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Author Topic: A4000 system soon on eBay!  (Read 2785 times)

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Re: A4000 system soon on eBay!
« Reply #29 from previous page: August 01, 2007, 05:43:01 PM »
In the end, it turns out that it is not a question of amount of chip RAM but of speed.

Turns out the reason why there is an 8Mbytes SIMM in there is because there were no 60ns 2Mbytes SIMM in existence. Pretty much all 2Mbytes SIMMs were 80ns or slower.

The official reply from Brian:

About the A4000 chipram. Even though I have an 8 meg module, workbench says that I only have 2mb.  I may have done this to make the 'TurboAGA', my amiga chipset overclocking project, operate at such a high frequency.  It is a 8mb, -6 module.  Commodore's 2mb module was a -8 I believe.

I guess my memory is as small as the amiga's.



And with that the official specs for the machine now are:

-A4000 with 2mb chip ram, 16mb fast ram, Commodore 3640 over-clocked 33MHz 68040.
800mb IDE HD
GVP EGS True Color Retargetable Color System with Video card, 2mb ram, slightly overclocked.
Additional Cybergraphics drivers.

But I can attest to the fact that his 3640 is REALLY overclocked to 33MHz.
 

Offline Crumb

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Re: A4000 system soon on eBay!
« Reply #30 on: August 01, 2007, 06:32:28 PM »
@eslapion

about overclocking custom chips... I know two hardware hackers in Spain who did that. One with his A4000 (He was "bacterio" the guy who used to exchange the GAL/PAL to make IDE go faster, up to 5MB/s. Also the one who made the 64MB hack for A4000) and the second one is a very friend of mine who overclocked his A2000 Denise chip to get 31Khz screenmodes. He says that demos usually hang but that WB worked perfectly. I think he ran some of the custom chips at normal frequency to avoid problems but still wasn't perfect.

about 8MB of chip... it's impossible without new custom chips.
The only spanish amiga news web page/club: Club de Usuarios de Amiga de Zaragoza (CUAZ)
 

Offline countzero

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Re: A4000 system soon on eBay!
« Reply #31 on: August 01, 2007, 06:37:40 PM »
Quote

Crumb wrote:
@eslapion

Also the one who made the 64MB hack for A4000


oops. what's the 64mb hack for the A4000 ?
I believe in mt. Fuji
 

Offline Gaiyan

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Re: A4000 system soon on eBay!
« Reply #32 on: August 01, 2007, 06:43:57 PM »
Quote

countzero wrote:
Quote

Crumb wrote:
@eslapion

Also the one who made the 64MB hack for A4000


oops. what's the 64mb hack for the A4000 ?


You don't know? It's the 64MB chip-ram hack!
 

Offline gdanko

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Re: A4000 system soon on eBay!
« Reply #33 on: August 01, 2007, 07:23:24 PM »
Stupid eBay.
 

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Re: A4000 system soon on eBay!
« Reply #34 on: August 01, 2007, 07:31:53 PM »
An update from Brian concerning the "sex and free beer jumpers.

If you read my second email, 2mb is all the chipram my system has and yes, the jumpers do something.  They allow you to run the system with a 4mb module, NOT 8, in the 2mb chipram module location.  However, you still only get 2mb chipram without any additional fastram.  It's like the extra 2mb never seen or used.  My system will not even run in the 2mb jumper positions unless I can find the original 2mb module which no longer exists.

Cheers.
 

Offline Crumb

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Re: A4000 system soon on eBay!
« Reply #35 on: August 01, 2007, 07:39:22 PM »
LOL, it's 64MB of slow a4000 motherboard "FAST ram" and it's achieved reprogramming some GALs, cuting traces and passing wires. I know an user with that trick. The guy who made that hacks left the amiga scene 6-7 years ago. He worked as technical repair service for cbm and asked David Haynie the sources of various GALs. He reprogrammed the IDE port to make it faster on old A4000 motherboards (I heard newer ones changed from GALs to PALs so the code probably would be useless). I know 2 people with the IDE hack. With a CS MKII 060 the standard IDE transfers around 5MB/s.

Please notice that these hacks involved de-soldering the old GAL and soldering the new one so it was not so easy. He did the hack at some spanish parties. The memory hack was more complex and required that you sent him the motherboard. Unfortunately I doubt I still have his phone number.
The only spanish amiga news web page/club: Club de Usuarios de Amiga de Zaragoza (CUAZ)
 

Offline da9000

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Re: A4000 system soon on eBay!
« Reply #36 on: August 01, 2007, 09:26:49 PM »
Quote

countzero wrote:
oops. what's the 64mb hack for the A4000 ?


It is as Crumb says, and best described by *the man* himself, David Haynie:

http://groups.google.com/group/comp.sys.amiga.hardware/browse_thread/thread/3726897a6bf1e89a/f180904dfc7d79e8?lnk=gst&q=4000+64mb+haynie&rnum=1#f180904dfc7d79e8

It is possible. While on the other hand, the 8MB ChipRAM jumper does nothing:

http://groups.google.com/group/comp.sys.amiga.hardware/browse_thread/thread/ab575681a29073df/ef9edd7721db27c3?lnk=gst&q=david+haynie+sex+and+free+beer&rnum=1#ef9edd7721db27c3


And one last thing: putting 60ns or 70ns RAM in the Chip RAM slot of an A4000 won't make things faster without a hardware hack to speed up the chipset. Supposedly the A4000 to be sold has this, but I wouldn't be so sure without photos and documentation, as it's a hack that is not common (I've personally not seen a reference to it while reading all the Haynie newgroups mails).
 

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Re: A4000 system soon on eBay!
« Reply #37 on: August 02, 2007, 06:20:49 PM »
Here's a reply from Brian Guralnick:

  I personally verified.  When using a single side 4mb SIMM in the chipram module location, moving both jumpers (J213 & J214) to the 8mb position allows you to see 2mb chipram.  All other memory on the module is ignored.

  I was mistaken about the original 8mb quote.  It's been 9 years since I powered the computer up.

  I did this originally to get access to faster ram modules & lower capicitance loads & shorter RAS-CAS cycle time to allow overclocking of the AGA chipset up to an almost double 50 MHz.
 

Offline Flashlab

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Re: A4000 system soon on eBay!
« Reply #38 on: August 02, 2007, 06:25:33 PM »
Quote

 Why is it that somehow I expected stupid comments like that...

Awrite... This machine belong to Brian Guralnick who worked for RCS management. He designed the PCB for the Excalibur accelerator.

If he says there is 8MBytes of chip RAM in this machine then that's because THERE IS 8Mbytes of chip RAM in this machine.

He did specify that most people don't know that the A4000 can support this.

Especially coming from you Mr. TjLaZer... you should know who Brian Guralnick is since you are authorized to distribute the ROMs from another RCS management product.


Priceless! :lol:
Amiga 4000D Cyberstorm PPC 060@50 604@200 SCSI 130Mb Ram G-Rex Voodoo3 PicassoIV Paloma Ariadne Delfina Lite

Online Flash version of BoulderDash: Offline...
 

Offline da9000

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Re: A4000 system soon on eBay!
« Reply #39 on: August 02, 2007, 09:38:55 PM »
Quote

eslapion wrote:
Here's a reply from Brian Guralnick:
I did this originally to get access to faster ram modules & lower capicitance loads & shorter RAS-CAS cycle time to allow overclocking of the AGA chipset up to an almost double 50 MHz.


I'd be curious of the method used to do this overclocking. Anyone have any pointers or sites referencing this?

Also, he said the computer has not been on for 9 years - I think it might be necessary before the sale to check the battery for any leaks...
 

Offline da9000

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Re: A4000 system soon on eBay!
« Reply #40 on: August 02, 2007, 09:53:50 PM »
Quote

Here's a reply from Brian Guralnick:
  I personally verified.  When using a single side 4mb SIMM in the chipram module location, moving both jumpers (J213 & J214) to the 8mb position allows you to see 2mb chipram.


I verified it and it works. Never saw it mentioned anywhere. I wonder if there are any side-effects.
 

Offline Bamiga2002

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Re: A4000 system soon on eBay!
« Reply #41 on: August 02, 2007, 11:48:24 PM »
Is there any chance to get faster ChipRam-access than 80ns on an A1200?
CD32
A500
 

Offline adolescent

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Re: A4000 system soon on eBay!
« Reply #42 on: August 03, 2007, 01:44:34 AM »
What about redrumloa's chipset underclock?  Makes the Z3 fly.  Probably as usable and stable as the hack above, but it's safer.
Time to move on.  Bye Amiga.org.  :(
 

Offline BrianG

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Re: A4000 system soon on eBay!
« Reply #43 on: August 03, 2007, 03:25:19 PM »
Ok, my AGA overclocking was done with a programmable PLL clock.
(Never had a stability issue related to the acceleration itself.)
-------------------------------------------------------
-Bad Effects-
Bad system clock
Floppy drive access useless.
Genlocks disabled it.
Need a multisync monitor, &, 'MonED' to make all the new possible monitor modes.
Audio was also off.
Serial port was also off, however, I made a little utility to fix the baud rate.
requires the change of the chipram module.
MUST HAVE fanned heatsinks on all of the Amiga's chipset chips.

-Great Effects-

60Hz 640x400 was possible in the non-DLB scan aga mode not only freeing up double time CPU to chipram access for those 35ns/pixel modes, now you use the 70ns/pixel, the chipram controler was also almost double speed.  This made the software only version of lightwave layout editor in a 60hz progressive mode run at 4x speed, it scroll smooth like silk with complex scenes.
48Khz audio.
After the serial port patch software, far better 38400 performance.
Parallel port operated at extreme speeds.

PLL design allowed real-time system clock speed changes.
Additional hardware clock line tied to the floppy drive also made it read at almost 2x speed, however, writes were not guaranteed to be good.
----------------------------------------------------------------
Though I can easily make a replacement 'Turbo-AGA' pcb today, there is absolutely no financial incentive to do so, +, if I sell my A4000, I will no longer have a test fixture.
 

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Re: A4000 system soon on eBay!
« Reply #44 on: August 03, 2007, 05:52:18 PM »
Hi there Brian,
Its good to know you created an account here.

I am convinced you can make a very positive contribution here.

I am sure people will want to know all the technical details on how you overclocked the chipset in your A4000 and how you overclocked your 3640 from 25 to 33MHz.

I will be sure to publish all the necessary pictures we took yesterday!