Home example 2

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

bought a Saleae Logic. Another tool for my toolbox

I bought at Saleae Logic which is an inexpensive logic analyzer. See link here. It isn’t nearly as fast (only samples at 24mhz max), and it doesn’t have as advanced triggering capabilities, but it does do...

143 views

Badge Computer

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...

143 views

A501 Replacement Inactive

Populated PCB with fix for unneeded inverter

Lots of progress but little time to talk about it. Here’s the fully populated card installed. There were two issues identified so far with the PCB design. One, the battery holder silkscreen was upside...

140 views

Badge Computer

J68 is now booting from User Flash Memory on the BEMICRO MAX10 FPGA board

I’ve been struggling for quite a few nights and weekends over the last month or so. I’ve now successfully attached the J68 to the built-in User Flash Memory. This means that the 16KB (actually about ~13KB)...

137 views

Amiga Floppy

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...

135 views

Badge Computer

Interesting snippet from FPGA Prototyping by Chu

This is exactly the problem that I’ve been facing for the last couple weeks. I could get the memory tests to pass at 100% if only the CPU was talking with the external SRAM. As soon as I added in my time slot...

130 views

Amiga-VSC Inactive

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...

128 views

Amiga Floppy

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...

126 views

Amiga Floppy

first .adf written

Well, I’ve written my first .adf tonight! I threw together a quick routine on the PC side to query the SX for both sides and all the tracks. It generated a 901,120 byte .ADF file of a disk I had called...

125 views

Amiga Floppy Inactive

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...

124 views