Discussion - Tape Drive

Tom M. — Fri, 28 Oct 2011 01:20:20 GMT

The 3B2/600 only knows the Wangtek 5125ES SCSI tape drive, and mine is getting flaky. It doesn't want to write tapes any more. So today I ordered a refurbished unit from Code Micro, and with a little luck, I'll have it in a week or so. Then I'll send the original off to be refurbished and will soon have two. Things with moving parts are always the most likely to break over time. I've got the disk drive problem fixed with a modern SCSI drive that I've got running - a 1.05GB Conner. But the tap

DSO Nano Firmware Upgrade

Tom M. — Sat, 22 Oct 2011 12:10:00 GMT

I've been looking for an inexpensive and compact oscilloscope to round out my test equipment collection. I'd seen some of the ones that are PC based, and wasn't really interested in something tethered to a computer - I don't have one on my electronics workbench. After a bit, I found the DSO Nano, an open source Digital Storage Oscilloscope based on the ARM CortexTM-M3 32 bit processor. It's not especially powerful or capable, but does the basics and is quite inexpensive: $89 delivered.

It has a 320x240 pixel color display, a micro SD card for waveform storage, is powered by a lithium polymer battery, and is rechargeable via USB cable. It has a built in, basic signal generator, and comes wit

Electronics

Tom M. — Wed, 19 Oct 2011 19:35:00 GMT

My undergraduate degree is in Electrical Engineering, but I really can't remember much of it. Heck, I graduated in 1980 and I really can't remember much of anything that far back. I guess I learned lots of theory: power systems, circuits, electromagnetic fields, solid state stuff - you name it.

Not too upset that most of it is hazy in my mind.

We also learned quite a bit about test equipment in our labs: oscilliscopes, signal generators, frequency counters, and a bunch of other doodads I can't remember.

That stuff I wish I remember better!

I've been playing with a variety of electronics stuff, mostly related to the N8VEM project and the Arduino, both very cool things to do if you like being close to computer hardware and tinkering. Follow the links if you want to know more about either project.Oh, never mind! I pulled out another keyboard, this one an old Dell here at the office, and it worked fine. I guess the PockeTerm hardware is a little choosey about what it works with.

Now I know I'll be playing with this thing on real hardware tonight!

More PockeTerm Progress

Tom M. — Thu, 26 Aug 2010 13:05:00 GMT

I managed to resolder the caps last night and then get the rest finished up according to the instructions. Initial power test was fine: on/off switch worked, and the LED lit when power was applied.

I then mounted the ICs in their sockets and plugged the thing into a LCD monitor and a USB keyboard with USB to PS2 converter.

Unfortunately, there was no signal to the display. Power at the 5v voltage regulator is fine.

So... tonight I'll try some different displays and if that doesn't work, I'll start checking the board for potential bad solder joints. If that doesn't lead anywhere, I'll go begging for help on the Briel site.

I'll post a picture or three now.

PockeTerm Progress

Tom M. — Wed, 25 Aug 2010 16:55:00 GMT

I spent about an hour last night identifying and inventorying all the components for the PockeTerm and beginning the assembly.

As I grow older, it gets harder and harder to make out the codes on very small resistors and capacitors. I've got one of those magnifiers that you wear like a huge pair of glasses to help. Luckily, mine came with three magnifications, so I was able to see the tiny writing on the tiny caps. I would never have been able to do it without them.

So, after getting it all straightened out, I fired up the soldering station and began. The resistors, switches, IC sockets, and the crystal went in fine. Capacitors were no problem till I got to the polarized tantalum caps, and soldered two of them in backwards. Oops!

So at that point I figured it was time to quit for the night. Tonight I'll desolder them and turn them around if I can do so without destroying them. I figure the PockeTerm will be completed and maybe even tested tonight. If I destroy

PockeTerm

Tom M. — Tue, 24 Aug 2010 02:15:00 GMT

A little company called Briel Computers makes a Propeller microcontroller based serial terminal call PockeTerm.

This is a tiny thing that draws almost no power, provides full VT100 emulation, and uses a standard VGA monitor and PS/2 keyboard for I/O. It connects via standard DB9 serial (DTE or DCE).

Mine came in the mail as a kit tonight. I inventoried all the parts and will likely solder it all up tomorrow. Pictures tomorrow.

This is the beginning of the N8VEM project!

More New Projects

Tom M. — Mon, 23 Aug 2010 01:50:00 GMT

While looking around at the N8VEM project, I also happened on the Arduino. The Arduino has to be one of the coolest things I've ever run across.

Years ago I played, very briefly, with a Paralax Basic Stamp. This is a micro controller that can be used to build fun circuits, and is programmed in Basic.

The Arduino is its big brother, and amazingly, all the hardware and software are Open Source. Well, not the individual chips, but all the boards, the development environment, the documentation, and tons of interesting circuits, machines and projects.

See much more at the Arduino Home Page.

I got involved because it's an easy way to get into reading schematics, examining circuit boards, and soldering electronics together. Sean and I have already built some pretty cool stuff with Arduino, including a couple of piggy-back boards, called Shields inthe Arduino language, some basic LED

New Projects

Tom M. — Sun, 08 Aug 2010 02:15:00 GMT

Sorry if this is a little bit off topic, but I'm pretty jazzed about some new projects I'm beginning.

It all started out with me thinking through how to get my 15y/o son away from World of Warcraft long enough to have some other kinds of fun and maybe learn something. He's got a great mind and does well in science and math in school, and says he might be interested in engineering (or medicine) as a career. So I started looking around for some projects we might do together that would be fun for both of us and that I could use as a vehicle for teaching him some technology.

Read on for the rest of the story...

Apple

Tom M. — Sun, 18 Jul 2010 21:24:59 GMT
A group for devotees of Apple Computer. Let's try to keep it to Motorola 68K and older

Apple

Tom M. — Sun, 18 Jul 2010 21:24:59 GMT
A group for devotees of Apple Computer. Let's try to keep it to Motorola 68K and older

Apple

Tom M. — Sun, 18 Jul 2010 21:24:59 GMT
A group for devotees of Apple Computer. Let's try to keep it to Motorola 68K and older

Discussion - Xenix

Tom M. — Tue, 13 Jul 2010 14:43:03 GMT
I recently came into possession of four SCO Xenix operating systems (one 8086, one 80286, and two 80386) in the form of disk images. If you're a collector of old Unix systems, have the correct hardware, and would like to run one of these, please contact me offline. These are still copyrighted and cannot be legally made available for general download.

Discussion - Z80pack CP/M Emulator and other tools

Tom M. — Fri, 09 Jul 2010 14:35:35 GMT
I've been experimenting a bit with z80pack, a nice z80 and CP/M emulator. It's similar to SIMH, and I wouldn't normally have thought of it, except that there is some software available for it that I really wanted to try. I've uploaded the sources (I compiled it under Linux) and a couple of other things: * cpmtools - a set of host operating system tools for managing CP/M disk images and files. * Microshell - a Unix-like shell for CP/M, including docs. Supports shell scripting, pipes, a

Alan Turing

Tom M. — Fri, 09 Jul 2010 13:20:00 GMT

Most serious computer users have probably at least heard of Alan Turing, but unless you're very serious or have a formal computer science education, you probably don't really know much about him and his work.

I was browsing about last night and came across this really good video about Turing, which does a great job describing his contributions to computer science. The video is interesting and does not require a degree in math to understand. Hope you enjoy it!

Amazon, search, and buy used. It's amazing what you can get for $.01 plus $3.99 shipping. And it's amazing how many old computer books from the '60s, '70s, and '80s are out there. I buy Unix and CP/M related books, and books about old programming languages like Fortran, Lisp, Pascal, and Snobol.

More recently, I've been getting back into running CP/M, both on real hardware (a Kaypro 4) and emulation (SIMH Altairz80). I also sometimes play around on a TRS-80 emulator running TRSDOS or LDOS. These are fun old systems and there's a ton of old software for them in various archives around the net. I have large archive

Discussion - Microsoft Fortran-80

Tom M. — Wed, 23 Jun 2010 19:37:55 GMT
I've been doing some programming in Microsoft Fortran for CP/M. It's been fun trying to remember how it all works. Microsoft Fortran seems to work quite well - it's a Fortran IV system with a little left out (complex numbers) and a few things added. In general, it works as expected. For anyone wishing to play around, I've uploaded a zip file containing the necessary files, and a scan of the entire documentation set in pdf format. You can find it on the Documents tab of this Group. The bina

Discussion - I must consolidate

Tom M. — Sun, 06 Jun 2010 02:27:27 GMT
I have one too many Sparcs. The Sparc 20 is physically and cosmetically in much better shape, but it has a dead NVRAM, a single 125MHz processor, and a motley collection of RAM sticks totaling 224MB. It has a big, new, 4.2GB SCA drive and a 2.1GB drive with a lot of bearing noise that I don't trust. The Sparc 10 is older, cosmetically in much worse shape, but has a good NVRAM chip, 4 100MHz proocessors, 4x64MB RAM sticks, and two decent drives, a 2.1GB and a 1.05GB. I've also got 2 125M

Early UNIX Documents

Tom M. — Sat, 30 Jan 2010 21:45:00 GMT

If you're reading this and are really interested in early UNIX systems, you have probably read some of the early UNIX books and papers. Things like Don Libes' "Life With UNIX", or Peter Salus' "A Quarter Century of UNIX". These are all great books, and if you haven't read them, many can be had for a song on eBay or as used books on Amazon. Basically these are so cheap that you end up paying only shipping. Great deals.

Discussion - Some Sparc 10 Woes

Tom M. — Tue, 01 Jun 2010 01:46:26 GMT
An unfulfilling day here at wyvern. Tried to get the Sparc 10 set up a bit better and spent much of the day working with partitioning disks. Why does this have to be so hard, and where is the documentation that tells you that the b partition is the swap partition and other funny things you need to know to get a non-standard drive working? After getting everything partitioned and SunOS 4.1.4 installed, the machine started giving me a "network connection not found" error, or something lik

Discussion - Disks and filesystems

Rudy S. — Mon, 31 May 2010 14:11:12 GMT
I tend to forget how and why we used to do things in the Unix world. I was busy building a new, old Unix system this weekend and had to partition the main drive. I've gotten used to just using the whole disk on my Linux systems. I mean why not? If I've got a gigabyte or more that I'm pretty sure I'll never fill up, there's no issue. But in an older, production system, there were no big disk drives. You almost never had enough, much less too much, disk. So I'm having to remember more abo

This Old Micro

Discussion - Tape Drive

DSO Nano Firmware Upgrade

Electronics

More PockeTerm Progress

PockeTerm Progress

PockeTerm

More New Projects

New Projects

Apple

Apple

Apple

Discussion - Xenix

Discussion - Z80pack CP/M Emulator and other tools

Alan Turing

Discussion - Microsoft Fortran-80

Discussion - I must consolidate

Early UNIX Documents

Discussion - Some Sparc 10 Woes

Discussion - Disks and filesystems