Date: Wed, 31 Jan 1996 19:32:41 -0800 From: "Jordan K. Hubbard" <jkh@time.cdrom.com> To: Poul-Henning Kamp <phk@critter.tfs.com> Cc: hackers@FreeBSD.org Subject: Re: Watchdog timers (was: Re: Multi-Port Async Cards) Message-ID: <2257.823145561@time.cdrom.com> In-Reply-To: Your message of "Wed, 31 Jan 1996 21:32:40 %2B0100." <5377.823120360@critter.tfs.com>
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> I actually thought about this some time back, and have a suggestion > for a ISA card: If you're going to go to all that trouble, why not simply add a low-cost CPU and a serial port to it? Then you could also hook an external modem to it and use it as a full-blown dial-in diagnostic port for stopping the system in its tracks and sniffing around (or poking at the corpse). I'd imagine the costs of laying out and fabricating the boards would add such a "knee" in the cost curve that another $100 in parts for several orders of magnitude's worth of extra potential functionality would be a more than reasonable trade off. Pyramid did/does something like this for their RISC monsters. They have a 68K machine driving a color console which provides the fanciest interface for grubbing around in the internals of a machine/UNIX OS that I've ever seen! The only drawback to theirs was that they didn't really document how to get down and dirty with the 68K system (for obvious reasons, I guess) so you couldn't really use it as an OS developers tool, but I rather doubt that any FreeBSD related project would make the same mistake. :-) Needless to say, it would also run FORTH. :-) Jordan > > The "FreeBSD gadget": > > Watchdog, can be set to timouts of 1s, 10s and 60s or > something. Will launch a RESET, NMI, or IRQ (jumper). > > 10, 100 or 250 Mhz timer, with readable count, > generates IRQ 20/100/250 (jumper) times a second. > (For microtime) (Maybe even with a 10/11 swallow > counter along the lines the XNTP people suggest.) > > NVram for console. 64K of NVram (preferrably FIFO), > for console-messages, not affected by reset. > > Optional: A microcontroller to make a async console > with the above nvram. (incl modem handling and passwd) > Possibly even with a BIOS-eprom to even make the bios > available that way. > > Optional: NVram for acceleration of NFS &c. sockets > and a battery for 4-8 Mb ram. Possibly with a little > clock to do refresh so DRAM could be used. (cheaper) > > Now, if produced in some decent quantity, the price might be right... > > How many ISP's would buy one ? > > I'm not going to make it, I'm SW only, but I'd buy a couple right away. > > Any takers ? > > -- > Poul-Henning Kamp | phk@FreeBSD.ORG FreeBSD Core-team. > http://www.freebsd.org/~phk | phk@login.dknet.dk Private mailbox. > whois: [PHK] | phk@ref.tfs.com TRW Financial Systems, In c. > Future will arrive by its own means, progress not so.
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