Boot Problem on 4000T Cyberstorm PPC Scsi Bus

[danbeaver]

I'm afraid changing the mask and the size of the transfer really doesn't matter; I won't cite references but I did an extensive search recently and found this to be an "old wives tale.". The CSPPC SCSI (cybppc.device) is a 68-pin UWSCSI bus supporting 15 devices with up to 8 logical units and one controller defaulted to #7; unlike the Blizzard SCSI device that HAS internal termination, the CSPPC needs two (2) "Active, Wide, LVD/SE powered terminators."  These correct for signal irregularities at UW speeds. Without them you are prone to hobgoblin of bus errors -- odd, irregular, unpredictable errors. On top of that, the SCSI controller does not play nice with a bunch of hard drives. It also does not like having U160 and U320 HDDs on the same bus.

The bus should look like:  TERM---CSPPC---Drive---Drive---TERM.

Look on EBay or the Internet for "female, active, wide, LVD or SE 68-pin terminators."  They run about 5 to 10 US, not 40 to 60 US.

The truth is out there, just search for it (and take notes).

[danbeaver]

We were talking about hard disk drives

[danbeaver]

That said, you guys missing something! I did not see one mention of what is highly important device driver settings: MaxTransfer and Mask! These, though they are technical, MUST be set up correctly as per the instructions!! Otherwise you can expect missing drives, crashes and gerneal unstability!  Ergo, you cannot pull a HD from your A4091 and stick it on your CyberSCSI, without adjusting the settings and at least setting MaxTransfer to the smallest safest value supported by both controllers.

From http://www.amiga-stuff.com/text/filesystems/SFS158.guide

"The MaxTransfer field"
The MaxTransfer field can be used to tell a filesystem that the device which comes with your (harddisk) controller can't handle more than a specific amount of data in a single access.  This problem usually occurs with IDE drives, which usually have a limit of 64 or 128 kB which can be transfered at once.  When a device has been properly written it should be able to cope with any amount of data being transfered.  These devices can have a MaxTransfer value of 0x7FFFFFFF.  Only badly written or very old devices need to set a smaller value in MaxTransfer -- in other words, the MaxTransfer value is a compatibility kludge to fix broken devices.  In any case, if you have a SCSI drive, then a MaxTransfer value of 0x7FFFFFFF should be just fine.  For IDE drives, you probably need to set it to 0x1FFFE or to 0xFFFE.  Those values represent 128 kB minus 2 bytes and 64 kB minus 2 bytes respectively.  An incorrect MaxTransfer value can usually be detected by copying a few large files (more than 200 kB) to such a partition.  If the large files are damaged while smaller files are undamaged then this is usually an indication that the MaxTransfer value is too large."

"The Mask field"  The Mask field can be used to tell a filesystem that the device which comes with your (harddisk) controller cannot directly access its data in all regions of memory available on your system.  When a device has been properly written it should be able to cope with data located anywhere in memory.  For those devices the Mask should be set to 0xFFFFFFFF.  Only badly written or very old devices need a different Mask -- in other words, the Mask value is a compatibility kludge to fix broken devices.  For example, some devices can't access data starting at an uneven address in memory.  Some even can only access data when it starts at an address which can be divided by four.  In the first case you would set the Mask field to end in 'FFFE', and in the second case to 'FFFC'. If your controller can handle addresses without alignment restrictions then you can set it to 'FFFF' (which is of course the preferred value).  There are also devices which can only access memory in the 24-bit memory area (everything below the 16 MB boundary).  Usually these are Zorro-II controllers which cannot directly access memory located on, for example, an accelerator card.  For these devices you set the mask to 0x00FFFFFF, indicating that the device can only access data in the 24-bit address space.  Devices which can access data located anywhere in memory (a SCSI controller which is embedded on an accelerator card, or a Zorro-III IDE or SCSI controller) should have a mask of 0xFFFFFFFF."