Some things that I have hacked around with

Over the years, I have found that fiddling with bits-and-pieces is probably much more interesting than doing any real work. I have collected together those things that I can remember (or can be bothered writing about) and put their descriptions in here somewhere.

Recent Hacks

Got around to looking at my Quicknet PhoneJack card again. It turns out that the 2.5.66 kernel ixj driver has broken isapnp support, but the kernel isapnp code has allocated some IO ports to the card. This means that if I comment out the isapnp detection routines _and_ specify the io ports then the driver just works. Yey! I can now continue fiddling around with my PABX program that I have not worked on for almost a year (thats how long the damn driver has been borken for me - and it has been much more borken than just the detection routines in the past). Soon, I should be able to decommission my permanent dialup link and get a phone line to play with - then I can test out the voice features of my modems and use the PABX program to connect me to the real world (yes, its silly..)
How do you tell if a UPS is working and it is just the batteries that are fucked? Oh, of course, you buy some more batteries. What do you do with new batteries if you end up discovering that the UPS itself is borked? Yeah, I have a handful of old UPS's most of which appear to simply have dud batteries. This is hampered a little bit by the fact that most of these cheaper designs actually use the battery current to power the monitoring system - which means that if the batteries are really flat, there is no monitoring system to detect the presence of mains power and start charging the batteries. Doh!
Finally got my hands on some working barcode scanners. Unfortunately, the best one of the bunch doesnt have its interface cable. It is a Symbol LS 2080 and has an RJ-45 socket on the bottom. Its a real scanning laser style barcode reader so I am trying to make it work but nobody seems to have the specs for the connector on the bottom.
Starting to get worried about how much power I am using. So I got out an ammeter and have some records of how much power I am using for various items
Got another of my spare LCD displays wired up and working. This one is a funny two controller in one package job to allow it to support 40x4. Also I wrote up the connections that I used and stuck them on the cables page
Oh, woe is me. My Speedtouch Home ADSL modem has died. Not only that, but it turns out to have only a 1 year warrantee!! I was horified because that ran out two months ago. Bugger.
Now that I have a fun USB thing to try and get going, I dug out a USB "docking station" with a non standard serial and parallel port interface, I am also thinking of getting out some of the USB modems I have lying around here. I have sniffusb working on my test system (** dont believe them when they say it works on winXP - lies , damn lies!, though a new debug viewer might be the answer, I couldnt test that because the device drivers I am using were giving the system the wobblies when I was sniffing under both XP and w2k, so back to 98 I go..) and have captured traces of both my current test devices. I have written a post processor script for the USB data that is much nicer (to me) than the couple of scripts I quickly found on the net.
Got a new toy USB camera - an "X-Eye" camera. Its tiny, and contains but one do-it-all microcontroller chip (a Sonix sn9c102 but the datasheet is pretty slim on actual details. Needless to say, there are no Linux drivers for this little thing, but at $35 I figured that it was a pretty good deal and I might even be able to write a driver for it.
Well, I now have a reasonable understanding of the arptables user interface but still have some corner problems. The question now is weather or not I try and gut iptables or ebtables for all the interface glue, or just write it from scratch myself..
Finally, I get around to looking at the linux netfilter arp tables. I have been using mac address matching in the iptables to do the job that the arp tables are for (and it is no where near as good a job as the arp tables could provide). Unfortunately it turns out that there are no known userspace tools for using the arp tables (!! - how was it tested then??). I'm going to have to look closer and maybe write something myself.
I am the proud owner of a 5 year old Sony Vaio. Boy are these things really nice neat packages. Pitty about the dead battery with more electronics in it than in my VCR (makes it hard to replace - $270 !!). The strange thing about this laptop is its bootable PCMCIA CDROM drive. It has no easy way to remove the HDD and I dont have a floppy yet, so it was an experience akin to using a USB-CD enclosure (see below)
Well, I think that I might try and make a 19k2 FM serial transmitter and if that works, I will have to make another one. I found them mentioned on a web site and it definitly sounds cheaper than buying a whole lot os 801.11b hardware (if a little slow...) with the added benifit of keeping up my project building skills.
Interesting times with a USB-CD enclosure. Boy are they slow when you only have USB 1.x, but I was happy to find that the new motherboards do actually boot of the CDROM OK, I was just unhappy when I discovered that the Linux kernel that I am using (2.4.20) doesnt want to work with a CDROM on the end of that convertor. I tried it again with a Hard-Drive and Linux picked it up without a problem. I probably now need to work out how to setup a USB-HDD so that it will boot OK (using LILO doesnt work because it gets the BIOS drive numbers all borked up) I will probably have a go at using syslinux for this
I bought a infra-red keyboard to use as a remote control for my DVD-playing computer. Unfortunately, it seems that something about that computer makes this infra-red reciever not work. Damn Compaq! Now I am left with having to go and buy a new CPU so I can resurect one of these old cpuless systems I have lying around, then I have to build it up with all the same software etc ...
It turns out that bochs is now quite mature. I have been playing with it since its recent 2.0 release and it is perfect for testing my bootable CDroms before I actually cut a disk
OK, I just got a fancy new phone with GPRS and all kinds of fun syncing abilities - now all I need to do is write the right orbex cgi-bin server so I can hot-sync my Ericsson T68 over the internet.
Finally got around to building one of those parallel port LCD display dodads. Most of the diagrams out there want some extra parts, I used only hookup wire, leaving out all the trim-pots and latches and so on, and it works really well. The only extra parts are a couple of pull-up resistors for the keyboard, but I probably could get away without them. Something that I could not get away without was an external +5v power - I was hoping to get enough power from some of the unused parallel port pins, but alas, it was not to be.
It seems that the DVD-Audio format specification will include something called MLP (Meridian Lossless Packing) which I can find a lot of marketing celebration of, but not much information about its technical format (so that I could evalulate it for myself)... Still looking...
I dragged an old Aztech UM9800 USB software modem out of the cupboard today. IT is based on a st7554 & 7550 chip pair and I was hoping to find some information about the required software interface (I want to build a voice mail box or a soft PBX). I managed to find the linux drivers for the modem (they dont work without major surgery on 2.5) and a product brief PDF, but still no programming information
I would have thought that USB Card-Flash readers would be reletively standard by now, but it seems that the device I have doesnt want to play nicely with the Linux USB storage drivers. Oh well... Must try again when I am not running an ancient linux kernel (Ha! 2.5.25 - positively ancient)
Fiddling with bootable CD images. Trying to find a disk partition tool that can be run from the isolinux prompt, without an OS (the Ranish Partition Manager might be able to do this, but I have some issues with the rest of that program that makes me want to find a better one. The Ranish Partition Manager is the best Partition manager I have so far found and the thing that annoys me the most is that the earlier versions of it (while being limited with todays sized hard-drives) did not have most of the faults that I currently find. Also looking for a Disk Editor program that can understand many filesystems and maybe be run straight from the isolinux prompt. Next task is probably to make a menu program for isolinux.
Well, I got wine going. This was a bad thing. Some of my games worked acceptably (Starcraft) so I played them for a while (winemine!) but then I started working through my old games. Of course, I ended up having to resurect my old Windows box (its been sitting in a corner for almost a year now..) and play some games.
Finally got around to completely reorganizing my "slow" SCSI chain to allow me to plug in and try an old flat bed scanner that someone had given to me. I now have a Wide-Narrow cable going to an old Sun CDROM (turned off - its only there for the plugs on the case) a High-Density Narrow to Low-Density Narrow (Centronics style) cable from the old CDROM to my tape and CD-R pack (which now has its original cable instead of a bastardized Ultra-Wide cable) and finally from that pack to the scanner. Imagine my suprise when I then discovered that the scanner was not color (serves me right for not looking up the model number). Quite happy with its performance though and it will serve my scanning needs (I want to scan important meat-space documents so that I can index and search them without looking at the horror that is my filing-cabinet). On the other side, I still need a High-byte-only Wide SCSI terminator if I ever wish to use a Wide device on this bus.
I think that having a kernel implemented circular log file is very useful, especially if you are trying to have an embedded device (I am). Here is a patch for the Linux kernel to implement this clog.patch
Many moons ago, I found the Hardware Book online that had cable information and connector pinouts. Eventually it disappeared, but I eventually it reappeared (at I never found the original author, nor did I find any reference as good. Today I gave up on looking for new information - I figure that as I find info, I can add it to my very own cable specification web page. Of course there is nothing in it right now (Doh!) but soon..
SMS OMTI3500. Recently, I have found that the linux floppy drivers are a little flakey, so I thought I would try and get this old SCSI floppy convertor running, giving me yet another SCSI device and changing the floppy driver to a sd driver (which is a little more stable, especially since I need it to boot with). It gets recognized, but doesnt want to read the disk. I can run scsiformat and it seems to initialize the disk, but the process hangs. Looking for more information, especially re the jumper blocks (maybe it is configured wrong for my floppy drive)
My Birthday! So of course, I spent some time updating my linux kernel (Geek!)

Much older stuff
Older stuff can be found in the old hacks page

If you are reading this page, you may also find that my list of sites with tech info is also useful

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