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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: SpeedGeek on March 26, 2011, 10:45:20 PM

Title: A2091 14Mhz SCSI mod
Post by: SpeedGeek on March 26, 2011, 10:45:20 PM
Here is a link to this mod:

http://eab.abime.net/showthread.php?p=745151
Title: Re: A2091 14Mhz SCSI mod
Post by: magnetic on March 27, 2011, 12:04:33 AM
really cool thanks for the link
Title: Re: A2091 14Mhz SCSI mod
Post by: desantii on March 28, 2011, 03:24:17 PM
Did thsi last night, my transfer rates went from 1.4 to 2.7 mb/s
 
awesome
Title: Re: A2091 14Mhz SCSI mod
Post by: ognix on March 28, 2011, 04:48:17 PM
Great stuff! :D
Hope to did it on A590 as well! (since they're almost the same)
Title: Re: A2091 14Mhz SCSI mod
Post by: fishy_fiz on March 28, 2011, 05:02:39 PM
Is that card based on the adaptec a2091 scsi controller? I used to use a pci based one with my a1200/grex some time ago and got much, much faster transfer rates than quoted there (about 7.7meg iirc).
Title: Re: A2091 14Mhz SCSI mod
Post by: Zac67 on March 28, 2011, 05:23:02 PM
Adaptec A2091??? Could it be you mean an AHA2940? Does up to 10 MB/s. Got a few in a drawer...
Title: Re: A2091 14Mhz SCSI mod
Post by: SpeedGeek on December 25, 2012, 06:46:42 PM
** NEWS UPDATE **

A new 33C93A_14MHz util was uploaded to the Amibay thread. Unfortunately, you need Amibay membership to download files. Non-Amibay members send me a PM with your email address if interested.
Title: Re: A2091 14Mhz SCSI mod
Post by: mechy on December 25, 2012, 08:39:28 PM
Quote from: SpeedGeek;720304
** NEWS UPDATE **

A new 33C93A_14MHz util was uploaded to the Amibay thread. Unfortunately, you need Amibay membership to download files. Non-Amibay members send me a PM with your email address if interested.


why not upload it to aminet?
Title: Re: A2091 14Mhz SCSI mod
Post by: SpeedGeek on December 26, 2012, 02:58:59 PM
Quote from: mechy;720310
why not upload it to aminet?

Well, that's a long story. Aminet is a good place for software archives but not such a good place for hardware hacks and mod projects. I made the decision more than a year ago (for better and worse) to consolidate all of my projects on Amibay's Photo Booth forum. It's much easier to have a central site to maintain and update everything.

At the time it seemed the best place for them and they were well received.
I didn't realize that membership was required to download files and that Amibay's stricter site rules and stronger moderation style could be a problem for some. (But it's possible to get banned on any site if you break the rules).
Title: Re: A2091 14Mhz SCSI mod
Post by: Ral-Clan on December 26, 2012, 04:16:01 PM
This is great.  I wish I had seen this years ago when I was doing intensive audio work with my A2000 and couldn't get enough speed out of my A2091.  Of course, I was having problems with the transfers to DMA RAM on my 68040 expansion board as well (the kind that vbak2091 can help with), so I'm not sure if your hack would remedy that.
Title: Re: A2091 14Mhz SCSI mod
Post by: SpeedGeek on December 26, 2012, 11:46:52 PM
Quote from: ral-clan;720363
This is great.  I wish I had seen this years ago when I was doing intensive audio work with my A2000 and couldn't get enough speed out of my A2091.  Of course, I was having problems with the transfers to DMA RAM on my 68040 expansion board as well (the kind that vbak2091 can help with), so I'm not sure if your hack would remedy that.

The 040 compatibility problem is solved by upgrading to C= V7 ROMs or a Guru ROM. As far as getting more speed with this hack you will get more speed in an A2000 or possibly a Zorro BusBoard for small box Amiga's. But in the A3000 or A4000 you won't get more speed due to Super Busters bus arbitration and slower Zorro2 slave cycle bottlenecks. Super Buster is a DOWNGRADE for Zorro2 cards!
Title: Re: A2091 14Mhz SCSI mod
Post by: Ral-Clan on December 27, 2012, 03:10:41 PM
Quote from: SpeedGeek;720406
The 040 compatibility problem is solved by upgrading to C= V7 ROMs or a Guru ROM. As far as getting more speed with this hack you will get more speed in an A2000 or possibly a Zorro BusBoard for small box Amiga's. But in the A3000 or A4000 you won't get more speed due to Super Busters bus arbitration and slower Zorro2 slave cycle bottlenecks. Super Buster is a DOWNGRADE for Zorro2 cards!


Well, I had both a 7.0 ROM and later a GURU ROM and never got great speeds.  But maybe I was doing something wrong.
Title: Re: A2091 14Mhz SCSI mod
Post by: Matt_H on December 27, 2012, 08:49:37 PM
Quote from: SpeedGeek;720360
Well, that's a long story. Aminet is a good place for software archives but not such a good place for hardware hacks and mod projects. I made the decision more than a year ago (for better and worse) to consolidate all of my projects on Amibay's Photo Booth forum. It's much easier to have a central site to maintain and update everything.

At the time it seemed the best place for them and they were well received.
I didn't realize that membership was required to download files and that Amibay's stricter site rules and stronger moderation style could be a problem for some. (But it's possible to get banned on any site if you break the rules).

Are you familiar with the docs/hard directory (http://aminet.net/docs/hard) on Aminet? Perfect place for this. I think Aminet is a much safer place for long-term archival storage than a web forum.
Title: Re: A2091 14Mhz SCSI mod
Post by: SpeedGeek on December 28, 2012, 03:29:09 PM
Quote from: Matt_H;720475
Are you familiar with the docs/hard directory (http://aminet.net/docs/hard) on Aminet? Perfect place for this. I think Aminet is a much safer place for long-term archival storage than a web forum.

If someone wants to upload the archive to Aminet that's OK with me but I won't be responsible for updates there. The latest updates will be on Amibay unless it becomes necessary to move my mod projects elsewhere.

P.S. It's already been updated to V.95!
Title: Re: A2091 14Mhz SCSI mod
Post by: ChaosLord on December 28, 2012, 03:36:24 PM
@SpeedGeek

You could just upload your stuff to Aminet like once every 5 years as a backup.

That way if some calamity befell you and you ended up dead or married or something or if Amibay dies or gets hacked then there will be a backup on Aminet.

Websites get hacked and destroyed all the time.
Title: Re: A2091 14Mhz SCSI mod
Post by: SpeedGeek on June 05, 2013, 12:08:25 AM
** 2ND NEWS UPDATE **

I patched 4 bytes of code in the ODD ROM (U12)* and  now I can boot with 33C93A  registers set for 14MHz! The 33C93A_14MHz Util is NO longer needed for C= V7.0 ROMs (but still  useful for testing patched ROMs).

*NOTE: The even numbered ROM actually refers to the odd byte!

The ROM binary won't be posted here for the same reason it's not posted on Amibay so it will be posted on EAB. ;)

http://eab.abime.net/892490-post4.html