keith
I haven’t spent much time within the last few days on the project. Looking at the data on the PC, I think that there are still some problems. I think the problems lie in the fact that the interface to the parallel...
Timing problems still?
I think I’m still having timing related issues. I have RTCC overflowing every 1.8us which I *know* is less than the 2us bit cell(or less than half the bit cell, if you take it to be 4us), but this seems to be what...
Timing image
I just wanted to throw this up here to show an example of how the timing is working on my project. Its working well. Top line is the input signal from the drive. Bottom line is the firing of interrupts, either from the...
PC xfer working now, timing in order
Welp I pretty much solved the big problems I encountered over the past couple weeks. Ground issues — turned out I was attaching ground of one interface to Vdd on another interface. That was solved by actually...
PC xfer still not working
Well I completely rewrote the code. And surprisingly, it looks pretty similar to what I did before. I moved the store/transfer routine out of (being called from) the ISR to the main loop. As soon as the ISR detects a...
Of timing, and general progress
I’ve determined that programming is like whack-a-mole(only took me 15 years to figure this out!) Fix one problem, and another one that already works stops working. This is what happened to me yesterday. My ISR...
making progress on the MFM hardware decoding
The whole question I’ve had for the last couple days (and potentially the last couple months) is how do you turn the signal coming out of the floppy drive into 0’s and 1’s. This really isn’t MFM...
Am I reading MFM wrong?
I’m beginning to think that I don’t fully understand the signalling coming out of the drive. I understand the concepts behind MFM (I think), but the actual application to this project, I’m not so sure...
Schmitt Trigger
Welp, after talking with some smart guys on forums.parallax.com, it looks like the Schmitt Trigger feature on the SX is going to allow me to get rid of my 74HC132 that I’ve spent at least a couple hours messing...
Ground issues
Although I’ve been attempting to have a common ground for this whole project — I’m not sure that is going to happen. At least not at this stage of the game. I tried connecting the ground off the floppy...
SX microcontroller with 74HC132
Here’s a picture of the prototype coming together. From the top down on the breadboard, you see a pull-up resistor, on the input that comes in on the yellow wire. The output comes out of the grey wire on the right...
Using a 74HC132E to square up the wave
A nice gentleman from sci.electronics.* newgroup suggested I use a 74HC132 on his web page here.[local copy] Below is the result of using this design, it worked perfectly. Only required one IC, one resistor, and one...
Current status updated
Current status updated I was originally going to use a Microchip PIC, but they are just too darn slow. I gave up on the idea of using the PIC as a one-chip solution, and tried to use it as just a clock generator feeding...
