Posted on

Facit 4070 paper tape punching with Arduino mega

A couple of months ago, I had a request from a friend to produce a paper tape as an RSVP to a wedding invitation that he’d received on floppy disk. I dug out my old Facit 4070 in my collection and set to seeing if I could interface it with something modern. This blog post chronicles the results.

Connection from Facit 4070 to Arduino Mega for code:

Facit 4070 D -> Arduino Mega Pin
1 -> A8
2 -> A9
3 -> A10
4 -> A11
5 -> A12
6 -> A13
7 -> A14
8 -> A15
9 -> D9
10 -> D10
11 -> D11
12 -> D12
25 -> GND

I didn’t actually use pin 12 (Punch Ready) in the end, as it was proving unreliable, so I just used timings – a quick and dirty solution was all that was needed, and eventually it proved robust enough with delays in sending the data.

The code was written to take commands from a menu system to set up the arduino and then punch data.  The menu is as below:

Facit 4070 printer arduino interface
====================================
? - show this information
a - punch message in ascii
b - punch message in EIA code
c - clear message
d - display message
e - punch message in ebcdic (no parity)
f - advance tape 10 spaces and punch feed holes
h - punch message human readable
m - enter message
o - toggle odd or even parity
p - turn on/off parity
s - advance tape 10 spaces
v - show version information

To use it, you send an ‘m’ followed by your message.  You then can select if you want parity or not, and odd or even parity if you’re using ascii.  Following that, you can send an ‘a’, ‘b’, ‘e’ or ‘h’ depending on what character encoding you want to use.

 

 

Photo gallery of Facit 4070 project

Github repository of Arduino code to drive Facit 4070

Video on Facebook of the punch working

Posted on

Equality and Diversity more important than education?

Today I checked my pigeonhole to find a certificate in there to recognize that I had attended an afternoon sitting in a lecture theater being told about Equality and Diversity.  Great, but this thing is nicer than either of the degree certificates that I also received from the same institution, and I didn’t have to sit any exams for this one.

I sincerely hope that the quality of the certificates doesn’t represent the weight that is given to the qualification, oh and the fact that this “course” was a compulsory requirement as an employee makes it even more amusing, surely a simple tick on the staff record would have sufficed, rather than the expense of producing these for all staff when we’re being told to save £11M over the next 2 years!

Posted on

Stuff from FOSDEM

What I saw of FOSDEM this year was great, I didn’t see very much because I’m now on staff so have lots of responsibility during the weekend. I did manage to see some lightning talks whilst moderating the room though.

LibrePlan is pretty amazing for a piece of free software from what I can see – it’s a project management suite for a whole company which runs on the web.

PMD5 (catchy name) is a static code analysis tool, which can help keep on top of good practice and good coding style.

Wazaabi is a nice implementation of separating the parts of a UI from the rest of the program. It has an interctive editor that produces XML descriptions of the UI that then get loaded and generated at runtime.

David Fetter made some good points in Threat Modelling Revisited, but I’m not sure how much impact it can make on society – but we can at least adopt them at grass roots level and hope that they filter up.

Mike Sheldon gave an extremely good talk on gnu.fm and libre.fm

I was interested in the talk on Open Remote as I’m rather into home automation.

MuseScore looked very interesting from their stand, and although I didn’t see the talk, AudiVeris looks like it should work with it well.

Overall a great conference again, and I’m looking forward to the post-mortem for this one and the planning for next year already.

Posted on

On “Reflections on Trusting Trust”

In 1984, Ken Thompson wrote “Reflections on Trusting Trust”, and it is still valid today.

All students writing anything higher level than machine code (does anyone still do that?) should have an appreciation of what goes on at various points in the toolchain, and how it can be exploited at each of those levels.

The article can be read here and is also has some refelections on Open Source to consider.

Obfuscation can happen at many levels and nobody’s commits should be taken at face value – only vigilance in code reviews will keep everyone honest.

Oh, and apparently he implemented it, but never distributed the compiler.

Posted on

A short video

For those of you wondering what FOSDEM is all about, here’s a short video that explains a little…

It’s a relaxing look back at what was a very hectic conference for me, so it is interesting to get a different view.

Oh and Aber Comp Sci students feature in it too…

Posted on

Possible backdoors in NetBSD IPSEC stack?

I just picked this up from a friend at the FSFE.

Apparently, someone who was working with the FBI a few years ago alleges that he came across information regarding backdoors that had been inserted into the IPSEC stack.

I know, that this is technical but it comes down to the fact that the FBI can snoop on “secure communications” that are encrypted using the NetBSD IPSEC stack. Now is the time for a code review, especially as it appears that the FBI have apparently been pushing use of the allegedly backdoored stack for firewalls and VPN tunnels.

The email that details this is linked below:
http://marc.info/?l=openbsd-tech&m=129236621626462&w=2

I do like the “Merry Christmas” at the end.

Posted on

Spam filtering, and how not to do it.

Alun is not having a very fun time with secureserver.net and from the sounds of their technical support staff, they’re secure through a certain amount of incompetence.

I’m sure that you will enjoy reading the exploits of a sys-admin at a UK university, so here’s the link secureserver spam blog entry

Oh, and this counts as a little assistance in getting pushed up the google search rankings