Subject: RE: broken KA690?
To: 'Lord Isildur' <mrfusion@umbar.vaxpower.org>
From: Carlini, Antonio <Antonio.Carlini@riverstonenet.com>
List: port-vax
Date: 07/16/2001 14:37:05
> Lord Isildur wrote:
	>On Sun, 15 Jul 2001, Hugh Graham wrote:
	>> Your machine's not broken. I've not got a reference for which
	>> instructions are available on which cpu families, but I've never
seen
	>> EMODD work natively on NVAX.  The confusion stems probably from
so
	>> much old code assuming these instructions will be present.

	>doh!!! it's one of the only D_float instructions not supported!!! 

	Think about ACB{F,D,G,H}, EMOD{}, POLY{}
	These will give you reserved instruction faults
	on some processors.

	Add to these MATCHC, MOVTC, MOVTUC, CRC, EDITPC
	These will give you instruction-emulation exceptions
	on some processors.


	>(yes i have a TM sitting right here.. i had even looked through the

	>supported instructions lists and yet posted under the influence 
	>of, reading the VARM which declares that, among 
	>others, the instructions for each floating format "Each of these
data 
	>types may only be subset as an entity. This means that if one of
these 
	>data types is included, all the instructions that operate on that
data 
	>type must be included." (cp. 11, sec 2) so, the NVAX violates the
VARM!! 

	It somewhat disagrees with 1987 VARM (EY-3459E-DP).
	That, however, is not the VAX Architecture. You need 
	DEC STD 032. Specifically, section 11.1.3, which discusses
	the above mentioned Emulated-Only Instruction Group.

	"No VAX processor announced after 1986 is required
	to implement ...".

	>*isildur grumbles and the strange ways of the DEC gods* 

	The gods had more recent parchments laid before them ...

	I assume that the VARM just never made it through 
	another production cycle.

	Given that VAX is now *two* architectures old,
	you might try asking to see if COMPAQ would
	release DEC STD 032 as electronic text. Ask
	soon, before they lose it ...:-)

	You might try for VAXBI, UNIBUS and QBUS
	specs while you are at it. I guess XMI is too
	recent ....


	Antonio