Newsgroups: comp.sys.transputer From: David Boreham Subject: Re: Transputer - alternate source? Organization: Netscape Communications Date: Thu, 22 Jan 1998 16:09:12 -0800 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <34C7DFA7.455EC019@netscape.com> pete wrote: > the following quote got me thinking > If we could get hold of a Verilog or VHDL definition of the T425 and/or > T805 then we could make our own, with a sufficiently large FPGA. There > are a number of FPGA implemented processors (6502 and Z80 are dead easy > to do, apparently) and the rate at which FPGAs are getting bigger, > enough gates to do a transputer shouldnt be far away, even if they arnt > big enough now. I wonder... Looking at the Xilinx web site, I see that they offer a part designated XC40125VX, which seems to be the current state of the art. This is advertised as having 11000 "logic elements". Now, looking at http://www.vautomation.com/v6502/v6502pcb.htm, it seems that a 6502 fits in an VC4013, which Xilinx say has 1368 logic elements. Now, let's assume that the number of logic elements may be compared directly. This would make the 40125 capable of implementing 8 6502's worth of processor. Note that this synthesized 6502 runs at a blistering 3MHz implemented in an FPGA. At http://www.vautomation.com/press/96_09_17.htm we see an 8086 implemented in five 4013 devices, indicating perhaps that there is reason to be hopeful that an 8086 might be implemented in today's largest FPGA, albeit rather slow-running. I'll take a wild guess and say that a T425 has ten times the gate-count of the 8086. The T805 would be perhaps 1.7 times that gate count. Now, I wonder how fast a 6502 would have been if implemented in the T4/T8 process? I'll guess at 50MHz. So, if FPGAs get ten times as dense and ten times as fast as they are now, then you might well expect to be able to synthesize a T425 into one and have it perform as fast as a real T425. This means that someone has at least three years to write the VHDL, which is probably just enough time !