keith
I collected roughly 1,000 index pulses from the Sony MPF920-E with one common floppy inserted. The motor speed variation was very very small. I am impressed as to the accuracy. Across 967 index pulses, all were within...
on recent disk reading results
(this was posted to Classic Computer mailing list, please disregard if you’re on the list. I think this is an important topic) The last two nights I’ve been busy archiving some of my Amiga floppy collection...
New demo video for the FPGA version of the AFP!
New demo video for the FPGA version of the AFP!
Enjoy!
(45mb download warning)
FPGA implementation of AFP demo
New pictures for FPGA AFP
Here are some new photos for the FPGA version of the AFP.
Click for full size.
Enjoy!
more real world tests
So tonight, I put my new FPGA implementation of the amiga floppy project to good use. I read some more of my collection of amiga floppies. GREAT NEWS. It’s working like a champ. As a matter of fact, I selected...
found bug last night
With this new FPGA solution, certain tracks would result in what I call a “short read.” A short read is any received track that contains less than 28,125 delta T’s, aka pulse times. Given a certain...
re-examining XOR data checksum used on amiga floppies
So I was wondering exactly how effective the XOR checksum that Commodore used for the amiga sectors was. If I read a sector, and perform the checksum, and the checksum matches the stored checksum, then the data is the...
characterizing speed performance of floppy drive controller
So I’ve got things working rather swimmingly right now. Switched drives from Samsung to Sony, and it’s made a huge difference. The Sony just seems to work better. I’m averaging about 355ms per track...
working FPGA version of the amiga floppy project
So, I’ve been working on the FPGA version of the amiga floppy project for some time. I just recently had a fair bit of free time, and so everything came together rather quickly! I’m now able to read amiga...
created testbench for state machine / block ram tester
So tonight I fooled around with ISIM, which is Xilinx’s simulator. I was doing behavior simulation and wrote a small testbench for the block ram state machine that I wrote a few days ago. Really neat stuff...
finally got some memory working on the FPGA
So since I first picked up this Xilinx Spartan-3E starter kit evaluation board, I’ve been trying to get some memory working on the FPGA. The DDR is as elusive as beast as I can find. I’ve not yet given up...
SX EOL
I hate when this happens. 🙂 The Parallax SX microcontroller line has reached production EOL. The owner of the SX design (www.ubicom.com) has given Parallax final notice that we are to place a lifetime buy of wafers. We...
Histogram of one track
Here’s a histogram of one track off an amiga floppy disk. Notice the peaks near 4us, 6us, and 8us. I’ve got this data from my logic analyzer, crunched through my little C proggie, and then graphed with...
bought a Saleae Logic. Another tool for my toolbox
I bought at Saleae Logic which is an inexpensive logic analyzer. See link here. It isn’t nearly as fast (only samples at 24mhz max), and it doesn’t have as advanced triggering capabilities, but it does do...
Finally had some luck with FPGA board
So I bought an FPGA eval board and a book on Verilog awhile back. I made some progress learning things, and had some simple things like UARTs, writing to the LCD, and even some small VGA software(hrrrm, maybe I should...
got build environment working again, fixed uart code
So awhile ago I bought a quad core machine which runs Vista 64. Once I had the new machine, I tried getting my build environment for the AFP working again. NetBeans, the java IDE I use, has 64-bit support but there...
my checksum algorithm
So I’m using an XOR checksum to detect errors in the transfer between the SX and the PC. I always thought it was a reasonably strong checksum, even though it’s still an 8 bit checksum. I found a neat...
sanding a 556 timer IC to expose the die
So tonight, just for the fun of it, I decided to sand, by hand, a 556 timer IC. I just bought an extremely inexpensive microscope and was very interested to see what pictures I could get from it. Unfortunately, for me...
