6502.org

Thanks YT.
To summarize that Hackaday article (but not the comments): we have the Mercury DIL-format module for $65, based on Spartan-3A and with 512k x 8bit SRAM, and 30 I/Os which are 5V tolerant; and we have the XuLA2 DIL-format module for $120, based on Spartan-6 and with 16M x 16 of SDRAM and 33 I/Os - not 5V tolerant!

There's a board I'm preparing to connect with a audio I/O board, called the Papillio Pro - it's $85 with a Spartan-6 chip - it has limited I/O devices on the main board, but it designed to stack I/O boards on top, like the arduino platform does.

Here's another board, made in Scotland and selling for £100:



It has 72 I/Os, a non-volatile FPGA and a 16-bit wide SDRAM. See also https://plus.google.com/116069803225736 ... MSGKU7hVC5

Double-size FPGA for an extra £12.

(Those I/Os are almost surely not 5V tolerant)

Hmm 100£ that is a bit expensive for such a product.
I find the Mercury board much more attractive.

Over in the XC95xx thread we have news of a couple of boards enso has designed (and will sell), and also a note that the mercury board has a cost-reduced variant. See viewtopic.php?p=27836#p27836

Enso has as many as 3 FPGA board designs now:
DILDAR - XC3S50, without SRAM(*) see viewtopic.php?p=27849#p27849
CHOCHI - with SRAM see viewtopic.php?f=10&t=2740 and viewtopic.php?f=10&t=2770
MINEO - with 16bit wide RAM see viewtopic.php?f=10&t=2769
See also http://apple2.x10.mx/CHOCHI/

Also note the Papilio Pro which is a Spartan 6 LX9 based board for $85, with 3.3V i/os and a 16-bit wide SDRAM - it also has a large EEPROM for Multi-Boot capability. (At boot time, a chooser application can be loaded which then loads one of several alternate bitstreams)
http://store.gadgetfactory.net/papilio-pro/

(*) Applied correction from enso's reply.

To clarify, DILDAR boards have no SRAM. The early CHOCHI prototype grew out of DILDAR and bore DILDAR markings, confusing the issue.

DILDAR - XC3S50 with 100MHz 6502 core (Arlet's), 8K BRAM, clocking, 63 IO ports and 3.3V power is for control or embedding into larger circuits;
CHOCHI - XC3S50 with 45MHz 6502 core, uSD, 128K SRAM, 31 IO ports and USB,5V or 3.3V power is a standalone computer;
MINEO - is like CHOCHI with 256K SRAM, more IO and a larger XC3S400 FPGA - is still being prototyped.

All of these boards boot up as a 6502 computer with a serial port bootloader.

My goal is to make FPGA power available to the 6502 community and encourage development, and I will continue to provide $20 DILDARs and $25 CHOCHIs to members of this board for as long as possible. While the XC3S50 chip is not sexy, only 1/2 is used currently for the core and IO; it's a pretty good starting point for 6502 users wishing to get started in programmable logic, and all the software and the hardware is completely open source. It also ensures minimalism.

Projects are under way to provide an SD-card filesystem/loader, VGA output and emulation of 65xx chips. If you have time, interest and 6502 software (or hardware) to contribute to the project, please join us!

Thanks for the correction - I've edited my post.
I like to note the MINEO wide memory interface because of the possibility of using it as a 65Org16 starter kit.

Yes, the purpose of MINEO is 65Org16 indeed. The first board is not quite working yet; I will keep you posted.

Great!

On the MINEO are the address and data lines separate fpga inputs/outputs for each ram chip?

MINEO is still in development, so nothing is fixed. The SRAM is more of a breakout convenience for now and may be connected differently in the final board. For now, the address lines are shared so that the two chips are seen as a single 16-bit SRAM.

The one I use is extremely cheap (much cheaper than others on this thread?) at only £12 including postage ($18 ish?) that I have used on my UK101 recreation (http://searle.hostei.com/grant/uk101FPGA/index.html see hardware thread). Uses a Cyclone II FPGA.

Nice and cheap so can be kept set up for use in projects as-is. Can be used without having to worry about frying a very expensive dev board.

Nothing else on there apart from regs, 50MHz oscillator and the configuration chip (underneath), which personally is how I prefer it so that there is no dedicated hardware already allocated to pins.



Works really well for me, and enough on-chip to allow me to run several 6502 cores, or a full CP/M implementation with an external SRAM, serial interfaces and SD card etc...
Been so useful to me that I have bought several, and all are in use.

...just my input to this.

Regards.

Grant
http://searle.hostei.com/grant/index.html

I think Grant's choice of board is this one, mentioned elsewhere: (or of course you can buy the board only, for even less, if you already have a programmer or have a cunning plan.)
Cheers
Ed

As noted elsewhere: Thanks for the tip: here's a search URL for FPGA on tindie:
https://www.tindie.com/search/?q=fpga