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driver/media/A2091RAMPatch.lha

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Showing:m68k-amigaosppc-amigaosppc-morphosi386-arosi386-amithlonppc-warpupppc-powerupgeneric
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Short:Move A590/A2091 driver from ROM to RAM
Author:patrik.bo at gmail.com (Patrik Axelsson)
Uploader:patrik bo gmail com (Patrik Axelsson)
Type:driver/media
Version:1.0
Architecture:m68k-amigaos
Date:2015-05-10
Download:http://aminet.net/driver/media/A2091RAMPatch.lha - View contents
Readme:http://aminet.net/driver/media/A2091RAMPatch.readme
Downloads:516
This is a patch for the A590/A2091 ROMs which changes from the default behaviour
of executing the driver code directly from the ROMs, to executing it from RAM.

If you have an accelerator, this patch makes the execution of the driver code
faster as it will end up in cacheable FastRAM, which also translates into a bit
higher transfer rates. On a plain 68000 machine, it shouldn't give any advantage
unless waitstates are required when accessing the ROMs, but I don't know as I
haven't tested. It will also use use 12904 Bytes more RAM than the regular
version.

This patch is very simple. It just changes two things at a total of four bytes.
First it changes two bytes with the size of how much of the ROM that
expansion.library should copy to RAM. It will now copy the entire used part of
the ROM instead of just the DiagArea, initialization code and ROMTAG. Secondly
it patches an instruction in the initialization code so it will use the copy
of the ROM now residing in RAM as base address instead of the address to the
onboard ROMs.

The result is more or less like a permanent version of util/boot/A2091ToFast.

The patch is distributed as two IPS files - one for each ROM. It is based on the
V7.0 ROMs with sha1sum dbd7648e79c753337ff3e4f491de224bf05e6bb6 for the U13/even
ROM and 149f5bd52e2d29904e3de483b9ad772448e9278e for the U12/odd ROM.

Thanks to SpeedGeek for making me understand that the A2091 executes its driver
code directly from ROM.


Contents of driver/media/A2091RAMPatch.lha
PERMISSION  UID  GID    PACKED    SIZE  RATIO METHOD CRC     STAMP     NAME
---------- ----------- ------- ------- ------ ---------- ------------ ----------
[unknown]                   20      20 100.0% -lh0- 1c74 May 10 14:44 A2091RAMPatch.even_U13.ips
[unknown]                   20      20 100.0% -lh0- f2d8 May 10 14:44 A2091RAMPatch.odd_U12.ips
[unknown]                  905    1686  53.7% -lh5- 9070 May 10 22:39 A2091RAMPatch.readme
---------- ----------- ------- ------- ------ ---------- ------------ ----------
 Total         3 files     945    1726  54.8%            May 10 19:05

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