Recent content by davidpen

There is a new entry in my Gentle Model Railroads blog - Wiring is in place.

There is a new entry in my Gentle Model Railroads blog - 1st run of Amtrak 737

The link works for me but try this http://www.gmrblog.co.uk.

There is a new entry in my Gentle Model Railroad blog - Putting in the wiring busses. Check it out.

There is a new update on my Gentle Model Railroad blog. Here I describe my process in getting the boards made for the new HO layout. Check out my first attempt at stop framing!

Here is the current iteration of the HO Switching layout that I am going to build.

Hi everyone. Not been around for a few years since I lost my hobby room when my mother-in-law came to stay (she is 97!). Having struggled to get a few layouts going, I have finally settled on a 7' long HO switching layout. If you would like to see all of my history - it goes back to 2009 -...

"Empty box cars come from the general pool so can be sourced from either end of the railroad". This includes reefers. "The problem I see with this is that if you have the engine proposing a higher demand than there are cars available, the owner will never know he is short of cars, and...

This is how it works. I was just explaining to the previous poster how my software looked like his pseudo code. My blog at https://tm470routingproject.blog explains: "the DE has to track through every location that could source or require a car and assess any need. Once this analysis is done...

Industry X -> Car Type A When Industry X Needs Random(number) Cars -> Create Train When Create Train ADD Car type (Industry X.CarType) I write in Smalltalk and in pseudo code that comes out as: Car Type A sendTo: IndustryX; [IndustryX needsRandomCars(aNumber)] ifTrue:[ CreateTrain...

I think that you are thinking about traditional databases. The only thing that matters in this scenario is "this train". The system builds the train for you. You use the information; tell the system that you have moved all of the items; the system updates for the new locations and then that...

Only if you are using it as though it was a SQL db (which would be pointless). KV databases are used for fast access by keys - not by searching. There are objects in buckets accessed by keys. You use it by dumping and reading complete records ( not an expression that I like - I prefer...

Not using a SQL database. On a Key/Value database, there isn't any normalising. You have multiple copies of data under different keys. Using an example of my model shop web data base: key -> Value SaleID -> sale record. Client Name -> sale record list Client ID -> sale record list and so on...

I am busy working away on the project. Although it is, supposedly, a software project, the University sees it as a project report. I am expecting to have a working prototype to accord to the the original design once the course ends but the University deliverable is a 10,000 word report. To help...

I have been model railroading since the mid-50s but almost never had a fully working layout. Something always gets in the way. As I am now retired and building a railroad "properly" my wife demanded(!!) that I have some people:-) To stop the trouble, I not only have people but I also have cows!