Welcome to Arbadell Blog
November 11, 2001: I felt I've got enough stuff to start a web page so
others can see my development as it progresses. As of today the CPU
implementation is nearly finished. I expect it to be done by next week.
The chipset is well underway and should be finished in three weeks. The
loader will be done in about two weeks.
November 15, 2001: I have finished to code for the CPU. It is
written in Verilog and I will post the state machine for the Control
Module as soon as I can get it scanned in.
November 20, 2001: I've posted the tif files of the CPU
architecture, Arbadell system architecture, and the control logic state
machine. Now working on loader and assembler.
November 28, 2001: I've finished the assembler and have posted
it on the page. Ellie is almost done with the chipset. I'm very deep
into coding the loader. Should be done with that in a week or so.
November 30, 2001: Finished the loader. I now need to find an
FGPA to put my CPU design on. Then I can start wiring it up on a
breadboard and debug it.
January 1, 2002: Apparently the holidays are a bad time to try
and get things done. At this moment I have just got around to wiring
the project up on a perf board. I'm also looking at free schematic
capture programs. I need to get my butt in gear.
January 17,2002: Just finished the schematics and posted them
on the site. I've got all the sockets and discrete components glued
down to my perf board. All that's left to do now is start wrapping it.
August 9, 2002: I got a job in January with a company named
Logic-Plus designing an FPGA thanks to Arbadell. The job lasted six
months. I am now unemployed an so I have begun work again on Arbadell.
I have just finished the simulator written in Java and posted it on the
web page.
October 23, 2002: Believe it or not I've got Arbadell running
(barely) on a breadboard. I've spent the last couple of weeks wiring it
up. The biggest challenge was loading the FPGA. I found a way to load
it using an 8-bit parallel EPROM. I just updated a bunch of the
documentation. I really need to draw a new schematic and will begin
looking for a free schematic tool on the web and will post the new
schematic when I'm done.
October 30, 2002: I decided to use Eagle as a schematic tool.
They have a limited freeware version available. I managed to create the
new schematics and get them posted here on the page. I had to download
the Xilinx library from the Eagle page. Also, the windows version of
the software has a terrible memory link. It eventually becomes unusable
after 30 min or so (sometimes less). I would recommend trying it in
Linux next time.
November 2, 2002: Eagle is capable of creating a board file
from the schematics. I managed to get it to work and have posted the
.brd file.
November 5, 2002: WOW! Today is a great day. Arbadell is
working and functional. I just finished spending the day verifying
Arbadell and believe or not she works. There is still some work to do.
Dorihel needs to handle shift-letters, switching to no load sometimes
causes a short somewhere, there is no battery backup to the CMOS, and
there is no VGA. I think I will get a preliminary board and test
everything. After that I will fix all problems just mentioned. I
thinking of just scrapping the VGA.
November 21, 2002: I'm going ahead with VGA development. I'm
going to use a PIC, CPLD, and some latches to do the job. As far as
battery backed CMOS I plan to use NVSRAM. I will cost a little more but
is exactly what I'm looking for. Found the short and fixed it. Also, I
was able to get boards for free from pcbexpress.com. Thanks a million
to them. I am currently waiting for the parts to arrive. As soon as
they come I'll solder them down and see if everything works. As long as
it does I'll continue working on VGA. I'm currently updating all
documentation. Especially, the basic architecture and state machine
docs.
November 27, 2002: I've updated and posted all the
documentation. The parts arrived and I soldered them down. I found a
few bugs that will be fixed on the next board but it works. I also
found a big bug in the Verilog code (startup block) and fixed/posted
that. So far, all I've tested is the latch but for that to work
everything had to be communicating. I'll test the rest when I get back
from Thanksgiving. If it all works then I will continue VGA development
and try to get another board before the end of the year. I'm going to
post some pics in the next couple of days. Should be fun to see.
December 3, 2002: I've finished verifying the board. I am
satisfied with the results and have a nice list of bug fixes for the
next board. I will continue with VGA development starting tomorrow.
I've updated and posted all code fixes (a couple in Verilog and one for
the assembler). As promised there are also some pics on the page.
December 16, 2002: I decided to postpone the VGA development
to get a new board made before the end of the calendar year. So, I
added the hardware needed for VGA development to the schematics and
board and had them made. I've just finished soldering down all the
sockets, ICs, and discrete components. I'll verify that the old stuff
works first before I begin VGA development. I'll start after tomorrow
(final in CMPE240). After that it's Arbadell until after Christmas.
December 19, 2002: I've verified the older portions of the
board and moved on to the VGA development. Today I was able to use the
CPLD to make an image on the screen.
December 29, 2002: I've found a few fixes for the board. I
have been able to get the code for the PIC video interface written and
working. I've been able to clear the screen and write happy faces. The
only think left is to create bitmaps for the characters and then
Arbadell will be complete. I think I will just do lower case letters,
return, spaces, and numbers. I also think I'll keep the smiley faces.
January 2, 2003: The end is in sight. I made some hardware
changes to the board. It will allow for faster clearing of the screen
and the video PIC will reset the CPLD. I've made the changes in the
schematic and board. The board was sent off last night to be made. It
will have a solder mask and silkscreen. All the needed parts were
ordered last night as well. All that is left is to create the bitmaps
for letters and Arbadell will be complete.
January 7, 2003: I've finished the VGA portion of Arbadell and
posted a nice little pic of it on the main page. I spent some
additional time on the assembler and it is now much more robust. The
parts for the new board have already come in. All that's left is for
the new board itself to arrive. I think I'm going to spend a little
time on the chipset so that it can handle shifts. At this point
Arbadell could easily be used in a demo of some sort. All functions are
in place. All that is left is to fine tune and make additions as
wanted.
January 10, 2003: I've enhanced the chipset to handle shifts
now. Also, you can leave the keyboard plugged in during powerup without
an additional reset. That fix took a couple of days. The new boards
arrived and they are beautiful. I've placed an order for NVSRAM chips
for the main memory. I think I will confirm that they work in Arbadell
and since I have shifts now I think I'll add capital letters to the
VGA. After that I am done.
January 18, 2003: I added capitals to the VGA portion. There
was a lot work to be done there. First I had LIFO instead of FIFO. But
as time and my patients wore on I scrapped the whole FIFO idea and when
there is a request to write the character the PIC uses the clearing
signal and writes it. There is no bus conflicts and the user doesn't
notice any difference. There was one bug in the main CPU that didn't
allow braz instructions to work properly and that was fixed. Also,
after I mucked with the Eagle libraries for the power connector I
screwed up the pinout. So, there is a small board fix needed. Also, I
noticed a small assembler error. I can fix the latter two in about an
hour and I'll try to squeeze it in the weekend.
January 22, 2003: I made the last two fixes and posted all
updated material on the web page. I think I'm going to encase Arbadell
and put her somewhere I can see her on a daily basis. It will make me
feel good when I get down about not finding a job. I'm going to try and
get a snapshot of the web page on a CD. School begins tomorrow and I
need to get started on Roborodentia. As of now I am officially done
with Arbadell and this will be probably be the last entry in the blog.
Wish me luck.