techtravels.org

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...

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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...

more testing

so I put the amiga floppy back on the amiga, and the amiga reads disks no problem.  Glad to see that my drive hadn’t fried through all my messing around. I haven’t seen valid MFM coming from the drive in so...

even first or odd?

Despite having a couple different official sources, both AFR.c and floppy.c from the fellow amiga emulator says that the even bits come before the odd bits. This is true in the sector header decoding as well as in the...

Changes to the PC side

With more and more things pointing to the PC, I’ve decided to really reduce the amount of work the PC has to do in its receive loop. I looked at Marco’s because his was designed to run (albeit in dos/dos...

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.

Creating more test disks

From both Tim’s suggestions and from a reinforcement from Agans’ Debugging book, Chapter 6, “Divide and Conquer”, they suggest to “Inject Easy-to-Spot Patterns”. And of course, I knew...

new isr thoughts

While this new ISR is indeed easier to understand and much more simple, I can’t help but remember what else my ISR used to do for me. The four things I really lose are: 1> Any type of double 1’s protection...

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...

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...

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...