FPGA VAX update

-----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Holger Veit Sent: donderdag 3 november 2005 14:08 To: On-Topic Posts Only Subject: Re: FPGA VAX update woodelf wrote: to get one About thirty years ago, when I was pretty much younger :-), I built a classical TTL computer (with 74181 ALUs etc.) almost from scratch, basically from schematic fragments from the TTL databook and TTL cookbook and some electronics magazines; well - if it were really from scratch, then even so "highly integrated chips" like the 74181 were prohibited as well. Looking back, this had almost all characteristics of a real computer. There are two aspects IMHO why this does no longer happen today: - what was a known magazine in the past, would today perhaps realistically called "Un-Popular Electronics", the knowledge of electronics from the ground up is dying out; and with the continuing "digitalization" of technology, it is an ever increasing hurdle to get started - the classical AM detector radio I built as a newbie will nowadays no longer attract anyone - you can get a gadget which is better by several magnitudes for a fraction of the expenses you'd have for soldering your thing. - The tools you have are too user friendly (!); i.e. you could rather easily click something together, be it software or VHDL code for an FPGA without ever needing to understand what is really going on. The "soul of a new machine" guys that traced glitches with a logic analyzer in a large wire-wrapped TTL graveyard are gone - such a machine had the necessary wow factor. No surprise when a VAX in an FPGA - see subject - is not really interesting. It is possible - that's it. But what does one gain? It is like solving a 10000 pieces puzzle; spend time and don't learn really much. When Hillary climbed the Mount Everest 50 years ago, it was something new, extraordinary. When tourist nowadays use sort of stairways to reach the top (okay, it's not *that* extreme now), it is just uninteresting. But standing on the top, is still a challenge and an experience for the individual. However, what we lost now is a sense of wonder - that small ALU based TTL circuit was built by myself, and I did it, and it is irrelevant that some idiot could download a digital simulator and click the same circuit together on a PC screen. I guess this is what makes the difference between a real PDP-11 with some ridiculous 5MB storage disks compared to a SIMH emulator running on a 3GHz Pentium. Watch the blinkenlights. Holger