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Posted by: need4speed Nov 10 2003, 02:22 PM

I'm still a drooler, but I may have my first 914 in a couple of weeks if things work out.

And I'm already dreaming of building my own FI system (though the car I'm looking at is a 1.8 with what the owner says is a good, working L-Jet system).

And I'm wondering - has anybody ever seen an FI brain that uses an FPGA chip, instead of a regular chip designed for the task?

A buddy of mine works at Xylinx, and he explained to me about these FPGA chips - mostly used in routers and stuff - it's basically a big array of programmable gates, and you can load a program on by physically configuring the gates a certain way, and then, instead of loading software in to run on the chip - the chip works as if it's a custom designed IC. I kind of thought I'd like to try using something like this - I'm not a really experienced programmer, but I have worked with computers for 12 years, and I've always wanted to take on a project like this.

Any thoughts?

Posted by: fiid Nov 10 2003, 02:38 PM

Most of everything built these days has a full-on microprocessor. The Megasquirt is based on a variant of the 68000 that has embedded eeprom and some ram.

You could build one with an FPGA, but you're probably better off just going the microproc route. All your logic is then embedded in software and it's even easier to mess with.

Fiid.

Posted by: Mueller Nov 10 2003, 02:41 PM

it sounds like a PLC but much smaller than the norm, not enough resolution if everything is either on or off

Posted by: SirAndy Nov 10 2003, 02:59 PM

yepp. a cheap-o 8-Bit 68000 clone. no FPU either. makes for fun floating point operations ...
good thing i used to do OS programming in assembler way before anyone even thought about a FPU

Andy

Posted by: fiid Nov 10 2003, 03:58 PM

FPUs are for wusses. :-)

You're right the CPU is a bit lame, but the new UltraMegaSquirt is going to be a lot better. They are taking their time over it though.

Fiid.

Posted by: sechszylinder Nov 11 2003, 02:52 AM

hilow,

I'm using fpga's since 10 years and I can tell you that you need lots of experience using those circuits.
BTW FPGAs are programmable logic circuits and they are not really well suited for a FI brain.
Most FIs using mircoprocessors or highly integrated microcontrollers, like megasquirt which uses a
68hc908 (6800 derivative, 8-bit architecture, it's not a 68000 clone, even if there is only one zero
missing in the name )

I would recommend to start with systems like megasquirt and if your are not satisfied then try to build your own ...

benno

Posted by: jkeyzer Nov 11 2003, 10:22 AM

Andy - Did you ever code on the Amiga?
I did not know you were such a hard core programmer. ASM, wow.

Posted by: SirAndy Nov 11 2003, 12:48 PM

nope, i missed the whole amiga hype
played some good games on them tho.

started out with a TRS-80 (anyone here remember those?) in '78.
then went on to the C64. did alot of ASM on that one, completely redid the kernel, shrank it to 2/3 (without loosing any functionality), then adding my own code.
added a assembler/disassembler and other "tools" to the kernel. made cracking games a piece of cake
then on to the early PCs. then MAC. then SUN Spark. then (insert a lot of crap here .....)

after all these years, assembler code is still my favorite,
Andy

Posted by: SirAndy Nov 11 2003, 12:51 PM

ooops, faux pas on my end.
somehow 68000 is stuck in my head. haven't done any ASM on those in years tho.
anywho, the MS cpu is 8 bit, which is kinda weak, but the good news is that they didn't fill up the kernel with too much stuff, still plenty of space in there for additional code ...

Andy

Posted by: jkeyzer Nov 11 2003, 01:05 PM

You hacked on the C64?! SWEET!!

I was either too young (my parents got a C64 when i was around age 6) or not exposed enough to the scene to ever get into it. I really wish I could have and I have huge respect for the people that did. Computers and computer programming was a lot more interesting back then in my opinion, but I am a hardware guy so I am biased towards hacking the hardware directly. You can't directly access much of anything anymore from what I am told although I have done pretty much no programming on the PC except under Linux.

I still load up some of the old Amiga demos on an emulator I have on my PC. When I was in high school I had an Amiga 2000 and then a 3000 (finally, a computer with a hard drive). I used to get on the net and read usenet, do irc, and browse with web with Amiga Mosaic. I finally switched to a Pentium 133 in 1996 but the Amiga still works. The C64 finally quit working this year.

Jeff

Posted by: fiid Nov 11 2003, 02:43 PM

Amigas suck. Atari STs were better.

LOL

Posted by: Hawktel Nov 11 2003, 04:08 PM

I had a Commie 64, and a trash 80. I'd never want to be a programmer. To much work for the money.

Posted by: jkeyzer Nov 11 2003, 04:12 PM

Your avatar makes it look like you still have a C64.

Posted by: redshift Nov 11 2003, 04:16 PM

lmao!

I had a Comode, my first real computer was a Mac 512.


M

Posted by: Hawktel Nov 11 2003, 04:17 PM

Ohh, you think its safe to Mock BATMAN!!!!!!!!!!

Okay maybe it is. I do need another avatar. I'll start looking.

Posted by: need4speed Nov 12 2003, 10:07 AM

Okay, well, thanks for all the info and comments guys.
(just got word that the owner of the 914 changed his mind, doesn't want to trade )

Oh well, another will come along some day. Gotta sell the Ghia first.