Ghetto eprom erasing
[Note: As we all know cameras and I don't exactly work well together but i've tried to at least get semi-focused shots.]
I have been messing around recently with Psion Organiser2's. I'd wanted one when i was younger and they first came out but I had better things to spend my money on at the time (Girls, Beer and travel). Anyway I recently picked up a couple along with a couple of programpaks, rampaks and some datapaks. The rampaks are just battery backed up SRAM and the you can read/write to them willynilly as much as you like as long as the battery is still functional. Programpaks are normally PROM (or ROM) so you don't really need to worry about writing to them as you can't but the datapaks are EPROMs, so like the rampaks you can read/write to them however there are certain caviats. reading is fine, you can read from them until the cows come home and a couple of months beyond and writing is ok too, it'll drain the battery in the Organiser a  bit but no real problems, where there is a difficulty is that when you delete a file on a datapak it isn't really deleted it's just unlinked, the space isn't freed it's just not available so eventually you will have a datapak that you can no longer write too. When Psion were making and selling the Organiser they also made and sold a datapak eraser that was really just an eprom eraser in a psion labelled box and a 20 minute timer. I don't have one of those and I haven't seen one that runs on American voltages anyway and I no longer have a bog standard eprom eraser either so I needed to either build one or buy one. The thought of buying one does go against the grain for something so simple and the ones on evilbay looked like they either sucked, were unsafe or the drawer for the eproms would be too shallow. So I set about looking for instructions on building one. I found a link to some instructions to building one that looked quite nice http://highfields-arc.6te.net/constructors/other/epromerase.htm but I haven't seen a flashlight like the maplin one in the states for years and i wandered around a few pet stores and medical supply stores in the area and noone had the right tube anyway (i do plan on trying to find the parts to make the one in the link as it looks nicer than my "hack" but for the time being i'll use what I eventually ended up with.
Emulation (and Gaming) on the cheap
Over at hunterdavis.com Hunter has written a great post on using the dockstar as a gaming and emulation system. The dockstar is something I keep mulling on getting a few as they can be had for as little as $25 but i've not had the spare cash recently because what little disposable income i've had recently has been used to get psion organiser 2 and tandy model 10X stuff. I'm now definatly going to be saving my pennies for some dockstars (unless someone wants to send me a brace or two) though as i have a lot of emulators i use on a regular basis and i play wesnoth fairly regularly too. Even if you aren't that interested in Gaming and Emulation it's still a good article on the dockstar. the relevant post is here
serial terminal for IZ2S/EZ2S
I've eaten thanksgiving dinner (and cooked it too and done the washing up) and the wife is being a TV hog so rather than watch the rubbish she wants to watch I put on my headphones, fired up a belle and sebastian cd and looked for something useful to port to a stock zipit z2 running IZ2S or EZ2s. I finally decided that a serial terminal program would be useful. So here in all it's glory is a IZ2S/EZ2S compatable binary of ssterm.
The binary is here and you can just drop it into the bin directory on the sd card.
The Land of Green Ginger by Noel Langley
About 25 years ago I was dating a girl (CHM) who gave me a copy of the book "The Land of Green Ginger" by Noel Langley. It had been a traditional bedtime storybook in their family for a couple of generations. She actually gave me two copies, one dogeared and tattered copy that had been in her family for about 40 years to actually read and a newish copy to keep. I returned her "family" copy and reread my copy several times. Over the years what with moving and everything I misplaced the copy she gave me and although it's a kids book it is a fun book for a couple of hours for adults so i've spent a about 15 years looking for a new copy as it was out of print, i tried a few out of print services but they couldn't find a copy that wasn't disgustingly manky. a couple of weeks ago I was messing around on amazon and happened to type "the land of green ginger" and "noel langley" in the searchbox and up popped several copies along with the information it had been reprinted. I'm going to order a copy but before I do i decided to check the Brooklyn Public Library catalog and see if they had a copy, they do, several in fact. I placed a hold on it and was able to pick it up last saturday. I was involved with several other things until last night when I got a chance to sit down and read it. It is still as good as I remember it both for kids and adults. If want to buy a book for your kids or a nephew, neice, cousin, aged parent for Christmas it's a pretty good book to get them (make sure you read it before you wrap it, you'll thank me 
)
[Note: The reprinted edition available in the States isn't as nice as the "original" british puffin/penguin edition but I maybe just going all nostalgic and make sure it's the Noel Langley book of that name and not one of the myriad other boosk with the same name.]
Wikipedia page on noel langley
amazon link for "the land of green ginger by noel langley"
$10 Zipit Z2
I recently stumbled across a seller on fleabay selling what seems to be a seemingly infinite number of Zipits (after each sale there was an immediate relisting) for $9.99 + S&H (to NYC it is $5.95). The only problems were 1. they were on ebay 2. they were only available one at a time 3. they were on ebay.
However I did a little digging and found the seller has a "real" online store and are selling Zipit Z2's on there too. You can order multiple units and the shipping is combined and much lower than using ebay. I have passed this information on to one mailing list I am a member of and a few people in the #zipit irc channel has bought a few and they say they are the real deal and they arrive quite quickly.
You can never have too many Zipits so it might be worth picking a few up at that price. If i had a spare $60 or $70 i'd definatly buy a few as they make great christmas presents for nephews and neices.
USB charging cable for the ZipitZ2
I've made a usb charging cable but my efforts were terrible. a mass of electrical tape holding together a spliced plug off a broken power supply and a usb cable. It does work reasonably well though but recently a comment in my post about clocks for the zipit led me to a blog by a french zipit owner who has made a much nicer cable. my french is terrible, it's been over 30 years since I took french at school but from what I can workout he's selling them for 3 euros. I am tempted to send him a few euros and getting a couple myself.
Another console/tty clock program for the Zipit Z2
I stumbled across a program called tbclock this morning and decided to see if it would run on the ZipitZ2, there is no reason why it shouldn't as it is ncurses based but i've come across quite a few ncurses based programs that aren't too keen on the default character resolution of the ZipitZ2's LCD (changing to a smaller font normally fixes the problems but my eyes aren't as good as they used to be so alot of fonts aren't exactly usable for me, others might be able to cope with smaller fonts than the default 8x8 font). There were no problems with building it using the instructions on the webpage and it runs really well on the Zipit console and via an ssh session. tbclock is not only a binary clock, it is also a game and a "stopwatch". You can download the IZ2s/IZ2se,EZ2S compatable binary here and it's manpage is here. just drop the binary into the bin directory on your sd card and all should be good.
Two console/tty clock apps for the ZipitZ2
I recently needed a clock application for my zipit. I found two ncurses based ones that do what I want. tty-clock and clockywock (work via ssh and on the ZipitZ2 LCD, fit the ZipitZ2 LCD, look prettyish, work). Personally i find that i prefer tty-clock (which is surprising as i am definatly an analog kinda of guy when it comes to time pieces. There is just something about a second hand whizzing around and the guestimation required to guage the time that appeals to me at some instinctual level). I've built both and they are compatable with all versions and variants of Z2Shell, IZ2S and EZ2S so you shoudl be able to just drop them onto any sd card running those shells.
The download for tty-clock is here and clockywock is here
4tH for the ZipitZ2
[ Thirtieth in a series recreating the lost posts -- This was originally posted 21/07/10]
I've built 4tH for the zipit. I haven't modded the editor for the Zipits screensize yet as I just wanted to check that it built and ran correctly before making any changes. It seems to be running well so far and all the examples work (or at least the ones i've tried, which is about 90% of them).
4tH is a Forth Compiler and Interpreter that is almost fully ANSI Forth compatable and has been ported to MS-DOS/FreeDOS, Windows, Linux, OS X, AIX, BSD, BeOS, RISC-OS... and any programs you write will run on any of the ports with no recompiling.
My build runs on a Zipit running Z2Shell, IZ2s, IZ2Se and EZ2S, in other words any zipit that hasn't had it's kernel/initramfs or bootloader upgraded and can be downloaded here
Mounting a raw disk image
[ Twentynineth in a series recreating the lost posts -- This was originally posted 09/08/10]
I have recently started moving my ZipitZ2 development from a combination of aboriginal linux, buildroot and scratchbox1 to a combination of aboriginal linux, buildroot and scratchbox2 which means I need a way to seed the development rootfs with a working rootfs. Now I could manually move files from a ZipitZ2 to the scratchbox2 rootfs but that is error prone as I might miss a file or two or I might mess up permissions and setting up device nodes etc. is a right PITA. The easiest thing to do is to use someone else's rootfs however they are normally distributed as a disk image with one or more partitions in the image which makes mounting them normally almost impossible a bit problematic especially with large disk images (this is not completely true any more if you are using a modern distro with the latest versions things like util-linux). However there is a nice linux program available (available in every linux distribution there is as it's an important command) called losetup that will let us use a disk image as if it is a disk.
We'll use mozzwald's ubuntu rootfs image as an example of how to mount a partition within a disk image. After downloading and untar'ing his rootfs image you need to mount the image as a disk using losetup
sudo losetup /dev/loop0 zubuntu-jaunty-basic-rc1_05172010.img
Once you have done that you can then treat the device /dev/loop0 as if it was a real disk, all the utilities and programs that manipulate disks in linux will work as expected. So what we now need to do is workout where the first partition (or any other partition we are insterested in) is located within the disk image. To do that we use fdisk.
sudo fdisk -lu /dev/loop0
we use the u option as we want to get the fdisk to talk in sectors and not cylinders.
To calculate the offset multiply the units (512) by the partition's start (243), which in this case gives us 124416. Detach the disk image from the loop device.
sudo losetup -d /dev/loop0
and then reattach the disk image to the loop device using the calculated offset.
sudo losetup -o 124416 /dev/loop0 zubuntu-jaunty-basic-rc1_05172010.img
and then mount the loop device as normal.
sudo mount /dev/loop0 /media/rootfs
and you are done and can copy the files from the disk image to wherever you want.
[update: there are other less convoluted ways to mount raw disk images if you have a recent version of util-linux on your system. after finding out the offset just use the offset option in mount. Geordy also let me know that volume 27:2 (Summer 2010) of 2600 magazine (towards the back of the issue) there is more clever usage of the loop back file system with regard to mounting an ISO as writable and tweaking some settings with it. ]