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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Doraemon on October 25, 2006, 01:23:46 PM

Title: 64 mb on A4000 mobo
Post by: Doraemon on October 25, 2006, 01:23:46 PM
Hello!
Some time agó someone in spain called "Dr. Bacterius" makes a hardware modification on the amiga 4000 motherboard to accept 64mb of ram.
Now "Dr. Bacterius" its imposible to find.
Anyone knows any document or tutorial describing how I can make this?

Thanks and sorry for my bad english
Title: Re: 64 mb on A4000 mobo
Post by: keropi on October 25, 2006, 01:43:38 PM
if that was true, all would have done that...
Title: Re: 64 mb on A4000 mobo
Post by: ltstanfo on October 25, 2006, 01:46:11 PM
Quote

keropi wrote:
if that was true, all would have done that...


Precisely... that is one of the "holy grails" of AMIGA lore that has never been accomplished.  16MB on the mobo is the limit.

Regards,
Ltstanfo
Title: Re: 64 mb on A4000 mobo
Post by: FrankBrana on October 25, 2006, 02:04:29 PM
Yes, its possible indeed.

I wont share any info. Sorry
Title: Re: 64 mb on A4000 mobo
Post by: LoadWB on October 25, 2006, 02:28:29 PM
Actually, not that it's anyone's business, but I have modified my A4000 desktop to run 64MB on the mobo and 8MB of ChipRAM.  

I chose wisely.
Title: Re: 64 mb on A4000 mobo
Post by: Tahoe on October 25, 2006, 02:33:28 PM
I just did the 8MB ChipRam rework. my SIMM sockets for fast ram are broken; so I just use 128MB on my Cyberstorm.
Title: Re: 64 mb on A4000 mobo
Post by: Ral-Clan on October 25, 2006, 02:38:58 PM
I have hacked my stock Amiga 500 running Workbench 1.2 to interface with a human brain through the clock-port.  Quite easy actually, considering the miracle of the clock port design.  Only takes about $5 in parts from any kitchen supply store and a bottlecap. Unlimited RAM and file storage.

Sorry, but it's a secret so I'm not telling anyone how to make it.  ;-)
Title: Re: 64 mb on A4000 mobo
Post by: LoadWB on October 25, 2006, 02:39:02 PM
That's sweet and all, since you're not using the original Amiga hardware to accomplish this feat, I'm afraid we can't just you as technically running a "Classic" hack.

On a serious note, checking several different search engines resulted in no references to this project or the person.
Title: Re: 64 mb on A4000 mobo
Post by: Crumb on October 25, 2006, 02:43:39 PM
Quote
if that was true, all would have done that...


It's true

He also reprogrammed the IDE GAL chap so it gives 5MB/s with a CSMKII. I know at least two people in Spain with that trick. It only involved reprogramming the GAL chip. It was done cleanly, without overclocking anything. He optimized the code that managed the transfers of the IDE port of the GAL found in old A4000 revisions. He was in contact with David Haynie to do this.

The modifications required for 64MB support were more complex and involved more than reprogramming a chip. You had to sent him the motherboard.

He also overclocked the AGA chips (One of my best friends also does this with his A2000 from time to time so he watches 100Hz/31Khz pseudoPAL screenmodes without scandoubler), the ZorroIII bus, his 3640 board...


Just because you haven't seen it, it doesn't mean it doesn't exist.

Just to clarify: AFAIK the IDE trick could only be done with old board revisions, and the 64MB trick involved more work than changing a single chip like the IDE speedup trick...

@FrankBrana

Gure gasiosie! ;-)  :pint:
Title: Re: 64 mb on A4000 mobo
Post by: snowman040 on October 25, 2006, 02:50:19 PM
I think he used to advertise in c.s.a.hardware...

p.s. Yesterday I found prophet64 forum, seems like Commodore64 users have done much more 'hacking' to C64 then Amiga users to any model :-( Probably due more complex design, but still :-(
Title: Re: 64 mb on A4000 mobo
Post by: TrevorDick on October 25, 2006, 02:54:04 PM
ral-clan wrote:-

Quote
I have hacked my stock Amiga 500 running Workbench 1.2 to interface with a human brain through the clock-port. Quite easy actually, considering the miracle of the clock port design. Only takes about $5 in parts from any kitchen supply store and a bottlecap.

I tried it with my A1200 and a special interface I wired to my left ear. I now too have unlimited Ram (not stictly true as it's limited to the capacity of my brain, which although very large is not quite unlimited) but the trouble is I can no longer get stereo sound out of my amiga, and I've got earache! BTW what type of bottlecap did you use? ;-)

Title: Re: 64 mb on A4000 mobo
Post by: Ral-Clan on October 25, 2006, 03:01:25 PM
Quote
I tried it with my A1200 and a special interface I wired to my left ear. I now too have unlimited Ram (not stictly true as it's limited to the capacity of my brain, which although very large is not quite unlimited) but the trouble is I can no longer get stereo sound out of my amiga, and I've got earache! BTW what type of bottlecap did you use?


I used a bottlecap from a 1973 stubby bottle of "Orange Crush".  I have found this to be the best solution for this hack.  I tried a 1974 cap, but I couldn't access all my screen-modes.  Diet-orange crush bottle caps work but I get occasional GURUs this way.  I think it has something to do with the artificial sweetener residue.

As for your loss of stereo problem.  I have overcome that.  My solution was to use someone else's brain (oops, I wasn't supposed to tell you that).  :-P
Title: Re: 64 mb on A4000 mobo
Post by: keropi on October 25, 2006, 03:07:32 PM
I have to see it to believe 64MB on 4000, and as for overclocked chipset... overclocking??? chipset???
Title: Re: 64 mb on A4000 mobo
Post by: Effy on October 25, 2006, 03:39:46 PM
As for overclocking the A4000 mb, I know that you can underclock it in order to have higher Z3 speed but in return you get a {bleep}ed up sound and video unless you use a gfx card  :-)
Title: Re: 64 mb on A4000 mobo
Post by: redrumloa on October 25, 2006, 03:50:02 PM
Quote

Effy wrote:
As for overclocking the A4000 mb, I know that you can underclock it in order to have higher Z3 speed but in return you get a {bleep}ed up sound and video unless you use a gfx card  :-)


Exactly. Use a sound card and a video card and it's quite good :-)
Title: Re: 64 mb on A4000 mobo
Post by: Doraemon on October 25, 2006, 03:57:16 PM
I've seen a few amiga 4000 with some of that tricks done, but some years ago.
Will be intereasting to have this documented.

Its really true, and the users from spain like Crumb can certificate it.

Thx
Title: Re: 64 mb on A4000 mobo
Post by: Crumb on October 26, 2006, 08:31:53 AM
Quote
I have to see it to believe 64MB on 4000


I was going to sent him my A4000T motherboard but as he only did the trick with desktop ones and I already had a CSMKII fully populated with 128MB I thought... why would I want more ram? Some years later (now for example) I realized it could have been quite useful when you have 2 A4000 and just a CSPPC... :-/ But yes, I know people who has this modification. It involves reprogramming some chips (that maybe A4000T or latest A4000 board revisions don't have) and adding some wires (and maybe cutting others). It's definitely not easy and I seriously doubt you could reproduce the trick without having access to the original sources of the programmable chips.

Quote
and as for overclocked chipset... overclocking??? chipset???


Yeah, my friend has an overclocked ECS chipset that gives him 100Hz/31Khz pseudo PAL screens. :-) He also did a small circuit to reset his agnus chip when he resets his A2000 as CV3D sometimes isn't recognized by P96 (on A2000 with Blizzard 060) when you make a reset. That small circuit fixed that. I really wish he was in contact with "Bacterius" as he could made a few changes in my two A4000... standard motherboard IDE running at 5MB/s... not bad, uh? :-) The downside of the 64MB of RAM in the motherboard is that these are as slow as the 16MB have been always :-/
Title: Re: 64 mb on A4000 mobo
Post by: lopos on October 26, 2006, 10:08:54 AM
Why not make the mod public? Why the big secret? Can someone please explain this to me!
Title: Re: 64 mb on A4000 mobo
Post by: lopos on October 26, 2006, 10:12:51 AM
Sorry! double post
Title: Re: 64 mb on A4000 mobo
Post by: Crumb on October 26, 2006, 03:04:51 PM
@lopos

AFAIK the GAL source code used in various chips in the first A4000s is not property of Bacterius even if he rewrote some critical loops or modified some code to make it accept more memory. So he may get in trouble if he released it.

He made all the modification by himself (you had to sent him your motherboard) and only charged a little (24€ for the IDE hack and 60€ for the 64MB hack). He also made the modifications directly in the parties of the south of Spain. AFAIK he *never* passed the sources to anyone. If somebody has the GAL sources it will probably be Dave Haynie.

It's not impossible to optimize again the A4000 GAL so maybe we could ask Dave Haynie if he could publish the GAL source code of the chip that controls the IDE interface.

We may ask him also about the ram interface. Maybe Bacterius submited back his changes in the source code... but I don't think he would free the code as he's not the real owner. I have doubts about the code not being lost.

BTW last time I heard about Bacterius he was no longer interested in Amiga stuff and he was no longer a technical repair service. I had his phone number in a pile of papers at my parents' house, but I guess it ended up in the trashcan when I went to live alone 3 years ago.
Title: Re: 64 mb on A4000 mobo
Post by: koper on October 26, 2006, 03:11:14 PM
hello guys!

i'm the owner of the a4000 that mr. bacterious make possible to run with 64 mb(4 simms x 16 mb) in motherboard.

if you need some information, i have the way to talk with mr bacterious.

greetings froms catalonia - Spain
Title: Re: 64 mb on A4000 mobo
Post by: lopos on October 26, 2006, 03:30:33 PM
@Crumb
Thanks for the explanation. It's a shame that it isn't open source since A4000 aren't produced anymore.