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- Path: comma.rhein.de!serpens!not-for-mail
- From: mlelstv@serpens.rhein.de (Michael van Elst)
- Newsgroups: comp.sys.amiga.hardware
- Subject: Re: * A3000 Internal Chips - What's the Newest? *
- Date: 8 Mar 1996 11:06:46 +0100
- Organization: dis-
- Message-ID: <4hp0rm$cbb@serpens.rhein.de>
- References: <4hgoik$nd5@carbon.cudenver.edu> <4hlrsd$fc9@cloner2.ix.netcom.com> <2111.6641T64T1527@metrolink.net>
- NNTP-Posting-Host: serpens.rhein.de
-
- Greenl@metrolink.net (Greenl) writes:
-
- >The Ramsey -04 chip can be replaced with the -07, and the Super DMAC -02
- >with the -04. This fixes two problems:
-
- >1. Heat sensitivity. Many 3000's will not work for more than a few
- >minutes with an accelerator card installed, especially with several cards
- >added to the expansion.
-
- Replace "Many" with "Some". Early versions of the DMAC-02 were heat sensitive.
-
- >The rise in temperature of the Ramsey, which sits
- >under the accelerator, causes the timing between the chips to move outside
- >operating tolerances.
-
- It is the DMAC that was heat sensitive.
-
- >2. Speed with static column ram. Not known generally, but the old Ramsey
- >capability to work faster with SC ram was broken.
-
- Partially. The support for burst cycles does work fine. The support for
- page-detect was broken. However, this mode is just turned on erroneously by
- Kickstart2.04 running on 68040.
-
- >Also, setpatch turns
- >this feature off.
-
- It basically turns it on. That is, it doesn't enable or disable it directly.
- It just enables the 68030s burst mode which then utilizes the static column
- support in Ramsey.
-
- >So a lot of people who took pains to buy only SC ram
- >were wasting their time.
-
- With SC RAM and a CPU that supports bursts (i.e. standard 68030 but not the
- A3640 board) you get faster memory access that gives you an additional 20-25%
- speedup.
-
- >To get a speedup in memory speed of about 11-12%:
-
- The memory itself is nearly twice as fast for burst cycles.
-
- Regards,
- --
- Michael van Elst
-
- Internet: mlelstv@serpens.rhein.de
- "A potential Snark may lurk in every tree."
-