Recent content by hackerb9

Old means obsolete but not forgotten, right? So, how do I get access to CT4170.zip which was posted on the Vintage Computer Forum in this thread from 2013? I've given up finding an 8-bit Sound Blaster at a reasonable price and was hoping a 16-bit SoundBlaster PNP config program like the one...

@Radix That's super nifty! Can you share your demo files with us? How about the SVG → ReGIS parser?

Good point. I've stopped the initial test as there's no point wearing out the hardware since the etched ring that's showing up is on a track not reachable by the head. Most sources online say it's not possible, but it turns out you can do it if you're willing to grossly abuse the machine...

Surprising results! I've run the test for 24 hours using the new synthetic felt pad and there is definitely a dark band on the diskette on the side facing the felt pad (the side labeled "B", but technically it stores the data for side A). A lighter ring has also shown up on the opposite side, so...

Good point. So, I just took apart an Apple Disk ][ drive (which is basically a Shugart SA-400) and examined the original felt pad under a microscope. I was quite surprised to see that it appears to be synthetic! A flame test of a few fibers seems to confirm it, though they melted so quickly it...

I'm glad you mentioned this. Apparently "craft felt" is made of plastic fibers and is much cheaper than "wool felt", but I believe a flame test should be able to distinguish the materials. In the picture below, the ball on the left was what I thought was "F1 industrial felt" (>95% wool), but the...

Thank you to everybody who responded to this thread with helpful suggestions. I think my main takeaways are "don't sweat it too much" and "industrial F1 felt will be fine (probably)." Thanks go especially to the kind members here who have sent me parts so I can try to fix my drive. I'm sure it...

This is probably the right answer, though a bit late for me. You'd not believe how deep the tribology rabbit hole goes down. Actually, the problem is not the ceramic part of the head but the gap. I found a paper that mentioned that one of the metals used actually developed an indentation...

Good call on checking for melting point. It looks like if I use F1 "industrial felt" it is made of 95% wool. Doesn't "polishing" imply the Dremel felt is designed to remove material? I'm particularly concerned about two sided "flippy" disks that have a magnetic surface that could be polished...

This is the kind of experience I'm looking for! How many years have they run without issue? How did you test that it wasn't scraping off the magnetic coating on the flip side or causing any other problems? Did you try Shugart's minimum of being able to run 7 days straight on a single track? How...

Thanks for the tip. I'll take a look, but I suspect that those swabs are not meant to last very long.

I could use some help from the disk drive experts here. I am replacing a pressure pad (AKA "load pad") that is missing on a Shugart SA-400, but my question is in general about any single-sided disk drive: How much do I need to sweat the pressure pad details to not cause damage to disks...

It would be great to have an actual Wikipedia page which covered the VT640 (and clones), but it feels like there are a lot of unanswered questions. Since it was sold both as its own terminal (as with the Synclavier) and as an add-on board with specific graphics capabilities, the VT640 entry...

Hi Roland, I had collected some links for a stub Wikipedia article for the VT640, but never created it as it seemed nobody had reliable sources of information about them at the time. It's great that there are now people who will be able to experiment...

So, my IBM 5155's screen started pulsating at me (larger, smaller, larger, smaller) and I'm pretty sure I recognize the syndrome from my MacPlus: the flyback transformer is about to blow. I seem to recall hearing "life hack" tips like, "Stick epoxy on the outside" to keep a flyback transformer...