mbbrutman

13 ms·

1.
by mbbrutman 5mo ago
I got lucky here with the compiler detecting the problem given that it wasn't just limited to using a null pointer. Depending on the buffer offset being handed back, it could have hit anywhere in the data segment.
2.
Hunting a 34 year old pointer bug in EtherSlip(brutman.com)
38 points by mbbrutman 5mo ago|9 comments
3.
by mbbrutman 2y ago
Where is that published? I was using Github for references on DOS 4 as 3.3 isn't there yet. (Thanks in advance!)
4.
by mbbrutman 2y ago
I looked at the call before and after to see what they had set the buffer to, and they clearly set the buffer to point into what is code. The executable is only 5KB and it's tiny; they had plenty of space in the segment to use a diffe
5.
by mbbrutman 2y ago
Some day ... It took me months even just to get around writing up what I found ... I'm still puzzled by the jump on the segment register values. I need to trace through the entire path.
6.
by mbbrutman 3y ago
Cute article, but I'm not quite sure how you missed the mTCP HTTPServ program ...
7.
by mbbrutman 3y ago
I took 30 seconds of video with the beeping and the screen scrolling for posterity. I'll get it posted somewhere.
8.
by mbbrutman 3y ago
I'm sure I can go for a few more years until the next patch ... On a more serious note, the web server is the problem here. I've tried to run long periods of time before but eventually it would crash. I finally found a 10+ year
9.
by mbbrutman 3y ago
Sadly the project is mostly unrelated to my day job. I started mTCP at least 6 years before joining Google and at most of my time at Google is spent on much less fun things. On the plus side, when I finally do get around to building a clus
10.
by mbbrutman 3y ago
Maybe, with some qualifications. A machine that is powered on but serves almost no traffic would also qualify but not be terribly interesting. I'm just happy it's been surviving the hug of death for 12+ hours now. Given the age
11.
by mbbrutman 3y ago
Thanks ... I think people are having time-outs so it's not anywhere near close to perfect, but the machine has been running at 100% for five hours or so now and it is not crashing, so I'm happy.
12.
by mbbrutman 3y ago
There were several speeds of the V20, including the base version at 5Mhz. Using it as a drop-in replacement and keeping the system clock speed the same the NEC V20 would still give you a 15 to 20% performance bump because it used less cloc
13.
by mbbrutman 3y ago
There is a fan internally in the machine, but it was placed to cool the 5.25" floppy drive when it was in use. I have more open space in this machine because I am using a 3.5" drive instead. I also replaced the original fan with
14.
by mbbrutman 3y ago
The machine continues to receive the hug of death .. especially with our friendly Europeans waking up. Have faith, it's still running. (And it's been surviving like this for four hours now.) I've turned down the logging le
15.
by mbbrutman 3y ago
I bought my first NEC V20 in 1986 or 1987. It was my first time touching the motherboard of a computer which made it nerve wracking, but they were very popular at the time. I bought mine mail order through the Exec PC BBS, which I think w
16.
by mbbrutman 3y ago
http://floppy.museum also running mTCP HTTPServ, but on 80286 class hardware. (That was featured earlier this year on HN.)
17.
by mbbrutman 3y ago
Yeah, far too much for a little CPU like this. Never mind the horror of trying to port all of the libraries and keep them up to date. Although there are people are using Apache in front of their vintage computers to terminate SSL for them
18.
by mbbrutman 3y ago
486? Nah. 4.77Mhz NEC V20, which is just slightly faster than an 8088. This should tide you over: http://www.brutman.com/PCjr/pcjr_web_server.html The main page is the best link. You might want to try back later aft
19.
by mbbrutman 3y ago
The Xircom is pretty bad, as it costs a lot to do the I/O through the parallel port. Just using TCP/IP sockets (no disk access or processing) the machine can send and received about 42KB/sec. A better adapter can do nearly
20.
by mbbrutman 3y ago
A few things to consider here: * It's getting hammered. I didn't expect it to be this bad. * If it can't process things fast enough packets might be dropped. So the TCP/IP error rates are probably pretty high rig
21.
by mbbrutman 3y ago
No, it's a 2009 creation. When I started mTCP I did netcat first because it was simple. My first iteration of an IRC client wasn't much better than netcat. It has improved since then though.
22.
by mbbrutman 3y ago
Yep, a PCjr. No parity bit on the memory even. I have a love/hate relationship with the Xircom adapter. It's portable and great for machines without ISA slots, but the max throughput is about 40KB/sec. A nice, real ISA car
23.
by mbbrutman 3y ago
FreeBSD is crusty, but is it really bad enough to compare to DOS 5.02? Besides, who needs 32 bits when 16 will do ... (Not serious.)
24.
by mbbrutman 3y ago
100+ days of runtime on nearly 40 year old hardware not designed as a server exposed to all of the garbage coming in on port 80. Remember, this is a home computer from the mid 1980s. This thing is way outside of it's duty cycle. And
25.
by mbbrutman 3y ago
Yep, at this point it's just continually busy. For the next iteration I've got to put a better Ethernet card on it. The Xircom PE3-10BT device is nice because it's convenient, but the bandwidth would be 2x higher with a real
26.
by mbbrutman 3y ago
I have a small IRC client for that 286 if you still have it. Even has some Unicode support, but being limited to CP437 kind of limits it. ;-0
27.
by mbbrutman 3y ago
It's still beeping ... busy != dead. Right now it's getting hammered pretty hard. I haven't implemented the clustering and load balancing yet. It can serve 8 concurrent connections but that slows it down. It will queue a
28.
2,500 continuous runtime hours on a 4.77Mhz DOS web server(brutmanlabs.org)
123 points by mbbrutman 3y ago|90 comments
29.
by mbbrutman 3y ago
(Sorry, I forgot to preface this with Show HN) ** 2023-07-14 18:38 PDT The DOS machine is getting DoSed. It's still beeping and happy but it's busy. ** This website is hosted on a 39 year old PCjr running at 4.77Mhz and it
30.
1k hours of runtime on the PCjr web server(brutmanlabs.org)
1 points by mbbrutman 3y ago|1 comments

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