25 February 2018, 13:42 | #1 |
Registered User
Join Date: Feb 2018
Location: Nürnberg
Posts: 97
|
ATX4000 - an A4000 DIY Motherboard - Information needed -- pls help out :)
Hi all,
I'm doing my own A4000 Motherboard in an E-ATX format. I always wanted one and these things are terrible expensive. This will be open sourced :-) It would be nice if some of you give me a little help in finding documents or giving tips about the A4000's architecture Schematics --> bugs/errors in them etc. Donations are welcomed too. Things I want to know: Footprint of CPU Slot --> http://www.amigawiki.de/doku.php?id=...s:cpu_cardslot --> Pinout http://www.amigapcb.org/ Distances of CPU Board Holders in relation to CPU Slot? Keylock mechanism obsolete --> 8 Parts cleared out of schematic Which Jumpers are obsolete? : J100 --> CLK90 Source --> needed --> Delay Line will be edited in future Rev. --> need better Oscilloscope, mine only has 20Mhz bandwidth.... J104 --> CPU Clock Source --> needed J151 --> ROM Speed --> probably needed J212 --> Select PAL/NTSC --> needed J213 --> Chipmem Size Select --> doesn't work anyway --> obsolete J214 --> Alice Chipmen 8M --> doesn't work --> obsolete J351 --> Internal Floppy Jumper --> needed J352 --> Redirect DF0: --> probably obsolete --> Will Add Floppy Header for internal Floppy 3-4 J500 --> Sync on Green --> does anyone need this? J501 --> Lisa Sync --> probably needed J502 --> Select DAC Sync --> same as J500 Sync on Green --> anyone needs this? J850 --> Enable DSACK --> there is no 68020 Accelerator for A4000 --> probably obsolete J852 --> Select RAM Size --> needed PS/2 Keyboard and original A4000 Keyboard support --> selectable via Jumpers Port 0 Mouse/Joystick Switcher Zorro Slots --> will be there in classic version. Video Slots --> will be there in classic version. ISA --> will be there in in classic version. Formfactor with Zorro has to be at least E-ATX Future things to be done: 2 Versions of Board --> ATX4000C <--> ATX4000E --- ATX4000C will be classic with zorro and video slots, this is the version as you'll get it first. Later an ATX4000E version will be added. ATX4000C: E-ATX formfactor --> Zorro Slots 5 Zorro Slots 2 Video Slots 5 ISA Slots --> for toaster and bridgeboard people. Maybe a version later with Included 68040/68060 onboard. Will be replacing GAL's with CPLDs in a future version 64MB/112MB Hack possible Maybe support for bigger Roms in the future ATX4000E: Including 68040/68060 onboard Replacing GAL's with CPLDs Scrapping Buster --> Allowing for normal ATX or smaller formfactor Scrapping onboard RAM except Chipram Trying to split the bus, to allow native 68060 Bus speed --> 50/66MHz --> the slower half to Chipset --> faster half to a FPGA for PCI/PCIe and to Fast RAM Adding fast IDE/SATA Some other onboard stuff, if the PCI/PCIe Bridge works Maybe support for bigger Roms So for now: To Do: Transfering Schematics in KiCad and simultaneously creating Bill of Materials --> done To Do: Add Latch for Soft Power on/off --> Done --> Thx @Daedalus To Do: Check if Footprints are Correct --> done To Do: Component Placement on PCB --> in work To Do: Route Prototype To Do: Build Prototype To Do: Probably some minor changes To Do: Release As it's just too much for myself as a first project, I uploaded it on github https://github.com/elenachenchen/A4000-ATX Thank you in Advance Elena Last edited by elenachen; 26 June 2021 at 16:48. |
25 February 2018, 14:03 | #2 |
Registered User
Join Date: Aug 2007
Location: USA
Posts: 360
|
|
25 February 2018, 14:08 | #3 |
Registered User
Join Date: Feb 2012
Location: #DrainTheSwamp
Posts: 4,545
|
hi,
take alook here: Amiga PCB Explorer Amiga PCB Explorer - beta - more Amiga models amigawiki.de - schematics #1) Magic was a bit faster |
25 February 2018, 15:33 | #4 |
Registered User
Join Date: Oct 2016
Location: Norway
Posts: 170
|
Good luck Elena! Seems like a fun project. But are the components needed readily available?
|
25 February 2018, 15:45 | #5 |
Registered User
Join Date: Jan 2004
Location: Yorkshire
Posts: 710
|
I suspect the interest would be massive. I'd certainly love something like that.
I know that the Alice chips are in short supply though. |
25 February 2018, 16:56 | #6 |
-
Join Date: Jul 2003
Location: Helsinki / Finland
Age: 43
Posts: 9,863
|
Very interested. You'll probably have to go eATX to fit full length zorro cards.
|
25 February 2018, 18:00 | #7 |
Registered User
Join Date: Feb 2018
Location: Nürnberg
Posts: 97
|
|
25 February 2018, 18:19 | #8 |
Registered User
Join Date: Jun 2009
Location: Dublin, then Glasgow
Posts: 6,343
|
The hardware reference manual covers the mechanical specifications of Zorro cards here (click the links for the various possible configurations). They're basically the same size as full-length AT cards, but the Zorro connector is at the front of the case, not the rear. Essentially, the motherboard needs to reach around 300mm from the case's back panel in order to accommodate the Zorro connectors.
|
25 February 2018, 18:28 | #9 |
Registered User
Join Date: Feb 2018
Location: Nürnberg
Posts: 97
|
Is there any interrest in using PCIe Cards with a classic Amiga? Or is PCI the highest "usefull" interface? I stumbled over Prometheus. The next step would be to get this to PCIe via PCI to PCIe bridge, but the question would be if cards would be used by the community at all?
So for short: 5 Zorro Slots? 2 Zorro and 3 PCI Slots? Or even 5 Zorro and replace the ISA with the PCI 2 Zorro, 2 PCI and 1 PCIe slot? 2 PCI, 3x PCIe? and so on? What would be viable? I think if i would really do that project, then i would want to go further than just a Standard A4000 in a box. So now, where to start, where to end..... |
25 February 2018, 18:45 | #10 |
Registered User
Join Date: Jun 2016
Location: Stoke-On-Trent, England
Posts: 450
|
One word:
DRIVERS Does not matter what connectors you have, if there are no drivers there is no point. If you are serious on a board see if bebek got anywhere http://www.amibay.com/showthread.php...our-own-Amiga-) If you are really serious adapt the Prometheus directly to the 68060 socket and develop the software so we can interface to something modern other than a VooDoo 3. |
25 February 2018, 19:00 | #11 |
Registered User
Join Date: Jun 2009
Location: Dublin, then Glasgow
Posts: 6,343
|
The only reason for having ISA slots is for use with a PC bridgeboard. Without that requirement, they can be ditched and replaced with PCI. As for PCIe, the only advantage for classics would be availability of cards - PCI already delivers more bandwidth than any classic can use. PCI Radeon cards are available and useable with current drivers in Mediator busboards, and other cards like USB, audio, network etc. are all still easily found in PCI format as well. While PCIe might be doable by patching PCI drivers for the same hardware, it's probably a lot more effort than is currently available in the community. So I would say to stick with PCI.
The Mediator 4000 has both Zorro and PCI slots, which could serve as inspiration. |
25 February 2018, 19:10 | #12 |
Registered User
Join Date: Jan 2004
Location: Yorkshire
Posts: 710
|
A "standard A4000" in ATX format would be extremely popular, you could always redesign it with more modern features later? I'd go with whatever has the widest classic hardware support to start with.
|
25 February 2018, 19:57 | #13 |
Registered User
Join Date: Oct 2016
Location: Norway
Posts: 170
|
Do whatever keeps you interested and motivated enough to finish the project.
People have all sorts of wishes, but it's not up to you to fulfill them. |
25 February 2018, 22:12 | #15 |
Registered User
Join Date: May 2013
Location: Grimstad / Norway
Posts: 839
|
If you're actually doing a new motherboard then I'd suggest dropping the riser card and putting the Z3 slots directly on the board. Erm... you kinda have to do that to fit a pc case? Do Zorro cards fit with pc case slots in width and height and general placement?
|
26 February 2018, 09:25 | #16 |
Thalion Webshrine
Join Date: Jan 2004
Location: Oxford
Posts: 14,354
|
Now is the time to do this. tborro over at Amibay is practically selling the entire A4000 chipset as NOS but he won't have many chips for long.
Last edited by alexh; 26 February 2018 at 11:30. |
26 February 2018, 09:29 | #17 |
Thalion Webshrine
Join Date: Jan 2004
Location: Oxford
Posts: 14,354
|
|
26 February 2018, 09:51 | #18 |
ex. demoscener "Bigmama"
Join Date: Jun 2012
Location: Fyn / Denmark
Posts: 1,624
|
|
26 February 2018, 10:03 | #19 |
Registered User
Join Date: Jul 2014
Location: Finland
Posts: 1,178
|
|
26 February 2018, 10:11 | #20 |
Registered User
Join Date: May 2010
Location: Helsinki, Finland
Posts: 1,341
|
tbtorro is on Amibay, not AmigaKit He has several threads with various chips listed.
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
Thread Tools | |
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
A4000 Motherboard rev F | 1time | support.Hardware | 7 | 31 July 2012 18:09 |
Try repair an a4000 motherboard - help | TTD | support.Hardware | 69 | 13 November 2011 23:03 |
My DIY A4000 tower | Secret Vampire | Hardware pics | 1 | 29 July 2006 17:12 |
[FA] A4000 Motherboard | scan_x | MarketPlace | 6 | 15 March 2004 15:19 |
[FA] A4000 Motherboard | scan_x | MarketPlace | 2 | 12 January 2004 09:58 |
|
|