Am 04.01.2014 02:09, schrieb Philipp Hachtmann:
On 03.01.2014 00:14, Andre Schaefer wrote:
I used an FPGA board from ztex.de for recovering
data from a Diablo 44
drive bit
by bit and for simulating a DG disk subsystem.
After reading this sentence I
immediately knew who is writing...
There are not too much active DG focused people around anyway...
I always come
to a point where I
think a high performance CPU could run simh, a large FPGA could
swallow all the
vintage hardware. For just solving the problem it's fine, but it
somehow hurts
my eyes.
For service and repair purposes I don't see a problem plugging a
high
performance computer into a vintage machine. It's just a modern tool.
True! You will have a PC with all the fancy development tools nearby
anyway, so where is the need for an on-board CPU? Use the PC as
controller. Just buy an FPGA board with high-performace USB and plug it
on a cheap 2 layer PCB with custom interfaces.
For a stand alone board I would go for a soft CPU core unless high
performance is required. I spend a few restless nights searching the
holy grail. Didn't find it. FPGA vendor cores are usually not portable.
The Leon3 (Sparc V8) is a nice CPU, it even runs Linux if you want.
Consider the license for commercial use. We heavily use Leon based chips
at work so I can't even hear the name anymore. Has a great debugging
tool (GRMON). OpenCore's Plasma (MIPS) is around for a long time, still
maintained, and comes with an RTOS and TCP/IP. It's on my "to be tried"
list.
For simple control tasks I use the J1 ported to VHDL. I'm really not a
Forth freak, but I have a soft spot for Forth CPUs. In the past,
numerous space projects used Forth CPUs. What is good for them should be
good for me.
BTW, if you have a sense of humor and want network, use a 6502 core at
40 MHz running Contiki.
Andre