Retromaster’s Electronics Projects

…related to old computers and other assorted stuff…

Archive for February, 2011

Cumulus Page Up!

Posted by retromaster on February 8, 2011

First of all, the Cumulus project now has a home page  :).

I’ve made a couple of important updates to the Cumulus firmware. First, I made sure that support for both Epson and Phillips LCD controllers is in place and working well (Nokia 6610 LCDs come mainly in these two flavors, as is well known now). There are a few relevant differences between the controllers, mostly in initialization of the controller and handling of screen orientation.

I also implemented bootloader support (i.e. SD card firmware update). It proved to be a little trickier than I first thought, mostly due to compiler issues and a misleading example from Microchip. The main issue was that the compiler does not actually load the table pointer for the erase operation unless you actually issue a dummy read operation first. Now it all seems to be working fine. Right now, the bootloader is larger than it needs to be (there is an embedded font I used for printing debugging messages on the LCD) and verification is missing but these are easy to fix and finalize (before a binary firmware release is made).

I’ve also populated one of the CumuluBus boards that I received and I am glad to say that it works fine.

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Quick Cumulus Update

Posted by retromaster on February 1, 2011

Here is a small update on what’s going on with Cumulus: I’ve finally received the CumuluBus boards from the PCB manufacturer today. Within the next few days, I am going to assemble and test a few of them, and if all goes well, move on to assembling some full Cumulus boards.

The source code for the Cumulus firmware has been available at the defence-force SVN for some days now:
http://miniserve.defence-force.org/svn/public/oric/hardware/cumulus/.

I have not worked on the sources after I uploaded the sources though, mainly because I have been working on (yet) another, quite different project during the last week or so, while waiting for the boards. I’ll disclose the details about that soon here on the blog.

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