Current Board Status
Here is a brief, chronologically sorted, summary of the boards I use (or used) in the w11 project:
| Date | Board | Status | Comment |
|---|---|---|---|
| 2007 May | S3BOARD | dormant | My very first board, the entire initial w11 development was done with it. Performance of the rlink over a 460k Baud RS232 link is modest, enough for initial proof-of-principle studies, but somewhat slow for practical usage. See also picture. |
| 2010 May | Nexys2 | active | The Cypress FX2 USB interface provided a real performance boost, the rlink concept finally worked out. Full usage of the 22 bit address space thanks to the easy to interface PSRAM memory. See also picture. |
| 2011 Nov | Nexys3 | active | Great Spartan-6 based board, with easy to interface PSRAM memory. There was also a modest increase in performance, with the w11 system clock increasing from 50 MHz to 64 MHz. Of all my boards, this one has the smallest FPGA size, the current w11a design uses 93% of the slices. The w11 will outgrow this board soon. |
| 2015 Jan | Nexys4 | broken | The first Series-7 based board. The initial development was done with ISE 14.7, but quickly switched to Vivado. A much better IDE, code development was fun again, essentially the entire development was done on the Nexys4. W11 system clock increased to 80 MHz. The board broke unfortunately in July 2019. |
| 2015 Jan | Basys3 | active | Just cute. No onboard memory, so w11 sees only 176 kByte memory implemented with BRAMs. |
| 2016 Feb | Arty A7 | active | This board has the best value for money ratio of all my boards. It took quite some time to get the DDR3 memory interface operating, but since then this board has been one of the main development boards. Very nice is the built-in current monitor. |
| 2017 Jun | CMod A7 | active | A real gadget, certainly the most compact setup I have. The 35T die size is more than enough for a w11. The 512 kByte onboard memory combined with some BRAMs result in 672 kByte visible to the w11 CPU, enough to run a trimmed down 211bsd system. |
| 2019 Aug | Nexys A7 | active | The Arty board is nice and from a purely functional point everything you need. But I like the LEDs of the Nexys series boards, the perfect board for a blinking lights w11. So I ordered a Nexys A7 board, formerly known as Nexys4 DDR, to replace the broken Nexys4 classic. |
