[fa.info-vax] RANYAN PPL-2 INFORMATION REQUEST

info-vax@ucbvax.ARPA (04/08/85)

From: spracklin@EDWARDS-VAX


	HELP!  I am a DEC software type on Edwards AFB where we use the RANYAN
Peripheral Processor Link (PPL-2) which is a Q-bus/UNIBUS interface to com-
municate between an LSI 11/23 and a VAX 11/780.  The current configuration 
utilizes the LSI hosted memory capability (the physical memory is on the LSI)
which basically performs DMA operations on the LSI side into the memory and
performs Programmed I/O (PIO) on the VAX side.  There is no software required
on the LSI , whereas the VAX software consists of Create Map Section (CRMPSC)
to the UNIBUS addresses controlled by the VAX-RANYAN PIO board.  Communication
consists of memory moves from the UNIBUS address into VAX local memory at an
approximate cost of 10 micro-secs per word.  An effort is aimed at achieving
a VAX hosted memory capability , in particular to develop the software to
support the VAX hosted RANYAN DMA board.  To allow the DMA transfer into
the VAX memory window it is required to set up the UNIBUS mapping registers 
and data path(s) related to the transfer.  The hardware has been checked out
with a logic analyzer and we seem to be talking to the UBA from the RANYAN 
DMA board correctly , yet the two software techniques discussed below have 
yet to transfer a bit. (Excuse the pun?!?)

	1.   CRMPSC/Connect to Interupt approach which sets up the UBA at
	     the initialization entry of CONINTERR.

	2.   A full driver entered via QIO with a timeout of 65355 seconds
	     which should allow transfers until the device interrupts.  Since
	     the RANYAN transfers generally without interrupts this is ideal
	     since we are in a demanding real-time environment.

I have been in contact with the president of RANYAN here in Huntington Beach
and he is unaware of any software to support the VAX host capability.

Does anyone have any experience , knowledge of a site using a VAX hosted 
RANYAN , or any ideas ? Thanks in advance.

Regards,

Darrell Spracklin
(805)-277-3864