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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new design on SX software

Welp, I’m having trouble tweaking my existing SX code. If I modify the timing of the current code, I’m getting all garbage output — even adjusting small amounts to one side or the other, produces much...

MFMSanityCheck

While I’m hesitant to post this at all, this is a quick and dirty application I threw together, and I do mean threw, that will check for valid MFM bytes. See the previous post for the link to the actual bytes. It...

new design

I took David’s advice, and I rewrote the code last night. Some highlights: 1. ISR is entirely in assembly. Although I haven’t manually counted, it appears to be about 400ns in length. 2. ISR triggers only...

today’s successes

I really stumbled on some stuff, and I think I have traction on a couple of problems. 1. My sizes are absolutely perfect. For me, this is a big milestone. This tells me alot. I’m getting perfect distances between...

Good news. Floppy now under SX control

OK, so I finally bit the bullet and have the floppy drive under direct SX control. I have my amiga power supply, which is a modified PC supply with harddrive leads powering the drive directly with +12v and +5v.  I also...

feasability of writing disks

While there are some other bug fixes and documentation to be done on what’s already been implemented, I started thinking about writing ADF’s to disk over the last few days. While the hardware part of it is...

Logicport screenshots and project file

I thought this might be neat to put up. Sorry about the high-res image but you lose too much when it compresses it. Click here for the screenshot. Also, I uploaded the .LPF project file which can be viewed for free with...

new book

I recently received “On the Edge: the Spectacular Rise and Fall of Commodore” and have read about half of the book so far.  Very interesting read.  It’s fun to read about how the various Commodores...

writing merged USB comm code

Now that I have USB receive working in the main PC code, its time to merge the USB transmit(and receive for commands) into the main SX code. I have two pseudo-code versions written. 1> First version uses the ISR to...