Re: RAMFast question

[jdb8042@tamsun.tamu.edu (John Donald Baker)]

In article <jd25924@pro-dan>, Dan Brown <vmbb!pro-newton!pro-dan!danb> wrote:
>In <jxj119.59.2E9BFCE5@email.psu.edu>
>jxj119@email.psu.edu (Jason Jeffries) writes:
>
>>SCSI supports seven devices in one chain, and the controller counts as one 
>>of them, so you could, in theory, hook 6 devices up to a RAMFast. On most 
>
>        Close.  SCSI supports up to eight devices in a chain, numbered from 0
>to 7.  Normally, the controller card counts as one, leaving you with up to 7
>devices to hook up.  However, the RamFAST doesn't take up an ID, so you can
>attach up to 8 devices to a RamFAST.

Closer still.  The reason the RF doesn't take up a SCSI ID is that it's
not an initiator.  It's just a host adapter (albeit a really nifty one!).
No simple SCSI or SASI host adapter truly drives the bus, only the drives/
CDROMs/scanners, etc. do that.

Other SCSI cards (like the Apple Rev. C and High-Speed) have a SCSI ID
setting.  This indicates that some external device can select IT, in
addititon to it selecting some external device.  Thus, Apple SCSI boards
could be used as the basis of a SCSI network, since they can be selected
as well as select.  The RF has no SCSI address, so it can't be selected
by an external device, but may only select other devices.

Given this, a full complement of 8 SCSI/SASI devices may be attached to
the RamFAST.

(has this been confusing or what?)


John D. Baker  ->A TransWarp'802'd Apple //e CardZ180 Z-System nut//
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