cleaned up the project

So after banging my head for awhile, things still aren’t working as they had prior to my stepping away from it.

What I did last night was to partially dissassemble everything, and rewire a decent portion of it.  It is a HECK of a lot cleaner, which means it should be easier to debug, trace lines, etc etc.

My impression of the current problem is that the drive isn’t being properly selected, and as a result, isn’t actually putting out real data.  I had this problem awhile back, but I had fixed it.

I got sick of my office being warmer than the rest of the house, despite full A/C in the house, I installed a room air-conditioner, and its now very comfy.  This required a new circuit be run, and while I had the walls open, I ran an extra circuit for extra capacity.  I now have three different circuits in the same office, one solely for the A/C, the one original to the house, and the new one.

About the author

keith

Amateur Electronics Design Engineer and Hacker

4 Comments

  • Love this blog! I’ve only just found it and have read all your old posts.

    I’m in England. I have an old A1200 in a closet (unexpanded, except for an external floppy drive, but I won’t be hacking with it any time soon). I used transdisk, an LHA compressor, a file splitter and CrossDOS to turn some disks to ADF, but I ran in to problems with the 2MB chip RAM available. Some ADF images would be too big to copy in RAM, and then split. There’s probably a good AmigaDOS way of manipulating a nearly 1MB ADF without using loads of RAM, but I don’t know many commands. I hear there are all-in-one programs on aminet that probably use less RAM to create and split ADF images so I might check that out sometime.

    Anyway, I found Marco’s ‘afr10f.zip’ and got interested in the idea of hooking an Amiga external floppy drive to the parallel port (that’s how I found your blog). I might try and make his interface at some point, but before I would, I’d want to know how the electronics work (be a little crazy of me to make something I wasn’t sure about). Unfortunately, I only have a little electronics knowledge so I’d have to read loads of datasheet PDFs and then study the circuit for ages and ages to get some idea, but I don’t feel like starting that yet.

    I just wanted to myself so I can give some words of encouragement, because the hardware hacking you’re doing is great and entertaining for readers like me.

    There is one thing I think you should beware of. Marco’s ‘README’ file has a ‘Copyright’ section that puts some (very minor) restrictions on his source code. If you ever plan on open-sourcing it, or even just selling it, any of your code you compile with his might become ‘tainted’ by his license (which he says applies to modifications of his code too). So for future planning you might consider a rewrite which is just inspired by his code (same algorithms?).

    Wow I think my reply is longer than your post. That’s probably not a good sign tehe. I’ll stop talking for now.

  • whoops! big mistake in my post

    it should say “I just wanted to *introduce* myself so I can give some words of encouragement, because …”

  • Hi GrimRC!

    Thanks for the words of encouragement — they are sometimes more valuable than you might think.

    After cleaning up the project the last couple days, I have managed to get it back to at least the state it was in before I dissassembled everything. I pulled all the wires and reran everything in a much cleaner and neater style. I also moved around some port assignments to put the entire floppy interface on one PORT, etc.

    I’m still getting trash data from the drive, which I have yet to figure out why. I’ve got to get into it and get my hands dirty again.

    I also moved to a smaller cable, 2ft instead of the 6ft I was using earlier. While I don’t think this is an issue, the amiga specs say 1 meter total for all cable lengths, and I wasn’t sure how much a longer cable might change the value of the pull-up resistor I’m using (currently 1k)

    I’m pretty inexperienced regarding hardware and electronics, despite messing around with little projects for over 15 years. I’ve never really understood what I was doing, simply following schematics, diagrams, etc.

    I’m working on that. I’ve managed to interface to the FRAM memory quite easily, program the SX, and that USB interface (which is pretty much already off-the-shelf ready to go). I’ve managed to “reverse engineer” the hardware format of the data through trial, error, and advice from people smarter than myself. Alot of this stuff isn’t documented, or is documented badly, and there are no real current experts.

    Marco’s work is definitely a stepping stone. I’ve tried endlessly to get ahold of him because I think he’d be interested in what I’m doing. My plan is to eventually do a rewrite of it, potentially in JAVA for cross-platform support.

    I have no real plans to sell this thing, and don’t want to profit from it. If this was a money-making venture, I’ve probably already invested too much time and money into it to make it pay off. If there was enough interest, I might possibly sell an assembled kit or something, more as a convenience to the user than to make a profit for me. This isn’t to say I wouldn’t charge enough to cover basic associated costs…

    I’ve been to England a few times in the last five years. Great place. I’ve spent a fair bit of time in London itself, but I’ve made it as far south as Brighton(edited from Bristol, oops), and as far North as Abderdeen in Scotland. Beautiful countries. While the architecture is certainly different, I’ve often remarked to people here in Pennsylvania how much the English countryside looks like our own land. Very green in parts, rolling hills in others, and so on. I’ve been to Europe several times, and really enjoy the different cultures, peoples, land, food, and so on. Have you been to the US?

    P.S. Beating me on verbosity is a tough challenge!

  • I live in Manchester (some call it the capital city of the north). I like it here, and I am not that well travelled (I’ve only been to France). I’m 24 years old, become unemployed and moved back in to my parents’ house.

    I seem to be hypothyroid (undiagnosed at the moment). I’ve had one blood test so far, but I got patronized by the last doctor so I haven’t been back for my next thyroid hormone blood test (meant to be 3 months after the first). Hypothyroidism is a condition that makes you fatigued and lethargic, and causes lots of other minor complaints, so basically it causes you to be lazy. I’ve started to wonder if there’s any such thing as laziness (is it always subtle illness?).

    Anyway, eventually I will register with the local doctor and get retested. Hopefully, I’ll get diagnosed and be prescribed some thyroxine. Fortunately, my parents will support me at the moment so I don’t have to get a job while I don’t feel well.

    I read a lot on the internet, and have seen some other projects relating to the Amiga & Atari computers (I have an Atari 520STFM and an Amiga 1200). I was wondering about trying uclinux (Linux for MMU-less computers), as someone else has already had some success. Have you heard about it?

    http://users.telenet.be/geertu/Linux/68000/

    I like Linux and GPL software a lot and used to run it exclusively (not right now though; too lazy to install a decent distro on my PC that I can keep up to date easily).

    I was also wondering how feasible it is to rewrite/hack the Kickstart ROM on the Amiga and the TOS ROM on the Atari. There’s a free Atari ROM replacement. I wonder if it could be hacked to run on the Amiga and provide a GEM environment and run Atari ‘GEM-compliant’ programs (no hardware-hitting programs of course).

    I’m just thinking out loudly though really. I won’t be doing much hacking until I install a decent Linux distro on my PC (good hacking environment I think) and get some thyroxine.