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Gorgonops

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Everything posted by Gorgonops

  1. Here it is, and it includes a schematic for fixing the horizontal drive pulse. http://members.optusnet.com.au/eviltim/macmp3/macmp3.htm Again, strictly note that this doesn't solve the 1-bit digital input problem for the video information.
  2. I fudged the horizontal sync pulse and back porch widths slightly from what it says in the devnote because adjusting them to match the specs in that nerdhut article: Made the vertical and horizontal sync frequencies match up with the quoted specs for the monitor exactly when using the specified dot clock rate. (With the calculator you specify the dot clock and the hsync/vsync frequencies are calculated based on the other items you specify.) IE, I made the sync pulse "3" pixels instead of two because the two pixels that *seem* to be specified in the developer notes are only 2/3rds of what's observed by Nerdhut, and I adjusted the back porch down by a few pixels to compensate and make everything else line up. It's very likely the monitor would work fine with either my/nerdhut's settings or the 2/178 that's in the Devnote, so I recommend not obsessing over it. The DevNote's settings make for a pretty short sync pulse and reduce the effective vertical framerate slightly compared to what the published specs say it's "supposed" to be, but only a fraction of a percent. Have you actually worked out the analog pieces you're going to need to make this happen? As I mentioned earlier, the compact mac's driver board doesn't take standard TTL vsync/hsync signals. There's an old article floating around which I'm sure you'll find a link to if you search enough where someone turned a compact Mac into a DOS MP3 player by driving the CRT from a VGA feature connector, I believe that article described the difference between the signals. My only vague recollection was at the very least you'll need an inverter on one of the lines?
  3. I'm kind of confused as to why you're looking in the LC II devnote for anything related to this if your goal is to set up a Compact Mac-compatible display mode? The Compact Mac screen does *not* run at the same scan rates as the 12" 512x384 monitor. If you're serious about trying to pull this off, IE, converting a B&W Mac monitor to run off of a more conventional video card, I have a suggestion for you: put this SuperMac video card out of your head for a while because it's actually a pretty lousy thing to be starting with. Instead of having a programmable timing generator like you'll find on more modern cards it requires swapping oscillators to implement new video modes, and of course is tool to set up said modes isn't by any means a standard thing so you're going to have a lot of trouble finding anyone able to help you translate specs into its lingo. I'd suggest starting with a rotgut PC with a simple VGA card (almost anything will do, ATI cards have always been a good choice from a compatibility perspective), slap Linux or FreeBSD on it, and once you've determined how you're electrically going to interface the VGA card to your compact Mac monitor (an exercise for the reader, remember that in addition to either needing to swap the neck board out or radically hacking the analog board if you want to accept an analog grayscale signal you'll have to add some circuitry to make it accept standard sync signals, that has been discussed in a few other threads) you can try using a standard Modeline calculator to come up with a video mode that works. Based on the values in the "important numbers" box on this page I used this modeline calculator to come up with the following Xfree86 modeline: Modeline "512x342" 15.6672 512 526 529 704 342 342 346 370 -hsync Here's what I input to come up with that; some of the values arrived at by trial-and-error: And here's what the calculator says they add up to: Which looks like a pretty good fit for what we know. Once you have this working with something like a standard video card then perhaps you can figure out how to translate a modeline into what your SuperMac's control panel wants and also know what crystal you need to buy.
  4. Another thing to think about here: regardless of whether or not pulling that little fake declaration ROM off the board in an SE/30 would make it "not see" the display hardware you have to remember that the actual display hardware would be there regardless. IE, there would still be address decoders sitting on the bus enabling the SE/30's VRAM and whatever control ports it presents inside the SE/30's slot area *unless* there is some sort of mux/buffer that has to be explicitly enabled to allow that hardware to work, and the control port for *that* would also likely reside somewhere inside the slot $E area. That stuff is *electrically* going to conflict with any other PDS device you try to put there. The fact that the SE/30 displays "simasimac" instead of a blank screen when it's broken in such a way to prevent it from starting is a clear indication that the hardware in there is completely "hard-coded" and doesn't require any software initialization to come on and start pushing pixels out the door. (Video cards that require programming something like a CRTC chip *don't* display anything if the CPU isn't starting unless the chip's registers are set to come on in a working base config; this is the case with the display chips in some old home computers, but not so much anything more modern.) That is also a really big strike against any idea that it's possible to "soft-disable" it.
  5. From a link in the last link: (Unfortunately the corruption that wipes out a few of the values appears to be in the original PDF for the Classic II Developer Note, at least the first version I stumbled across. But you can actually copy-paste the text out of that area if you have the PDF and see some of what's cut out.. )
  6. Gorgonops

    Color Classic doesn't boot off external HD

    Neither BasiliskII nor Mini vMac are particularly good for this because they both always treat virtual disks as if they were gigantic floppies. Therefore your can't run the tools necessary to create a valid disk/partition label which you'll need to have on the SD card. (It is barely possible to pull this off in BasiliskII if you can convince it to treat your SD card as a generic scsi device because this *will* expose it to BasiliskII in such a way that it "looks like" a SCSI drive for Drive Setup, but that's really picky to make work and it usually only works at all under Linux.) If you can't get SoftMac to run than you can probably do it in MAME, as outlined here: http://www.savagetaylor.com/2018/12/26/setting-up-your-vintage-classic-68k-macintosh-using-mame/ Just fair warning, MAME is really unpleasant and arcane to set up compared to any other Mac emulator. The last time I played with it the Mac emulation was also horrendously buggy. (As late as 2015 it couldn't even boot System 7. I guess that's fixed? Hard to tell because the documentation is so bad.)
  7. Gorgonops

    Is an inverter bi-directional: 74LS04 specifically?

    If the original LC *does* pass the FC3 code to the expansion connector because it expects cards to select on different ranges depending on whether it's in 24 or 32 bit mode and all subsequent LC machines don't then that's an annoying anomaly. It would *imply* at least that a card manufacturer that wanted to make a card that worked in all LC models would have to make hardware that groks and responds properly to both methods even if the low-address decoding is really only needed on the one model. That is one thing that has me a little confused, and makes me wish the original LC DevNote was out there in the wild. (Maybe the equivalent information is in one of the "Inside Macintosh" volumes.) The original 68020 Mac II shipped with that proprietary chip in the MMU socket that apparently provided some subset of the MMU's mapping capabilities to switch between 24 and 32 bit addressing mode. Given how the "D..." manual talks about "the computer hardware translates 24-bit addresses" and doesn't specifically call out the original Mac II as an exception I'd assume that if all it says about decoding is true then it must be capable enough to handle that... and based on that I naturally assumed the LC must include the equivalent functionality built into the chipset somewhere. But, I dunno, maybe it just doesn't? I guess you could technically get away with it since it has that hard 10MB RAM ceiling if you were careful about where you put everything else... with one exception? If the original LC actually supports the full 16MB normal slot space then you'd *have* to at least have some kind of switching to keep the ROM and RAM from being shadowed into said slot space when running in 32 bit mode. Maybe there's something in the chipset that suppresses chip select for all motherboard devices when the address bus is in $FE00:0000-$FEFF:FFFF? (My uneducated guess as to why the original LC/LCII don't have A28-A30 was to thwart trying to us the 256MB SuperSlot spaces to make a RAM expansion board or other peripherals that would violate the "cheap and cheerful" designation of the LC? Only good reason I can think of.) Given what you've got there is a network card that almost certainly only occupies the 1MB of minor slot's worth of memory and I/O then, yeah, it might make life easier because you "only" need to fake out the 32 bit $E enable on the PDS card to respond to your chosen alternate slot. In experimenting with the LC what did you read on the address bus when it was looking at the declaration ROM?
  8. Gorgonops

    Is an inverter bi-directional: 74LS04 specifically?

    Last broken record post, I swear. From the LC II devnote:
  9. Gorgonops

    Is an inverter bi-directional: 74LS04 specifically?

    Okay, if it's verified then I guess you know what you're doing. (I tried looking for specific discussion of that in the other thread, I really did, and honestly I just couldn't follow it through all the interstitial pictures of wiring looms. Maybe I need more coffee.) I'll just note one last time that my concerns are based on passages like this: (Page 133 of D..3rd ed:) This *is* in the NuBus section of the manual, but there are passages in the PDS section (that I think I've quoted before) that made me think that this translation still happens with PDS cards. But, hey, if I'm wrong I'm wrong. Do you have a reference that shows PDS cards actually need to decode both the standard *and* minor slot spaces? I assume the A28-A30 decoding issue is why you have the PLD in there. Are the "A22LC" and "A26" outputs from that chip essentially what's going to be used for device enable for the LC card?
  10. Gorgonops

    Is an inverter bi-directional: 74LS04 specifically?

    My point is that I'm not entirely convinced you are hitting the correct address lines. The Apple manual reads an awful lot like the MMU takes care of presenting a 24 bit view of the 32 bit normal slot space, that you don't need to have two separate sets of decode on the card. And if that is actually true then inverters on A20-22 are not going to change the address decoding in a useful way. To modify the 16MB slot space you should be playing with A24-26. And worse, if you really think there is going to be a problem with a conflict in 32bit mode you can't get away with ignoring it because it also reads to me like during hardware initialization it's going to be in 32 bit mode when it's looking for declaration ROMs, etc, regardless of what the control panel setting for the OS is. I also got the distinct feeling looking at the third edition of the "Designing..." Manual's LC PDS section that there are some wrinkles about how chip select works for LC PDS that are different enough from 030 PDS that you're going to need to address them too. (You did notice how the LC PDS is missing A28-30, right?) But, hey, maybe I have no idea.
  11. Gorgonops

    Is an inverter bi-directional: 74LS04 specifically?

    That is a really good point. You're far better off leaving the output waving in the wind when the jumper's not being used than the input. I still stand by my suggestion that this whole thing might be on the wrong set of address lines in the first place, but I might also be on crack for saying that.
  12. Gorgonops

    Is an inverter bi-directional: 74LS04 specifically?

    This is me being ignorant about the exact machinations going on in the parent thread again, and also probably ignorant about the requirements of PDS card re: 24 and 32 bit mode, but I'm going to toss this out there: I see you're putting inverters on the A20, A21, and A22 because you want to munge $A0 0000 into $90 0000. (Or was it vice versa? Whatever, it's not important.) Are you *sure* that's what you want to be doing? Here is why I ask, from page 307 of "DCaDftMF, 2nd ed.": IE, it was my vaguest of understandings that in a Macintosh a card didn't really need to worry its head about whether it was running in 24 vs. 32 bit mode, the hardware was always designed for the 16MB "normal" Slot spaces at F9xx:xxxx to $FExx:xxxx and the PMMU (or that simpler mapper unit that was in the Mac II and the original LC) was used to remap the first 1MB of that normal slot space into the 24 bit slice. *IF* that gibberish I said above is true wouldn't it follow that messing with the A20-A22 address lines would at best be unnecessary and at worst be deeply counterproductive? I dunno, maybe I'm totally missing something here.
  13. Gorgonops

    Is an inverter bi-directional: 74LS04 specifically?

    Shortest answer: no. Followup: why in the world do you think it would need to be here? I haven't been following the other thread particularly closely but my vague understanding of what this inverter is for is to change the address at which some hardware on the peripheral card you have there will "wake up". Unless this peripheral is going to be doing bus mastering it's always going to be the computer driving the address bus lines so... again, why would you need the inverter to be bidirectional?
  14. Gorgonops

    Teac

    There is no pin on a shugart connector that lets you vary drive speed (pwm-ing the motor signal would just kill the drive) so if it does vary speed then that drive mechanism *is* special and nonstandard. What model drive is it? Some drives of that era have marks on a visible turning part that you could check with a timing light. If it has an exposed spinner you can put a pen mark on I'd guess you could eyeball the difference between 300-something and almost 600 rpm.
  15. Gorgonops

    Teac

    I think some of those companies making third party drives would start with a compete standard "Shugart interface" drive and retain (instead of disposing of, like Apple did) the original interface board and literally chop and hotwire it as needed. (IE, for variable speed they'd cut the line to the PWM speed controller on the original board and pull it to their add-on daughterboard while retaining the original board for stepper motor functions, etc.) I'd be interested to see a picture of its guts.
  16. Gorgonops

    Teac

    Yeah. The common thread with all of them is since there's no way to vary the drive speed with a standard mechanism you've got to be able to vary the data rate on the controller instead. (Geeky factoid I love bringing up: this is how Commodore did the same trick as Apple in storing more sectors on the outer tracks of the disk than the inner ones. Even the lowly 1541 does it, using a programmable counter to change the clocking of the output shift register. This is mechanically a *far* better system than having to speed up and slow down the disk platter like Apple came up with for the Twiggy and reused on the 400/800k Sony drives.)
  17. Gorgonops

    Teac

    Technically it's possible to read 800k Mac floppies in a normal floppy drive with a sufficiently krazy controller, like the USB Kryoflux device. (Older examples include the "Catweasel" series of ISA/PCI/Amiga disk controllers, and Central Point Software's "Copy II PC Deluxe Option Board".) But, yes, no off-the-shelf USB floppy drive can do it. I also don't believe the KryoFlux is capable of writing disks, just reading them. At least with publicly available software. (I don't know anything first-hand but I've heard some strange things about how the outfit that makes them keeps certain things close to their chests.) A Catweasel can, but last I checked those things were solid gold plated on the used market and definitely won't work under OS X Mojave.
  18. It is excellent how that manual has a lot of the declaration ROM code in it, along with some descriptions about how the ROM, VRAM, and I/O spaces are broken up over the Nubus slot space. (Yes, it's a PDS card, but it's following the slot manager conventions.) In theory I suppose it's mostly what's in the Toby documentation in the Apple manual, but it still might help fill in some of the gray areas.
  19. From what I remember from scanning the "Designing..." document I didn't really think there was any explicit barrier to piling as many functions as you want onto one card (within reason) so I'm not really surprised that a video+Ethernet card was a thing that already existed. Since I didn't know for sure, however I threw the "RTFM" warning in as a precaution. As an aside, I've noticed that the phrase "standard QuickDraw acceleration" is something that appears nowhere outside of LEM video card profiles. A jaded part of me is starting to question how many of the cards so described are actually "accelerated" in the same sense the 8*24GC is.
  20. In theory at least if you cooked up NuBus transceiver logic that could be interfaced to a "Pi-esque" SBC that could push packets at some reasonable fraction of the practical, real-world speed of the bus (which until someone can show me evidence to the contrary I'm going to peg at maxing out at around 10-15MB/s despite the *theoretical* capacity of a Nubus burst transfer being around 40MB/s) then so far as I know there's no reason you couldn't have one Nubus card pretend to be, I don't know, say a video card, a network card, and a storage device all in one slot. The only limitation I can think of is if there's some restriction on how much I/O space you can have on a card that's also a framebuffer, or if the Slot Manager software framework has some limitation relating to drivers for multifunctional devices or... whatever. As to "offloading processes" how possible that might be depends on whether you're talking about writing your own software or making something that magically accelerates existing software. In principle I could see, I dunno, writing replacements for things like the SANE numerical libraries that can offload some FPU functions to the much more powerful FPU you have hanging off the card, but how practical that is and how much gain you could possibly get out of it would probably depend a lot on how much massaging it would take for the native Mac data formats to take advantage of the alien hardware. You could certainly present new device functionality like, say, SSL/web accelerator APIs or a web media format processor you can throw JPEGS and MPEGS at to convert into bitstreams you can handle more easily on a feeble CPU, but obviously this requires all new software. In any case, this is totally outside the "make a video card" scope defined in this thread.
  21. So far as I'm aware your memory is basically correct. Technically the high-end original Quadras (900/950) have the same I/O coprocessors (condensed into a higher integration part?) as the IIfx but, likewise, I don't think they actually do anything with it.
  22. I just went through my eBay history to see if I could link directly to the listing I got it from; it's expired (I had these things sitting on myself since last year, it's taking me this long to get to them ), but I don't think there's much variation between them for the most part. (The FlashFloppy website does refer to an "Advanced Gotek" that has extra jumper pin locations and solder points on the board for, among other things, driving SD cards directly instead/in addition to the USB port, but I haven't seen any listings for one explicitly.) The ones I bought were almost the cheapest ones I could find, I paid only $28 for two of them from a listing like this: https://www.ebay.com/itm/3-5-1-44MB-USB-SSD-Floppy-Drive-Emulator-for-YAMAHA-KORG-Elec-keyboard-GOTEK/162527019254 (The particular seller I got mine from isn't listing them anymore, I think it's just one of those many "drop ship from China" presences that essentially sell random items.) At the same time I also bought four of these little guys, two for the floppy emulators and two to play with: https://www.ebay.com/itm/Blue-IIC-I2C-0-91-128x32-OLED-LCD-Display-DIY-Module-3-3V-5V-For-PIC-Arduino-/332048200050 Getting the headers soldered to them so I can install them is something I'm hoping to squeeze into the weekend, but they're not really necessary. To flash them I went with the "A-A" USB cable method because of sheer laziness. (I just bridged the necessary enable pins by inserting some fat speaker wire bridges into the holes where the header pins would go; most Goteks don't have them factory installed.) The cable cost me something like $5. Unfortunately FlashFloppy only does Shugart (or at least Shugart-like, which covers quite a lot of systems outside, alas, the big three of Apple, 8-bit Commodore, and 8-bit Atari) emulation at the moment. I have wondered if it might be possible to use the Gotek floppy hardware to do Disk II emulation with suitable firmware and cabling changes; the CPU on the Gotek should be fast enough to handle it. But it's definitely a feature that doesn't exist yet.
  23. I have no doubt there are a few pallets of the needful manufacturing equipment sitting in a dark warehouse somewhere that might someday rise like a phoenix from the ashes, but somehow I think the original disks are going to have to get rarer before you find the seed money for that.
  24. Hopefully. But I am starting to feel like that as much as I'm loathe to I should figure on starting to move as much as possible to floppy emulators. (Just this week I flashed my first pair of Goteks with FlashFloppy. Initially got them intending to put one in a TRS-80 Model 4, but I think my recent Tandy 1000 EX acquisition has jumped to the front of the queue. Need to get some ribbon cable and adapters still, though. Feh.)
  25. Gorgonops

    Does the LC III support RS-170 NTSC?

    I guess I failed to get NTSC video out of it, but on the bright side my LC III seems to be in decent health: (Monitor adapter showed up today.) I imagine to be safe I should prepare to proactively recap it, but for right now it's chiming and the board looks pretty clean so, yay! I'm particularly pleased that the SIMM I found rattling around loose in a cardboard box without an anti-static bag seems to work fine. Next job is to try it out on the network, I guess.
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