Tag: computer

Duo BASIC – 8 Bit Microcomputer

It’s implemented across 7400 series logic. It’s pretty cool.


I had to assemble the whole thing. About 500 solder connections. Took about 3.5 hours. So doing the math that’s 142.86 soldered connections per hour, 2.4 a minute. That’s because you have to prep the components by taping them to the opposite side, then soldering the pins, trimming leads etc.

I’ve applied power and done the smoke test. One LED doesn’t work. I may have killed it with the heat. But I can replace it, just gotta make sure I put a 1K resistor on it. But otherwise everything works. I’m able to watch the PC LED’s count upward. So it’s executing code.

It only has two instructions – MNZ or Move Not Zero and ADD. It has 3 registers, A, B, and PC. PC is Program Counter btw.

The logic is all discrete. You have buffers, inverters, schmidt triggers, adders, etc. And I want to see if I can write to the EEPROM. If I can I could add command like JMP, JNZ, etc. A half dozen more commands would make this a kick ass machine.

And you could potentially tap the LED outputs and run it through say an Arduino with LCD attached and have a rudimentary display for it.

I’m just learning how to flip the switches and commit things to memory. Lots of fun!

Fixing ancient laptops

I’ve had this laptop for a long time. I’ve done preventative maintenance on it and repairs where necessary.

One of the things that drove my nuts about it was the screen hinges. The things were just worn down, the screen would flop any which way.

Searched the web and found a new set of hinges for $10. It took the removal of 12 screws to do this, the ones on the screen surround, and the screws holding the hinges to the rear of the display cover and those that secure the screen to the chassis of the machine.

And as I’ve said – I understand the limitation of XP and 32 bit architecture. But it still does what I need it to do without any major issues. And I was of the firm impression that Vista was a piece of crap, Windows 7 was acceptable but unnecessary to upgrade to that as it was a bit bloated, and Windows 8 looks like it was designed by a crack addled ADHD sufferer. And that’s me being nice about it. In my opinion XP was the pinnacle for Microsoft. And it’s been down hill every since.

What Microsoft doesn’t realize is this:

1) An operating system has a very LONG life span. And just shoveling new OS’s out there that in essence were half baked pissed a lot of people off.

2) The cycle for I.T. infrastructure isn’t two years, it’s more like 4-7 years.

It is entirely likely that my next computer will not run Windows. Or at least not as the default operating system. Instead I’ll probably get use Debian Linux and VirtualBox on it. VirtualBox is a virtualization package that lets you run another OS image underneath the main OS. So I’ll just clone my current XP box into an image and use that when I need to get access to MS Office, etc.

And I will kiss goodbye forever Microsoft’s craptastic operating systems. Yes I said it, I’ve dealt with Windows for over 20 years now and all I can say is that it’s been one pain in the ass after another. From print drivers that no longer work with the latest versions of Windows, to bad file system structure, etc.

Linux at the very least is flexible as hell. The ext4 file system can have drives up to one exbibyte (EiB). That’s that EiB is 1 exbibyte = 260 bytes = 1152921504606846976bytes = 1,024 pebibytes. A pebibyte is is 250 bytes. And right now we’re only seeing terabytes and gigabytes. So there won’t be any problem with big files in the ext4 file system.

Plus ext partitions have journaling capabilities, error correction, etc. Compare that to the Windows File System.

I can just use Macrium Reflect to create the boot image of this machine – and BAM! Virtualized in style.

So I’ll be leaving Microsoft for greener fields. And in fact once I image this machine I’ll probably put Ubuntu or Debian on it. It’s still usable.




Cox incoming email down

So last night I noted Thunderbird kept telling me it couldn’t connect to Cox’s email server. Now I run a spam filter so I telneted to the spam filter and it responded. But then I tried initiating a POP3 session from the command line to Cox’s smtp.east.cox.net.  That failed spectacularly.

So now I know Cox proxies all web connection because I occasionally get a web pop-up stating they know about the issue and are working to resolve it.

I can give them a hint, ditch InterMail and go with Qmail.

RasPi First Boot

After the trials and tribulations of stuffing the Debian Wheezy operating system image onto the SD card I finally got it to boot.

And it hit me – this is Debian – which means all I need now are a long Ethernet cord, got the keyboard and mouse on it already and the power – get this, the front of my Motorola Cable box has a USB port on it. So I plugged into that and lo and behold, it puts +5V and GND out! Yay!
And it got me to thinking. Right now I’ve only got an 8GB card in there. But people have used 32GB and 64GB cards. I can use RasPi for the wireless MESH I’m putting together. I’d have to get a USB hub so I can create a second network adapter but one of these little RasPi’s could be the SquidProxy and DansGuardian server. All solid state, nothing to really wear out. And it costs $35, with the external net adapter it goes to maybe $55. That isn’t bad – < $100 and you can just flash the whole thing on an SD card.
Very cool!


Another way to flash an OS onto your Raspberry Pi SD card

So since my last post I found out dd did not want to place nicely. I had thought about booting the computer with a Knoppix disc but meh, pain. I also downloaded win32diskimager – piece of shit. It didn’t even see the SD card.

So finally I did some searching. First I found this disk erase tool and wiped the SD card clean.
Then I downloaded another nice program called Flashnul.

Once you’ve got flashnul installed execute the following, though the path to your image file may vary:

flashnul F -L L:\2012-09-18-wheezy-raspbian\2012-09-18-wheezy-raspbian.img
And off you go. Mine is flashing it onto the SD card now. Taking awhile but it works! The -L option means LOAD. So I told it flashnul F – that’s the drive I want the image loaded onto, in this case F: in windows parlance. That path that starts with L:\  – that’s where my source file lives.






Stuffing an image file onto an SD card for the Raspberry Pi

Well – it isn’t so easy on Windows of any flavor. Microsoft in their wisdom uses a fucked way of referencing devices.

First I had to find a program to wipe the SD card. A little application called appropriately, DiskErase to the rescue.

Then, because I needed a way to stuff the image, I found a windows version of the popular Linux tool ‘dd’ = disk dump. But not just disks but files too.

Now I’m used to doing it this way:

dd bs=1M if=/dev/sda0/home/tonypo/file.txt of=tonypo.img and it’s done.

But on windows dd instead of using ‘of’ (output file, if is input file) you have to use od (output device)

So in my case it’d be:

dd if=2012-09-18-wheezy-raspbian.img od=F:

F: is my SD card. So with that in mind I can now successfully flash images to an SD card. Yippee!

My Raspberry Pi has arrived

So I checked the mail today and there was a little box from Allied Electronics. What could it be?

Opened it up and there it was, the Raspberry Pi Model B. The different between the Model A and B is that the latter has dual USB ports.

Raspberry Pi Board

It’s a wild little platform! It’s name was derived as follows:

First – a lot of computers in UK were named after fruit, in fact computers and music players in the U.S. are made by Apple. So they chose the name Raspberry.

The Pi part is a morph of Python which is the programming language it understands.

I’ve got to order an SD card with decent capacity for it, I can get a 32GB for $18.99 – not bad!

I do have a 2GB SD card in my camera that I could wipe and replace. I also have an 8GB micro SD in my wallet and I have the adapter for full size so maybe I’ll use that in the interim.

But it’s finally here. It will probably see light sometimes this week. Been kind of busy.

But the Raspberry Pi specs:

Broadcom BCM2835 SoC
ARM1176JZF-S 700 MHz emulated
Dual USB and 10/100 Ethernet
HDMI Out supports 1080p
RCA Composite Out

Pretty wild little computer.

Programming Computers – and why we’re failing miserably

In preparation for receiving my Raspberry Pi I downloaded the Raspberry Pi User Guide from Amazon by Eben Upton and Gareth Halfacree.

In the introductory chapter Upton makes an observation that I too have seen in the past. The computers we use today, many of us don’t use them to their full potential.

I saw this doing Program Reviews for the RI Department of Education a few years ago. In one class they were using Excel to do a payroll sheet. The teacher had them using a paper look-up to calculate the tax.

This prompted me to ask the teacher if they had any plans to teach them about VBA, a fairly powerful little tool inherent in Microsoft Office since day one. And it hews to BASIC, a language that if you took any computer class, you more than likely have a passing knowledge of it.

With that you could have a module that auto-calculates the tax and other deductions. The teachers answer was that you needed advanced math to program a computer. Granted, when compared to some others I did get a bit more advanced mathematics training for my I.S. degree but out of all of it the most used is some algebraic functions. So on my review I put that they should introduce students to programming using Microsoft VBA that is included with Word, Excel, PowerPoint, Access, and even Outlook!

In my career I’ve done extensive VBA in Word, Excel, Access and Outlook. In Word it was to do automatic document conversions from WordPerfect, in Excel it was normalizing data such as fixing short UPC codes, etc. and in Outlook it was a routine to scan the body of a message looking for a specific indicator, then forward the message to a pre-determined route. This is what allowed police department in RI to run a suspects fingerprints and receive positive identification if the subject had prior contact with the criminal justice system.

That’s the power of VBA.

And if kids knew that – and perhaps some Python there’s no end to what we might see.