINT: The harddisk of the Amiga should be not accessable from the PC side, because the PC does not support Amiga Filesystems. You can avoid errors like accidently formattig your HD from the PC side this way. On the Amiga you will need 'MOUNT' and a mountlist for your PC-HD. INSTALLATION: ------------- PC: Copy "DISKCHGE.EXE" somewhere in your PATH. Amiga: Create a Mountlist for the PC-Harddisk. Easiest way to do so, is to use CROSSDOS V5.0 and choose at installation time the option "Install an 100% MS-DOS Harddrive". The Software will create a mountlist for you. My [ICEHAWK] mountlist looks like: (CROSSDOS) /* MountFile Entry for full MS-DOS Disk. Disk Size: 199 Meg Vendor and drive name: 000 Unknown 199 Meg */ Surfaces = 1 BlocksPerTrack = 1 LowCyl = 0 /* First Cylinder of HD*/ HighCyl = 408573 /* Last Cyl. */ DosType = 0x4d534800 BufMemType = 0 Device = "scsi.device" /* Change for different Controller */ Unit = 0 /* SCSI-ID of Harddisk */ Flags = 0 FileSystem = L:CrossDOSFileSystem Mask = 0x00fffffe MaxTransfer = 0x00ffffff BlockSize = 512 StackSize = 2000 Priority = 5 GlobVec = -1 Buffers = 5 Activate = 1 After this you can connect the two computers with a 50pin SCSI-cable (switch them off, before doing so, please). Before switching on again, CHECK EVERYTHING AGAIN! BE AWARE OF MULTIPLY SUPPLYING TERM-POWER! Now both machines should boot up normally. If not switch off immediately and go to the beginning of this text. Switching on only one machinemay may cause an error, because TERM power is missing. To avoid errors like: "DEVICE xxxx has an READ/WRITE ERROR ON xxxx" on Amiga side, switch on the PC, too, because the bus is not correctly terminated and the TERM-POWER is missing otherwise. Using only the machine wich supplies the term-power may work. WARING! Both machines MUST NOT access the same device at the same time! On your Amiga the Harddisk should be accessable via the device PCC:. You can share CD Roms or Syquest drives now on both sides. Have fun with exchanging your data.. Questions, problems etc: Contact the author of the original German textfile at: The Blackhole Tel:0049 +30/6262281 ByteChannel Tel:0049 +30/8122442 DumpingGround Tel:0049 +30/4327188 MoonBase Tel:0049 +30/6613791 Mail to USER "ICEHAWK" signed THE REAL ICEHAWK 2100 <> Translated to English for Phil Kernick by Oliver Brunner. This translation was done without the permission of the author, because I don't want to have a call from Munich to some mailboxes in Berlin at this damned high German telefon fees. Feel free to send imrovements and comments to me, maybe I will add them... Feel free to upload this file to aminet or whereever you want to. Feel free to report me any wrong spellings in this text, English is not my native language, sorry:).