Phoenix Motherboard Project

[hese]

Here is a project I've been working on lately. It's a Phoenix motherboard, an Amiga 1000 motherboard replacement, developed by Phoenix Microtechnologies in 1990. This board is from the 2005 reproduction batch where people bought the bare PCB and assembled the motherboard themselves.

The board is now nearly assembled, only a few components are still missing such as the programmable GAL chips, some connectors, sockets and smaller bits and bobs.





I'll add another mega of ram to the board and probably also the SCSI chip.

After that the jumper boot camp begins. Quickly counting there's over 70 jumpers on the board to be set.

 

[mfilos]

What an awesome board. Thanks for the mornin' pr0n man!
Can't wait to see it in action

 

[BlindGerMan]

Congratulations for that board! I have a working Phoenix here, with Turbo Board, Graphics card, IDE and USB...
a wonderful piece of hardware! But the jumpers are a bit tricky!

 

[BloodyCactus]

really nice! Is this a modified version like the GBA release or a rerun of the original phoenix schematic? did anyone ever make the memory board for the 96pin expansion?

 

[hese]

Thank you for the comments, fellows.

As far as I have understood the 2005 version had some minor changes compared to the original Phoenix motherboard. Maybe someone with more knowledge about this would enlighten us? BlindGerMan?

Was the original 96pin memory expansion ever released? I've only seen a prototype of it.

 

[Matt3o]

this is gorgeous!

 

[McTrinsic]

You may want to consider the SCSI-Hack for pseudo-DMA...

 

[hese]

Apparently the differences between remade and original motherboard remains a mystery till I resolve it myself. No problem, I can do it.

In the meantime, the rest of the components have now been put in place and the chips programmed.
Next the jumpers need to be figured out and then test the motherboard for the first time.

 

[McTrinsic]

There is no mystery as there is no difference.

The newer boards are exactly that, newer.

Cheers,
McTrinsic

 

[McTrinsic]

By the way, the jumpers are described in the appendix of the manual. As a start, the pic on Amiga.resource.cx should tell the jumpers, the manual is available there as well. The pic is from me and might just be adapted for ChipRAM and Z-II configuration, which is described in the manual.

Cheers,
McT

 

[hese]

Thanks. I took a first plunge on the jumpers and got a green screen. The motherboard was jumpered to use Obese Agnus (1 MB) with 512kB Chip and 512kB Fast RAM. The U60 chip was removed and jumpered so that it was not in use.

Apparently you have a newer Agnus installed on your board. You have 512kB of memory onboard without U60 installed? I'm trying to figure out why I'm getting green screen.

 

[McTrinsic]

I have 2 MB Chip with the ObeseAgnus.

ChipRAM-config is well described in the manual, see also the Appendix.

Are you sure you use right KickROM-config??

Cheers,
McT

 

[hese]

Success, it finally boots!


The problem was with the KickROM settings, I had one jumper too many which caused the green screen. Green screen seems to be a generic error for Phoenix, it appears even without Kickstart. Apparently the U70 chip has to be removed and L117 jumpers set if there is no Zorro card on the B2000 expansion slot, otherwise you get white screen. Too bad the chip can't be left there and circumvent it with jumpers.

The memory jumpers were well explained in the manual but the rest of the jumpers not so well or at all. I had to resort to the schematics and third party documents to find out what the other jumpers do.

By the way, there is vertical banding seen on the screen. Don't know if it's because of the scandoubler or the motherboard itself. Also the screen flickers when floppy drive is accessed. Are these known problems with Phoenix motherboards?

 

[McTrinsic]

I have an older board and can not confirm these issues.

For detailed discussion you might want to try the international section of a1k.org.

The hardware-gurus there might be able to help you, my knowledge stops here.

I can only highly recommend an Indivision ECS - it's a great addition that's worth it.

Cheers,
McT

 

[hese]

Thanks but I'm certain all the gurus have seen the thread and will participate when they have a hunch. :wink:

In the meantime I populated the board with another megabyte of RAM, a U60 chip and configured the board to use it as 1MB Chip + 1MB pseudo Fast.
Seems to be working fine.

 

[Atreus]

It's very nice to see such a nice board in action.
Congrats

 

[hese]

Had a bit of spare time to concentrate on this project. The motherboard was still lacking the SCSI add-on and that unfairness just needed to be corrected. The SCSI support was added by installing the 5380 SCSI chip and SCSI Boot ROM. The U27 SCSI PLD chip was already installed before.

An old SCSI drive was plugged to test the SCSI feature. 134kB/s... not quite fast.


The speed could be increased with a small hack. There is a pseudo-DMA SCSI hack available for the motherboard which involves cutting one track and soldering a few jumper wires. Also the U27 chip needs to be reprogrammed with a new code.


With the pseudo-DMA hack the speed increased to 404kB/s, about 3x faster than before. Nice improvement. The speed was benchmarked using the on-board 68000 7.14MHz CPU.


What speeds other Phoenix users have achieved?

 

[McTrinsic]

Phoenix Motherboard Project

Approximately 1MB/s with the hardware-hack.
68030 @ 50Mhz