Neptune-X DIY project

[eidis]

 Hi Guys !

There is a homebrew ethernet adapter for X68000 called Neptune-X. It was invented by Shi-MAD and is realised by using an X68000 project board with attached ISA slot which is populated by a donor NE2000 compatible LAN card with Realtek RTL8019AS chip on it.

Neptune-X by Shi-MAD
http://nfggames.com/X68000/Schematics/Neptune-X/Shi-MAD/

Later this design was simplified by Applause where he replaced most of the IC's with Xilix XC95144 but still kept the Realtek RTL8019AS chip

Applause Neptune-X
http://nfggames.com/X68000/Schematics/Neptune-X/Applause/

Last time the project board was seen on Yahoo auctions for sale by a seller called matukuni95
http://nfggames.com/X68000/Schematics/Neptune-X/Shi-MAD/Pic/project_board_1.jpg
http://openuser.auctions.yahoo.co.jp/jp/user/matukuni95

So a very good question arises. Would it be possible to simplify it even more and update the design with more modern and more easily available and cheaper components.

Please let me know your thoughts and suggestions. I would really like to see this project come through.

Keep the scene alive !
Eidis

Update: There are sellers on eBay who offer PCB design and manufacturing. One of them is "Sky Electronic" http://stores.ebay.com/skyelectronicmart

[BlueBMW]

I have designed a few PCBs and had them manufactured.  If I had a solid schematic and parts list, I could probably get them made.  Though PCBs are expensive in small quantities.  And these would be quite large compared to the ones I've made in the past.

[eidis]

  Here's the plan. Let's try to draw a PCB layout of the Shi-MAD's version first. That way we will understand the Applause's version much easier. IMHO it would be better to replace the Xilix XC95144 with simpler logic chips which do not require a programmer. I don't know if that is possible but we will find out eventually if we dig deep enough.

Which program do you use for PCB layout design ? I have very small experience with Lattice ispLEVER classic.

Keep the scene alive !
Eidis

[BlueBMW]

I've been using the program from this company: http://www.pad2pad.com/

You can price / order directly from the design software.  I'm sure there's better out there, but it seems adequate for most things.

Here's what I had made in the past.  I think for 250 of them it cost around $200 or so.  But these are quite small.

[eidis]

  Today I found another archeological gem. Believe it or not, here are the full schematics and part list for Neptune-X in a easy to understand way:

Neptune-X Schematics by Sha
http://nfggames.com/X68000/Schematics/Neptune-X/Sha/Neptune-X_Schematics.png

Part List
http://nfggames.com/X68000/Schematics/Neptune-X/Sha/PartList.pdf

The original schematics were drawn in EasyDraw which is an X68000 SX Window application. If someone is interested in original file, I made a SASI bootable image with SX Window and EasyDraw. The schematic is called neptunex.drx and is in EasyDraw directory.

SX Window with EasyDraw and schematic
http://nfggames.com/X68000/Schematics/Neptune-X/Sha/X68000/NeptuneX_Schematics_EasyDraw_SX_Window.zip

Keep the scene alive !
Eidis

Update: The Realtek RTL8019AS chips can be purchased separately on eBay and are dirt cheap.

1x New Realtek RTL8019AS QFP100 IC Chip
http://www.ebay.com/itm/1x-New-Realtek-RTL8019AS-QFP100-IC-Chip-/400273487140?pt=LH_DefaultDomain_0&hash=item5d3228b524

[eidis]

 Hi Guys !

Lydux gave me valuable advice regarding this project and hereby with his permission I give you some interesting details. Here's what he had to say:

Basically, this design is 90% the same as ERSA ! But instead of the IDE connector, you have an RTL8019AS and next the RJ45 plug/magnetics. The CPLD code (XC95144 vs EPM7128) would mostly be the same.

ERSA was designed with the open electronic suite called "gEDA" on linux (http://www.geda-project.org/). It includes various tools, here I use "gschem" for drawing the schematics, then a script called "gsch2pcb" that produce the necessary files for routing the pcb. This helps a lot in controlling that all traces are present and correctly wired. Then the program "pcb" for drawing. Gerber comes later, when you want final production. I rarelly use them because of stages of prototyping, I produce my pcb myself.

Ok so, as all what you have found are all prototypes, incompletes or old projects, you should go with a full schematics redrawing. Something that will more look like to the Applause one.
What I could advice you first is to get a good CAD soft. (gEDA, Eagle, ... You should try some first).

What you can do now is getting ERSA schematics, remove the IDE parts and wire an RTL8019AS in place of.
For a reminder : a CPLD is a brainless reprogrammable component. You do whatever you want with all marked "I/O" pins. So in case of routing problems, you can just swap I/O wires. The programmation is done in a HDL family languages (most known are Verilog, VHDL, ABEL) and flashing the CPLD is done on board, via the JTAG inferface (available as well in ERSA). So here in my home, ERSA card is pluged in my Compact, and a simple JTAG programmer hooked between my PC parallel port and ERSA. The X68K is powered on when flashing have to be done.

For the RTL8019AS side, take a look at this picture:

http://nfggames.com/X68000/Schematics/Neptune-X/Applause/Pic/RTL8019AS.jpg

You will have to use the exact same pins as this one. Those following have to be hooked to the CPLD :
- Address lines : SA0 => SA4 (equivalent to IDE_A0 => IDE_A2 in ERSA, plus 2 more lines)
- Data lines : SD0 => SD15 (equivalent to IDE_D0 => IDE_D15 in ERSA)
- Interrupt : INT0 (equivalent to IDE_IRQ)
- Hardware reset line : RSTDRV (you can get rid of the 74HC04, the RESET inversion will be done by the CPLD)
- Address enable strobe : AEN (equivalent to IDE_CS0)
- Read strobe : IORB (equivalent to IDE_RD)
- Write strobe : IOWB (equivalent to IDE_WR)

On bottom-right side is the lan plug connected to RTL8019AS pins TPN+, TPN-, TPOUT+ and TPOUT-. 20F001N is the magnetic, CON8 is the RJ45 plug. You can replace these 2 components and the 2 LEDS by a more recent all in one solution like an "HR911105A" from HanRun (widelly available on ebay at cheap price).

Passive components and power lines are all the same.

Keep the scene alive !
Eidis

P.S. ERSA schematics can be found here:
http://nfggames.com/X68000/Schematics/ERSA%20Project/Schematics.pdf