ebay - cardamatic

From: woodelf <bfranchuk_at_jetnet.ab.ca>
Date: Tue Feb 15 20:06:12 2005

Tony Duell wrote:

>I've seen the same with hardware, particularly FPGAs (IMHO nobody should
>be allowed near an FPGA until he cna design properly with TTL!). I've met
>'desginers' who say things like
>
>'Let's stick a D-type on that signal and see if it helps at all'
>
>'I'll swap that NAD gate for an OR gate, it might do some good'
>
>'Maybe inverting that clock will remove the glitch'.
>
>Oh well....
>
>
I have heard some TTL logic designs where very bad too.
 From what little I have seen FPGA's 99% is VHDL and VERLOG
for development. At least with a schematic you could trace out the
logic, I can't make hide nor hair of what the logic is with the
high level logic and you STIIL have to write code at the bit level
since you can't declare things like an adder. Then if you declare
something you never know just what the compiler is doing. The solution
for most designs ( all Z80's , 6809's or 6502's) is get a bigger fpga
and put your ( instert any classic computer design that had cheapest
keyboards
, tv display and flakey I/O) in a new chip that does all.
Right now I am designing with CPLD's and I like that better than FPGA's
since the parts are smaller and easyier partion your logic with.
My currernt design is a 18 bit machine with 3 6bit slices, 1 control CPLD
and a CPLD that is a 64x9 bootstrap rom and glue logic for the front panel.
CPLD design is not the hard part, finding places that ship electronic parts
to the "great candian north" with out needing a credit card OR a $100
min order and not having to pay $50 just for customs is the hard part.
I got the CPLD's ( pats box) but now I need the hard parts - panel led's
and switches
and memory.
Ben alias woodelf.



>-tony
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Received on Tue Feb 15 2005 - 20:06:12 GMT