A4000 DIY Motherboard - Page 2

pandy71 · 26 February 2018, 11:02

Personally not recommend to use A4000 as reference - IMHO A1200 offer same benefits (Alice + Lisa) and it is way more simpler to design. Going for A4000 as reference mean that you will dedicate lot of resources for Zorro bus where in fact already existing solutions fully replace Zorro functionality at lower implementation cost. I would rather dedicate those effort to place on PCB things normally added to A4000 by additional cards i.e. Ethernet, flickerfixer (or rather scandoubler), audio board etc. I'm working in background on similar project however using ECS - it will be different than normal Amiga architecture as it will provide CPU almost full bandwidth with access to RAM (no penalty for CPU from chipset cycles - CHIP RAM limitations exist only for chipset) and target is to fully replace ECS HW in FPGA.
Good luck with you design.

Mick · 26 February 2018, 11:20

Quote:

Originally Posted by alexh

You say that but as Apollo core evolves *IF* they can get enough HDL developer interest then the entire Amiga chipset will be replaced. The FPGA's they use for Apollo have PCIe Gen 2.1 integrated into them.

I'm not saying he shouldn't modernise or anything it's just that it is presumably much more complicated and it looks like Bebek on Amibay has already attempted something similar and thrown in the towel? all I'm saying is don't jump straight into the deep end. It would be better for the community to have a "standard A4000" in ATX/E-ATX than to have elenachen try to implement all manner of next gen features right from the start and give up due to difficulties.

alexh · 26 February 2018, 11:32

Quote:

Originally Posted by hooverphonique

I don't see that in the store - do I need to contact him directly?

Sorry I meant to type "Amibay"

http://www.amibay.com/search.php?searchid=6818127

alexh · 26 February 2018, 11:38

Out of interest were you inspired by Amy-ITX?

Mathesar · 26 February 2018, 18:58

Quote:

Originally Posted by alexh

Out of interest were you inspired by Amy-ITX?

Amiga can be a harsh mistress. Amy-ITX will whip you in submission to her closed sources.

We could really use an open-source Amiga motherboard using readily available parts.

IanP · 27 February 2018, 02:01

Minimig is very mature now. I see no reason to continue using the original Commodore chips in new motherboards other than to keep interfacing with 5 Volt parts and peripherals simple.

grelbfarlk · 27 February 2018, 03:27

Not to speak for the Ami-ITX folks but from their Q&A they released schematics and I took the answer to mean that they may open the board files and CPLD code someday.

Quote:

Q: Why don’t you release all your stuff for free?

A: This is not as simple as it might sound. Creating good hardware (and software) is both a financial and temporal, not to mention often emotional investment. In true Commodore spirit all Amy-ITX boards is accompanied by detailed printed schematics to aid trouble shooting. So the actual “source” of the design is already released. For now we’re holding on to the digital versions and board schematics though.

Which as long as they do eventually release it then it's fine. For something that took that amount of effort, when they recoup the money for their time investment releasing later is good.

It's not like they can be making some huge amount of money off of the small batches they are doing nor gross profiteering off of selling blank boards and programmed CPLDs.

Rather than the standard in the Amiga community which is "Make some products, get tired of doing it, design is lost forever unless a silly amount of money is offered to "buy" the design."

elenachen · 27 February 2018, 07:52

Sry not interested in FPGA Designing Custom Chips. Plan for now is to build the A4000CR Model as ATX Board and getting it running at all. Will be a shitload of work. Is there a Original Manual with Schematics to this Machine somewhere? Not the remade ones. Maybe there is some additional info in the Originals that could be very usefull.

alexh · 27 February 2018, 07:54

Quote:

Originally Posted by IanP

Minimig is very mature now. I see no reason to continue using the original Commodore chips in new motherboards other than to keep interfacing with 5 Volt parts and peripherals simple.

Minimig was OCS. There has been an attempt to add AGA but it's not as mature a design.

kgc210 · 27 February 2018, 09:43

Quote:

Originally Posted by elenachen

Sry not interested in FPGA Designing Custom Chips. Plan for now is to build the A4000CR Model as ATX Board and getting it running at all. Will be a shitload of work. Is there a Original Manual with Schematics to this Machine somewhere? Not the remade ones. Maybe there is some additional info in the Originals that could be very usefull.

Emufan linked to the Schematics on the third post of this thread.
http://eab.abime.net/showpost.php?p=1222219&postcount=3

pandy71 · 27 February 2018, 10:10

Quote:

Originally Posted by IanP

Minimig is very mature now. I see no reason to continue using the original Commodore chips in new motherboards other than to keep interfacing with 5 Volt parts and peripherals simple.

Minimig is A500 not accurate HW emulator - is more like software emulator translated to HW (GCR in Paula doesn't work as it is not implemented). AFAIK there is only one accurate HW emulator for Amiga http://eab.abime.net/showthread.php?t=59294 .

pandy71 · 27 February 2018, 10:19

Quote:

Originally Posted by elenachen

Plan for now is to build the A4000CR Model as ATX Board and getting it running at all. Will be a shitload of work.

Side to A4000 schematics don't forget about original Commodore specifications for some IC's , i must say sadly that seem for some IC's there is no freely available specification (Super Buster, Ramsey etc) and original schematics may have some errors so it will be good for you to use real, physical A4000 to confront theoretical knowledge with practical implementation. Cost of PCB will be very high (large board with at least 4 layers) so you need be careful before launching your design.

Good luck!

Locutus · 27 February 2018, 10:29

Honestly i would trust the remade schematics more then the original commodore ones.

You will have the advantage of other people already having validated the schematic for you.

grelbfarlk · 27 February 2018, 23:19

Also I second the idea of adding PCI to the motherboard via Prometheus over a fast bus as I've mentioned in other threads repeatedly. SPI and clockport would be nice too.

You could always just leave a socket for Buster and not solder the Zorro slots. I realize the A4000 doesn't boot without Buster but that's probably due to the GALs in that area or the expansion.library or something. I had a machine with a broken buster and it still booted the Logica Diagnostic-so that's my story.

kolla · 28 February 2018, 04:52

Quote:

Originally Posted by alexh

Minimig was OCS. There has been an attempt to add AGA but it's not as mature a design.

Minimig was (is) both OCS and ECS, and the attempt to add AGA works really well. I say that as someone who use it every day on the MiST with both games and applications. There's really just one bug that affects me, but it is only there in lores resolutions.

Chucky · 28 February 2018, 07:28

I love the idea and planned to do the A1200ish as ITX or so.. but too much other stuff.

BUT! A warning: while reverseengineering the A3640, I found that schematics sometimes contains minor issues that is not really true. so do not take the schematics as 100% truth.

elenachen · 28 February 2018, 11:45

I'm currently in the Brainstorming Process, thinking of what to do, what to leave out. I'm thinking about replacing the 200 Pin Local-Bus Connector with something like an PCIe Connector. Something with a Standard behind it, thats available for years to come.

The Idea would be to fit an modded PCB of the 3640 or 3660 inside the new Connector.

A Breakout to the old Connector could be made with a small PCB anyways.

What do you guys think about that?

Chucky · 28 February 2018, 12:10

The 200 pin connector is still made... so I see no reason to change that.

My tip is as first version: change as little as possible.

MigaTech · 28 February 2018, 12:24

This is a good idea, although the work involved is phenomenal !! That A500 board that was released some time back, link below. It was good but expensive and I think they failed to sell in the numbers first predicted. Just added links below in case you haven't yet checked them out.

https://www.generationamiga.com/2016...-kit-released/
http://wiki.icomp.de/wiki/Amiga_reloaded

Not sure if copyright is still an issue, I think if you go commercial with this it might cause a stir in this department?? Unless 25 year copyright cover has elapsed with no renewal?? Although I doubt Amiga incorporated would be bothered to be fair. Other members may know more on this one.

As for modifications on the A4K that Commodore missed out, I think PCI slots instead of the Zorro III would be better. If this could be possible?

elenachen · 28 February 2018, 12:29

Ok, then there will be no problem using that connector after all. I'd like to leave out Connectors like ext. Floppy, Centronics and eventually serial --> Would there be a good reason for leaving the Serial Port in?

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26 February 2018, 11:02	#21
pandy71 Registered User Join Date: Jun 2010 Location: PL? Posts: 2,743	Personally not recommend to use A4000 as reference - IMHO A1200 offer same benefits (Alice + Lisa) and it is way more simpler to design. Going for A4000 as reference mean that you will dedicate lot of resources for Zorro bus where in fact already existing solutions fully replace Zorro functionality at lower implementation cost. I would rather dedicate those effort to place on PCB things normally added to A4000 by additional cards i.e. Ethernet, flickerfixer (or rather scandoubler), audio board etc. I'm working in background on similar project however using ECS - it will be different than normal Amiga architecture as it will provide CPU almost full bandwidth with access to RAM (no penalty for CPU from chipset cycles - CHIP RAM limitations exist only for chipset) and target is to fully replace ECS HW in FPGA. Good luck with you design.

26 February 2018, 11:38	#24
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,337	Out of interest were you inspired by Amy-ITX?

27 February 2018, 02:01	#26
IanP Registered User Join Date: Mar 2015 Location: Bristol/UK Posts: 166	Minimig is very mature now. I see no reason to continue using the original Commodore chips in new motherboards other than to keep interfacing with 5 Volt parts and peripherals simple.

27 February 2018, 07:52	#28
elenachen Registered User Join Date: Feb 2018 Location: Nürnberg Posts: 97	Sry not interested in FPGA Designing Custom Chips. Plan for now is to build the A4000CR Model as ATX Board and getting it running at all. Will be a shitload of work. Is there a Original Manual with Schematics to this Machine somewhere? Not the remade ones. Maybe there is some additional info in the Originals that could be very usefull.

27 February 2018, 10:29	#33
Locutus Registered User Join Date: Jul 2014 Location: Finland Posts: 1,176	Honestly i would trust the remade schematics more then the original commodore ones. You will have the advantage of other people already having validated the schematic for you.

27 February 2018, 23:19	#34
grelbfarlk Registered User Join Date: Dec 2015 Location: USA Posts: 2,902	Also I second the idea of adding PCI to the motherboard via Prometheus over a fast bus as I've mentioned in other threads repeatedly. SPI and clockport would be nice too. You could always just leave a socket for Buster and not solder the Zorro slots. I realize the A4000 doesn't boot without Buster but that's probably due to the GALs in that area or the expansion.library or something. I had a machine with a broken buster and it still booted the Logica Diagnostic-so that's my story.

28 February 2018, 07:28	#36
Chucky Registered User Join Date: Mar 2015 Location: Karlstad / Sweden Age: 52 Posts: 1,210	I love the idea and planned to do the A1200ish as ITX or so.. but too much other stuff. BUT! A warning: while reverseengineering the A3640, I found that schematics sometimes contains minor issues that is not really true. so do not take the schematics as 100% truth.

28 February 2018, 11:45	#37
elenachen Registered User Join Date: Feb 2018 Location: Nürnberg Posts: 97	I'm currently in the Brainstorming Process, thinking of what to do, what to leave out. I'm thinking about replacing the 200 Pin Local-Bus Connector with something like an PCIe Connector. Something with a Standard behind it, thats available for years to come. The Idea would be to fit an modded PCB of the 3640 or 3660 inside the new Connector. A Breakout to the old Connector could be made with a small PCB anyways. What do you guys think about that?

28 February 2018, 12:10	#38
Chucky Registered User Join Date: Mar 2015 Location: Karlstad / Sweden Age: 52 Posts: 1,210	The 200 pin connector is still made... so I see no reason to change that. My tip is as first version: change as little as possible.

28 February 2018, 12:24	#39
MigaTech Only Amiga !! Join Date: Apr 2017 Location: United Kingdom Posts: 588	This is a good idea, although the work involved is phenomenal !! That A500 board that was released some time back, link below. It was good but expensive and I think they failed to sell in the numbers first predicted. Just added links below in case you haven't yet checked them out. https://www.generationamiga.com/2016...-kit-released/ http://wiki.icomp.de/wiki/Amiga_reloaded Not sure if copyright is still an issue, I think if you go commercial with this it might cause a stir in this department?? Unless 25 year copyright cover has elapsed with no renewal?? Although I doubt *Amiga incorporated* would be bothered to be fair. Other members may know more on this one. As for modifications on the A4K that Commodore missed out, I think PCI slots instead of the Zorro III would be better. If this could be possible?

28 February 2018, 12:29	#40
elenachen Registered User Join Date: Feb 2018 Location: Nürnberg Posts: 97	Ok, then there will be no problem using that connector after all. I'd like to leave out Connectors like ext. Floppy, Centronics and eventually serial --> Would there be a good reason for leaving the Serial Port in?

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