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FALCOR4

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Posts posted by FALCOR4

  2. Posted

    If I remember correctly, didn't Mike Wright with PC99 write an article or two on Advanced Diagnostics and Diskassembler on how everything loaded with all the security. I thought he accomplished years ago making a PC99 disk of those programs.

     

    Beery

     

    Would love to see the articles.

  4. Posted · Edited by FALCOR4

     

    Yes, and what did you do in that cases with these bytes? Or could you avoid to write the special bytes?

     

    The WD specs list these special bytes. When they are written into the data register of the controller during a Write Track operation, the following action takes place for FM (MFM has some different values):

     

    00 - F4: Write that byte with normal clock

    F5: not allowed

    F6: not allowed

    F7: Write the two resulting CRC bytes

    F8,F9: Write Deleted Data Mark + preset CRC

    FA,FB: Write DAM + preset CRC

    FC: Write Index Address Mark

    FD: normal

    FE: Write IDAM

    FF: normal

     

    This is one of the reasons why you cannot simply create a track copier based on Read Track / Write Track.

     

    The HDC9234 on the HFDC card offers another implementation of the Read Track / Write Track. In particular, it delivers the contents of all the sectors of the track, but no headers or gaps. The Write Track is a complete track formatter that takes arguments including the sector number sequence, and then creates the track on its own. For that reason it should be impossible to read these disks with a HFDC. It is possible, though, that the BwG and Corcomp controllers can read the disks, since they also use a WD chip.

     

    If I understood correctly what I saw in the Diskassembler loader, the program adapts itself to these controller by inverting some locations in the code because the FD1771 has an inverted data bus.

     

     

    Arrrr, I'm going to try this one more time. I keep losing my posts. We built routines that converted a word of data to two words of ASCII; this got around the problem with writing >F5 - >FF to the controller during track writes. That's probably what we did with the DiskAssembler but until I get all of my hardware back together I won't be able to recreate some of the things we were doing. Working on it. Attached are two subs; the first is from some disk production routines that convert a byte into two chars, the second is from one of the loaders that restores two word of chars into a word of data. Hope that helps.HEX ASCII conversion examples for track writers.txt

    • Like 2

  5. Posted

    Curious, to what circuit/device are you providing the 2.9v? I just want to make sure not to mislead you because what Osgeld and Stuart are saying as a caution are very true. For example, if you ground that node then your 470ohm resistor will have to dissipate .3 watts, that's a worst case scenario. It will be a toasty warm 1/4 watt resistor in that instance.

  7. Posted

    I'm resurrecting this because too many recent things are pushing me back in this direction.

     

    First, the Navarone from Vorticon. I now have that and am planning on studying it closely.

    Next, Shift838 publishing his 2 port version. I lack the skill and knowledge to create my own PCB design for this project and that is what really holds this up. I can't deal with the prototype and all the wires and connections I made while working on this.

     

    Finally, Yesterday's news with a navarone modification article in it.

     

    I think that article brought me back to a moment of confusion that I don't think cleared itself .

     

    I need to know what the pinouts are if you are physically looking into the cart port of your console.

     

    At first i used the image on the left (below) but was told by someone that is how they are on the mainboard but with the 90 degree adaptor in there ofr cart placement, the pins flip vertically. Then I was told by someone else much later that was incorrect and the diagram shows the actual pins as they appear on the 90 degree adaptor, then reading this article it talks about pin 1 being on the right side but I'm unclear if they are talking about the grom port or looking at the card connector from the grom port's perspective.

     

    I just need to know a definitive answer. If I flip the little door open and look inside my console's cartridge port with a flashlight, what pin is the upper most left pin? This is probably why this project stalled out, I'm not getting the pin assignments correct.

     

    attachicon.gifUntitled.png

     

     

    Another check you have is the GramKracker schematic you're reproducing. It's has an "as your looking into the port" set of pin numbers.

    • Like 1

  8. Posted

    Shift838, use the voltage drop across the 470ohm resistor for that calculation and the the node voltage at your takeoff node (2.9v) for the 15ohm resistor. So; (12-2.9)^2 / 470 = .18 watts. (2.9)^2 / 150 = .06 watts. If I did my math correctly. Hope this helps.

  9. Posted · Edited by FALCOR4

     

    Here's what the "raw ASCII" odd tracks look like in the HFE disk explorer. Note that even the HFE explorer can't show you the values because there's no "sector" to look at. Probably why the HxC software is identifying it as an Arburg encoding scheme. According to that web page, "This kind of floppy disks was pretty unreadable, even at the lowest level (using OmniFlop) because of their "tape-like" format, with no sector, no ID, no header, no CRC..."

     

    Falcor, any insight into this? It's rather cool... goes beyond writing a regular sector into writing raw data with no format at all.

    Hi Jon, my honey do list was long this weekend so in the interest of self preservation I've been working it down. So, briefly, I believe that what you're interested in looking for is in the WDS1.DSKASM.BUILD directory. Especially look at the code titled MAIN. If everything is still in there it is part of what should build a DiskAssember disk from the DD1-DD5 files that should be in your FNL041186 directory.

     

    The main piece of information that got us tinkering with the disk formats was after I got a copy of the WD Storage Management Products handbook which has all the technical information for the WD177x, The Write Track function is a TYPE III command and from the book, "Data and gap information are provided by the computer interface" and "Normally whatever data pattern appears in the DATA REGISTER is written onto the disk with a normal clock pattern." The exceptions are patterns of >F5 or >FE which are interpreted as Data Address Marks with missing clocks or CRC generation. So, I just took that as I could write a continuous track with whatever data I wanted to put there and that's more or less what we did. As far as odd sectors, the controller allows 128, 256,512 and 1024 byte sectors so that's why you're seeing 1024 byte sectors as well, with some embellishments.

     

    Change of subject, I saw in an earlier post that someone was upset that they couldn't copy their legally obtained copies of MG products. I mentioned this in an email to you, Jon, but I'll repeat it here as well. Craig and I talked about this type of protection for a long time debating what the reaction might be. It was decided to go ahead with it in the hopes that it would fend off piracy for at least a year. This was Craig'l livelihood. It didn't take that long....and some were rightfully upset over it. In retrospect, we may (I say may) have actually accelerated the proliferation of tools like track readers and hardware that allowed easy access to memory. It definitely sparked interest in some as to how we were doing it.

     

    Sorry, I haven't been able to dig into this deeper for the moment. What I need to do is to duplicate my setup that I had back then to produce these products but I'm missing some hardware at the moment.

     

    Hope this helps

    • Like 5

  11. Posted

    Thank you for the post. I'm sorry to hear that, so many now have gone. He was someone who meant a lot to me. I'm not sure that the Gram Kracker would have ever happened if not for his inspiration....... :(

    • Like 3

  14. Posted

    Hi Matt, I caught this thread today; started at 2016 and just finished. I've been out of the game for over 30 years so I'm trying to get caught up with the help of a couple of good friends. Thank you for all the effort you've put into this project, it really opens up a tremendous number of possibilities. My imagination is already running wild, this is a powerful solution for expanding the old TI99! I'll keep checking in to see when you are at the distro point for your board. Keep up the great work.

    • Like 3
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