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From: scott@memex.UUCP (Scott Williamson)
Newsgroups: mod.computers.vax
Subject: Unix applications -> VMS
Message-ID: <8610031115.AA25586@doc.memex.uucp>
Date: Fri, 3-Oct-86 07:15:41 EDT
Article-I.D.: doc.8610031115.AA25586
Posted: Fri Oct  3 07:15:41 1986
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This is a request for information on various aspects involved in
porting an application from Unix to VMS. (NB. The Unix involved here
is not on a VAX)

We have a device which could be made to look like 8 registers in the
Unibus address space and would want to feed data from disk to the
device as fast as possible. Currently, using a fairly complex Unix
device driver we manage to easily keep up with the disk read time (0.8
- 0.9 Mbytes/sec) and believe we could handle up to 5 Mbytes/sec in
the near future.  Would it be straight-forward to write a VMS
device driver for this? Is it necessary? (ie. Could the device
registers be accessed directly from a user program?) What about
performance? The ideal solution would be to be able to initiate (from
a user program?) some sort of DMA from disk to a single destination
register.

What about Qbus? How different is a Unibus driver from a Qbus driver?

Some details on experiences in porting large applications written in C
to VAX/VMS would also be helpful. Is Decshell of use in the conversion 
process since we make use of some Unix utilities? Does Version 2 give 
anything other than 'vi' and a Unix-like 'cc'. Any experiences with 
other Unix-like interfaces? Is there a 'make' for VMS or some conversion 
from Makefiles to MMS.

Replies by mail would be appreciated.

Scott Williamson
UUCP: ..!seismo!mcvax!ukc!memex!scott