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...

Latest articles

working cause of bit errors

I think I’ve stumbled on something. I don’t think I’m capturing enough data. 13,824 has been my magic number forever.  It was larger than the 13,800 that Marco used in afr.c.  But I’m beginning...

left-justified DAC problems continue

Here you see the analog sound waveform coming out of the DAC at the top in yellow. I think I’m getting closer……I switched from the I2S DAC to a left-justified DAC just because the LJ one is a little...

problem with high density disks

I’m running into an issue with HD, high density, floppies.  The output on the scope looks just fine, but I get a consistent bad checksum on all the tracks.  I’ve tried with and without covering the HD hole...

Intronix LA1034

I’m seriously looking at the Intronix LA1034 logic analyzer. It’s a USB PC-based logic analyzer.  34 channels, samples up to 500mhz, and has nice trigger options, etc.  I’ve downloaded the software...

ISSI memory chip mounted

So I can’t believe how freakin’ tiny those pins are coming off the memory chip.  The pads on the surfboard were huge by comparison.  I actually thought there was a manufacturing defect on the memory chip and...

added byte-sync to my transfer routine

Well, after much thought, pondering, and discussion with David, I finally implemented a working byte-sync routine to my SX software. I don’t have it fully working with the PC side software yet, because this...

Parts ordered for the A501 replacement card

I placed an order yesterday for some prototyping parts to get this project off the ground. Some of the key parts are: ISSI 256kx16 SRAM chips. IC SRAM 4MBIT 25NS 44TSOP A surfboard to do 44-pin TSOP II to DIP.  Wish me...