Home example 2 – Page 23 – techtravels.org

Amiga Floppy

inital results on error correction

While I have yet to actually implement the full-scale error correction as I want to, I did some manual tests today. I basically took a track that I was erroring out on, and swapped in 1-bit away values for the bad bytes. In some cases, it appeared...

keith

4 comments

Latest articles

Amiga Floppy

SX problem is double-ones, ISR code & description

While I shouldn’t be surprised, my SX hardware issue is related to double one’s, where the SX sees transitions back to back, and writes back to back 1’s into memory. This is assuming there aren’t...

40 views

A501 Replacement Inactive

Found problems with incorrect footprints used for some chips

So I received all of the SMT parts today, and attempted to verify that I’ve used the right footprints for the parts. This was a worthwhile effort because I found a few different problems. Also, digi-key shipped me...

40 views

Amiga Floppy

Parallax USR2SER

So I got my Parallax USR2SER in yesterday. Man is this thing tiny!! About the same width of my finger, and about 1/3 the length! And its mostly surface mount stuff….. It works like a charm. Easy installation, I...

39 views

Amiga Floppy

memory chip mounted

Welp, I got impatient, and went to Radio Shack to buy their soldering station. I still have mine coming in the mail, but its ground from Arizona, which may as well be ground from Alaska. I soldered the header pins onto...

39 views

Amiga Floppy

minor success at 2:00am

well I’ve got MFM flowing from the PC drive now. A couple of things: Pins 10 and 14, the pins I’ve been using since last night, appear to be correct. Pin 10 is the motor lead. Dropping a corresponding SX...

39 views

Amiga Floppy

new pictures

As you can see above, we have a “10” (4 us), another “10”(4 us) and a “1000”(8 us) chunks of data. Little noisy there.

39 views

Amiga Floppy

looking at the code this a.m.

Welp, I decided to take a look at my code today, although I can’t actually implement anything until after I get home from work. 🙂 Not sure if I mentioned this eariler, but I’m now padding the data sent from...

39 views

Amiga Floppy

On speed optimization

The theoretical limit, assuming 300rpm drives, is 200ms per track. Or 400ms per cylinder, or 32 seconds per disk. Most attempts read slightly more than one track. I read 16,384 bytes, or 262ms worth. Right now, if I...

39 views

Amiga Floppy

first day back

You know, I always hate the “first day back” working on a project. Things always seem to get screwed up between the time I last worked on a project, and that day. Even if nothing has changed. Or so I say...

39 views

Amiga Floppy

USB uart send and receive

Good news, good news. After banging my head on the same problem for the last three hours, I’ve finally made some more progress. Using option #2 from the previous post, I’ve written two non-isr based software...

38 views