Denial

I have a project thats borderline to work, but for now only a home project. With that in mind I don't want to spend too much on the PCB layout & simulation software. I was thinking of Proteus but finding a model of the 6502 was more like mining old labs and the only thing that looks usable is to import a multicomponent model (http://www.6502.org/users/dieter/m02/m02.htm) which is not really what I want.

Anyone had any success at finding a good platform with a 6502 included?

I use Diptrace primarily now but used Eagle for about 12 years. Depending on what you are up to, both have free versions which may cover your design.

I don't know if either have the 6502 built into the libraries, but I can create libraries for any parts that you need if you decide to use either one of those.

Aaron

amramsey wrote:I use Diptrace primarily now but used Eagle for about 12 years. Depending on what you are up to, both have free versions which may cover your design.

I don't know if either have the 6502 built into the libraries, but I can create libraries for any parts that you need if you decide to use either one of those.

Aaron

Ok, I'll check it out! I also looked at CircuitLogix which is more integrated with its own internal spice implementation. For now, the best thing I have found is the spice model at http://www.visual6502.org which is probably very accurate, but also very slow.. Importing it into CircuitLogix may be a little cumbersome.

What spice model did you base your 6502 simulation on?

I don't have a good answer for simulation... simulating a cpu in circuit means running code on the cpu which is beyond most simulators for pcbs. So normally just a few thought experiments and then build the pcb and try it out. Boards are only a couple of bucks these days so it doesn't take much to try out some ideas in real hardware.

I use EAGLE:

• It has a free (as in beer, not speech) version that hobbyists can use
• It has auto schematic->PCB annotation, which most other lighter weight tools don't have (I know, it sounds like a hokey feature, but it is invaluable to add a part on the schematic and it shows up right away on the PCB design)
• I have learned to be really good at it. Yes, the UI is not the best, but man I can crank out designs all day long now
• Many hobbyists use it. Look at Make Magazine, etc.
• Lots of libraries. Sparkfun, LadyAda, etc.
• Many open source projects use it so the designs will be easy for others to replicate. Since I exclusively do FLOSS, it seemed appropriate.

I've tried gEDA and KiCAD. Of the two, KiCAD is the best, but no auto annotation, and that interrupts my workflow a LOT.
I've toyed with DesignSpark and other tools, but always come back to EAGLE.

Jim

I use Altium Designer for my projects. Of all the professional packages I have used this is the best. Very good balance between enterprise and flexible.

There are perhaps few that can buy such a package as a hobbyist. So among the more available free or low cost, I would also go with Eagle. Especially since it is almost de facto standard among open hardware etc.

For simulation I use various versions of spice. I only simulate analog circuits. I see little point in simulating digital or MCU circuits. Exception FPGA.

An earlier version of Altium was used to create the Behr-Bonz schematic and PCB layout back in 2008.

Its an excellent software IMHO.

I learned on "Tango" which is probably kindof unknown today back then it was the only package (available for mortals) that had a half working auto router (which was used to teach us to never use the autorouter =P). For personal small things i use eagle, mostly for the reasons brain mentioned. Company uses Altium, but i havent done much with it yet. If i'd start today i'd probably prefer KiCAD, mostly because its really free and thats a very strong point for me when it comes to tools.

I use Fritzing. Free, open-source and pretty easy to use. Targeted at beginners (like me), but lacks a few features and the part library is a bit strange.

http://fritzing.org/home/

I also want to look into Upverter which is a kind of neat spin in that it's online / collaborative with change tracking and so on (kind of a github for hardware projects).

https://upverter.com/

amramsey wrote:I use Diptrace primarily now but used Eagle for about 12 years. Depending on what you are up to, both have free versions which may cover your design.

I don't know if either have the 6502 built into the libraries, but I can create libraries for any parts that you need if you decide to use either one of those.

Aaron

Ok, I settled on Eagle. I have bought some W65C02 and W65C22, both in PLCC-44 package. I also bought some holders with standard 0.1" spaced pins, so it all looks nice. I found a Eagle W65xxx library, but it only contained the DIP-40 package. Do you have libraries with these (e.g. PLCC-44) in them?

I will put those symbols/footprints together in the next few days for you.

amramsey wrote:I will put those symbols/footprints together in the next few days for you.

Oh, great!

I have tried to put together my first layout and I must stay I'm quite green on this, even after years experience with making semiconductors and doing alot of programming. PCB layout just haven't gotten my attention.

Well, I tried to make a 65C02 coprocessor and a scheme to plug it into the Vic-20 expansion port. The basic idea is to share some memory and I added some flip-flop to actually set the "RDY" flag on the 65C02 so that it doesn't run until the 6502 of the Vic-20 tells it to. I also added a 65C22 and I have a feeble idea of paging a 128KB SRAM so that the Vic-20 gets some more memory to play with (e.g. 34K * 2).

Here is my current layout.. version 0.1 pre-alpha (and please ignore IC3 at the moment)

EDIT: version 0.2b pre-alpha... now also with Bluetooth LE and 20+ fixes.. Still need to fix the $400-> writes as the logic only works for the 6502.
EDIT2: version 0.4blue pre-alpha... parts of the circuit are up and running, so I can read/write to the memory chip from the Vic-20. Some bus stability problems on the external bus, but it can probably be fixed with some resistors.

Notes:

* The 65C02 should run faster than the 1MHz clock of the Vic-20. 10MHz should be possible.
* I will add a battery to keep the SRAM memory alive, even without power. It should enable some program at BLK5 to autoboot.

@kakemoms

Looking good, wil follow this with excitement.

Well, debugging is kinda slow but it seems to get closer each day with the bus interface and memory mostly done:

Strange thing happends if the databus (D0-7) opens at wrong times. Most noteably the character colours gets randomized. I didn't think the 6561 could see the external memory, but it looks like it can somehow..