Path: utzoo!attcan!uunet!samsung!zaphod.mps.ohio-state.edu!ncar!boulder!tramp!hunt
From: hunt@boulder.Colorado.EDU (Lee Cameron Hunt)
Newsgroups: comp.sys.amiga.hardware
Subject: A2630 Burst Mode?
Keywords: A2630, Burst Mode, Registers, DRAM
Message-ID: <23779@boulder.Colorado.EDU>
Date: 22 Jul 90 20:42:58 GMT
Sender: news@boulder.Colorado.EDU
Reply-To: hunt@tramp.Colorado.EDU (Lee Cameron Hunt)
Distribution: na
Organization: University of Colorado, Boulder
Lines: 24


This is a trivial question and I believe it was answered a while back when
the A2630 was introduced, but I forgot the answer.

Can the A2630 achieve do burst memory transfers if you fill-out the on-board
memory to 4 Mb?  As I recall, Burst Mode was not enabled on the A2630 because
to do so would require each longword's bits to reside in individual DRAMs
(for a total of 32-one Mb ZIP DRAMs), enabling memory trasfers to proceed
in a column-wise manner.  Shipping the boards with this amount of on-board
memory, at the time, was too expensive.  Is this correct?

It seems that you would have to change a PAL or some such logic to enable
Burst transfers, if in fact the board was max'ed-out to 4 Mb, but perhaps
this is software-selectable through programmable registers.

And while I'm on the subject, can anyone summerize the operations of the
A2630's programmable resisters (I've been told they exist but am clueless
as to what they are for)?

Thanks for entertaining my ramblings...

--Lee
"Nothing is more disorginized than Calvinball!" -- Calvin & Hobbes
hunt@spot.colorado.edu   ...!ncar!boulder!spot!hunt