More Boards

The FPGA Boards page lists the boards that I’m currently focusing development on. But there are several other boards that I do maintain things for in the source tree, and that will work fine for a nice PDP2011 system. And, depending on your needs, some of these might actually suit you better than the ones on the FPGA Boards page – but you’d probably have to do some tinkering to get everything put together.

Terasic/Altera/Intel boards
Terasic makes very nice boards, but one of the things that I really don’t like is their habit of creating confusion with their product names. There are for instance boards named DE0, DE0-Nano, DE0-Nano-Soc, DE0-CV, DE10-Nano – and all of those are radically different. So take care which one you get…

DE0: A very nicely built board – nice, small and elegant. Unfortunately ‘small’ also goes for the FPGA at 15k LE. For years, I used it to run a complete system of 11/70, RP, DEUNA and console terminal – brilliant for my desk top 211BSD system, and also for demonstrations – you’d only need to bring a ps2 keyboard and hook up to a vga monitor. But with the latest changes, it won’t fit all of that any longer. Still a nice board, but with limitations.

DE0-CV: The successor to DE0, and based on the same design principles: small and elegant, but in this case with a big Cyclone-V on – about three times as big as the Cyclone-3 on DE0. One nice extra compared to DE0 is the extra two 7-segment digits – perfect for showing a 16-bit value in octal… but it also has a mini-sd card slot instead of a regular size.

DE10-Lite: A really nice small board with switches and leds and six 7-segment digits and a VGA connector. But no sd card or PS2 connectors. Before CYC1000 it was one of the cheapest options for PDP2011, and just a bit more blinkenlights than a DE0-Nano. The MAX10 FPGA is huge, and it has built in configuration storage that makes it boot very quickly.

DE1: DE1 was the first Terasic/Altera board I bought, and I was very pleasantly surprised by the build quality. The board has just about any peripheral on it that you would want – static ram, dynamic ram, flash, 7-segment displays, leds, switches, buttons, RS232 DB9, VGA, PS2, sound, sd card, SMA… and expansion ports too, obviously. The only minor drawback is that the FPGA is aging a bit – it’s only a Cyclone-II, and it won’t run at the same speed as the current Cyclone-10 generation will. Terasic seems to have stopped selling it, but there might still be some to be found – and certainly second hand. It used to be very popular, and that means you can find many other projects that run on it.

Cyclone V GX: C5G was a very early Cyclone-5 board and I got one just for that reason. It has a big FPGA at 77k LE – probably the biggest one I have. But it also has LPDDR2, and I don’t support that; I did look into how I would need to interface it, but I didn’t finish the work. It also has 4Mbit of static ram, so it’s still somewhat usable even without the LPDDR2 – at least, the 18 bit systems will run nicely on it.

DE2-70: The upgrade version of DE2 (which I don’t have – the board directory for it is a contribution). With it’s 70k LE Cyclone-2 FPGA it is aging and big, and for a reason I’m not sure I understand the toolchain runs very fast for it. So I still like to use it for development – and all the displays and blinkenlights and switches tend to come in handy for that too.

Digilent/Xilinx boards
Digilent is famous for their PMODs that flexibly connect just about any peripheral you could think of directly to their boards. And their S3Board was the first board that PDP2011 ran on. More recently however their newer FPGA boards are overpriced IMO, and I’ve not kept current on them. The older boards still work fine though.

S3Board: officially called the Spartan-3 Starter Board if you got it directly from Xilinx like I did – but Digilent also sold versions with larger FPGAs on. The one to get was of course the 1000K gate version… and that one is still useable for a somewhat downtuned PDP2011. Mainly still there for nostalgic reasons – as I mentioned, it was the first board that PDP2011 ran on.

Nexys-2: Also sold in different FPGA sizes, and the 1200 is the one to have. It has 4 PMOD connectors – and it can connect to an expansion card for more, although the cards might be difficult to find now.

Nexys-3: I never got along with this one – the FPGA is too small really, and the toolchain didn’t work nicely with the config flash part. But you can plug in an USB keyboard directly to it, and it will automatically convert to the PS2 protocol that PDP2011 can work with.