Designing Amiga Expansion Hardware

[bubba]

I've been doing software for years now and want to try my hand at designing and building some hardware for my Amiga for fun.  Specifically, I'd like to look at building an simple A1200 expansion card with a Motoroloa CPU or a GFX chip.

I am pretty familiar with hardware level programming, but have very little experience with microelectronics except for a couple of electronics courses in engineering school of which I have no memory.  So, I think I could handle the software side of whatever I create.

Anyway, is it realistic to expect me to gain the needed expertise to design and assemble and something like this in one or two years?  Where should I start?  I'm sure there is some great software that I can use for design and simulation.

I think it would be great if the community could get togeter and create DIY desigs for some cool amiga hardware, or at least create designs/prototypes that could be use as a basis for a real production run.  For example, I'd love to have a 24-bit scan doubler/flicker fixer design right now.

All advice is welcome.

-Bubba

[srg86]

I'd start with something a lot smaller than a 32-bit CPU card. Maybe a small ram card or something.

srg

[JimS]

Look at this site... www.pad2pad.com. Once you do the design, you can use their software to layout the board and do the traces. Then you can have them build it for you. Sounds cool, someone just pointed me there yesterday. I've always wanted to try doing a PCI buss adapter to hang off the side of the GVP processor card in my 2000. Just for fun :-) Or maybe a recreation of the Zorro to ISA adaptor from way back..

[dawiper]

I would love to see a external/interal scandoubler/flickerfixer for the A1200. One that works out of the box and can handle ALL modes.

[billt]

Look up

http://www.csee.umbc.edu/~plusquel/650/
http://geda.seul.org/
and
http://www.opencores.org/

for ideas and electronics design considerations. opencores probably has information about free or cheap CAD/EDA tools and design flows. I'm planning to buy a copy of Eagle PCB from www.cadsoft.de as it is the most affordable and has better feature support than the GPL PCB software. I know I cannot afford protel or orcad or their like, which are more than US$10000 per license. (Yes, more than ten thousand dollars) Eagle isn't quite as fancy as those are, but seems pretty decent, and they have a free eval version and even cheaper hobbyist licenses fro simpler designs than the full-blown pro version. Some other vendors have free licenses for old versions or time/feature-limited evaluations. I've been encouraged to look up Cadstar Express and P.R.Editor for some of this.

[melott]

@Bubba

I think an in-expensive card that would allow A2000
users to use the ISA slots on the Amiga side would
be great.

 

[B00tDisk]

melott wrote:
@Bubba

I think an in-expensive card that would allow A2000
users to use the ISA slots on the Amiga side would
be great.

 

Or for that matter, an acellerator card that has either a mini-PCI or full PCI connector (on a ribbon or cable) on it.

Really give those old 2000's something to sing about!

[Stedy]

Bubba,

My advice is to start small and work your way up. I have made the mistake of trying to do too much and not succeeding. Keep it simple and you will succeed.

Designing a processor card with PCI, RAM interfaces and the like is no small task. How long it will take you the necessary skills to design a system is up to you but most of all you should enjoy it.

There is plenty of free and low cost software available but you will need to understand electronics first. I second the use of Eagle CAD, it is great for schematics and PCBs.

For simulations, the student edition of PSpice or LTSpice is good for Analogue/High speed. For Programmable logic, Altera, Lattice and Xilinx offer good free software.

I have a near complete design for a scandoubler, admittedly only 16 bit colour though but only uses 4 ICs. Probably a bit complex but if anyone wants the details, I'll upload them to my website.

Ian

[patrik]

@Stedy:

I would definately be interested in the details and I'm pretty sure I'm not the only one :=).


/Patrik

[billt]

I have a near complete design for a scandoubler, admittedly only 16 bit colour though but only uses 4 ICs. Probably a bit complex but if anyone wants the details, I'll upload them to my website.

If you're not interested in scaling your design to 24bit, I'm sure someone around here would like to try. I'd love an internal flickerfixer for my A1200...

[Martin_Lee]

sounds like fun!

id also say start small. ram card or something

[Stedy]

Patrik, Billt,

I need to tidy things up first before putting the design online. The S-video/composite interface is done but the Video ADC for the RGB inputs needs to be done and the 31 KHz bypass.

The core part is the Averlogic AL250, this only accepts RGB565 video input (16 bits of colour). The design is all surface mount and the PCB design will be complex as it is nearly all analgoue circuitry.

Give me a few days and I will put the details online.

Ian

[JimS]

A couple years ago I looked around the net for some info on interfacing the 680x0 to the PCI bus. I did find an application note for a circut that used 2 chips. One was the companiy's product, the other a generic PLD with some glue logic defined into it. Even had the equations for the PLD in the note. My notion was to hang this off the back of the GVP card in my 2000.
Doing the ISA bus would be easier. There was a card on the market that did it... I think they just mapped the ISA expansion space into part of the Zorro II memory space.

[Effy]

Just want to add that there are also belgian people interested in those clever designs, even if they are "only" 16 bit which still looks megacool compared to 8 bit !!!!!!!

[bigdan]

For designing yours PCBs, you could also try the excellent Amipcb program made by Roland Florac, a french electronic teacher ! Only problem, amipcb is localized but not yet the big amigaguide ;-(

Available on aminet/misc/sci : http://www.aminet.net/package.php?package=misc/sci/AmiPCB_1.07.lha