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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LCD Test image and pixel-level detail

So I’ve managed to get a semi-working test pattern image up on the LCD. Here are a couple shots: If we zoom in about 10 times, we can see how the LCD really works, on an individual pixel level: Pretty challenging...

motor speed variation tests

I collected roughly 1,000 index pulses from the Sony MPF920-E with one common floppy inserted. The motor speed variation was very very small.  I am impressed as to the accuracy. Across 967 index pulses, all were within...

PCBs have arrived!

Just in time for Christmas, the PCBs have arrived from China.  I used Seeed Studio (Fusion PCB Service) and they look pretty good.  Here’s the first look at them. I’m just about to solder one up, so wish me...

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...

sanding a 556 timer IC to expose the die

So tonight, just for the fun of it, I decided to sand, by hand, a 556 timer IC. I just bought an extremely inexpensive microscope and was very interested to see what pictures I could get from it. Unfortunately, for me...

Getting closer….

So a few versions later, trying some different failed attempts, I am finally starting to get a little closer.  Here’s the best video I’ve got so far, but my image is still scrolling. If I can fix the...