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GeekDot

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About GeekDot

  • Birthday 08/21/1970

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  • Website URL
    http://www.geekdot.com

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  • Gender
    Male
  • Location
    Yurop - Go see the Queen
  • Interests
    If it beeps and/or blinks, I'm in!

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  1. GeekDot

    Carrera040 Info / Hacking Thread

    Awesome, "Dicker"!
  2. GeekDot

    Carrera040 Info / Hacking Thread

    LOL - love you too, bro! ...and QuickDraw just uses, whatever method the driver offers to set pixels. So what the heck, I've disassembled the SE/30 driver-ROM, too. See the disassembly here https://github.com/axelmuhr/Carrera040/blob/master/se30vrom.asm - the most of it is sRecords and the dev-team rightfully celebrating themselfes Having a look at line #531 you can see how it's done: A simple move.l to the screenbase at 0xFEE08040. So 32bits are written "at once" and there's no simple software explanation why there's a 'whiteout' in the 3 byte resulting in those stripes you can see 3 posts above this. It has to be hardware timing... I tried delaying the clock using a 74LS31... Delay Pins Result 6ns Inverted (NANDed) (5 NAND 6) -> 7 Stripes plus Buserror 12ns (5 NAND 6) -> 7 ->(10 NAND 11) -> 9 Hangs (like 1:1 clock) 23-32ns Inverted 1 -> 2 Stripes (roughly equals NOT) 45-48ns 3 -> 4 Stripes 51-54ns Inverted 3 -> 4 -> (5 NAND 6) -> 7 Hangs (like 1:1 clock) So effectively only delays of ~23-48ns result in a kind of successful boot - both are close to a 50% clock-shift (plus propagation-delay) of the 63.82ns duty-cycle of the 15,6672MHz from C16M. This is, where I'm a bit lost ATM... are we looking at a phase-shift issue here? Or do we need to stretch timing vs. just delaying it? I wish I were an educated engineer...
  3. GeekDot

    Two SE 1/20 do not accept floppies

    Do you mean the filters M/C 8908L 115-0002 (yellow DIPs).... these seem to be compatible with https://www.bourns.com/pdfs/601.pdf, still hard to find, and no idea how the check the internal R-C-R network of each pin-pair... The floppy cables are "red-stripes".
  4. Hey Gang, so here's a IMHO tough nut to crack... Just got two SE 1/20. Cleaned them etc. and both boot fine off their screaming original 20MB HDDs. What puzzles me is that both(!) refrain to accept every floppy-disk being fed to them... either instantly ejecting or offering to format them. Yes, the disks work fine on other Macs. Trying to format a fresh 1.4M or 800k disk results in happy grinding but ends with an Error. So out went the original MP-F75W-01G, complete clean'n'grease, positively checked with another Mac and back into the SE. No change. Ok, got a MP-F75W-12G from 'the stack(tm)'... no different. So these are the ROMs: ...and the PCB printing: Any ideas? As I can't add any software to them, I'm not able to check the ROM id if it's actually an FDHD one (ROM ID: $037A)...
  5. Sorry for my ignorance... I'm (still) so deep in that damn challenging SE/30 vs. Carrera040 thing that I hardly look left and right Yes, the power-button works like it does with the original PSU - but I can't guarantee that for the 'locked state' as I don't have a key for the lock And no, I haven't had the time (yet) to start to design something nice... so feel free to go ahead PS: I have a spare Q950 board - after doing a closer inspection I saw that the "L6" inductor next to the CPU oscillator (66.6MHz) went "poof". Anyone here with an LCR-meter able to tell me it's Henry value? The other inductors used with oscillators all over on the board are 3.5uH (+/- 0.2)...
  6. GeekDot

    Quadra 950 PSU died... <cry>

    1st of all when you do a PS replacement, the new one is probably much smaller than the original, so there aren't so many obstacles in the PS case anymore. Plus a more recent PS emits less heat. 2nd, the fan sucks the air from the case and blows it through the PS to the outside (instead of sucking the case's heat through the PS) These 2 points will IMHO lower the pressure requirements a lot. While I can't find the original anymore, it's a standard 120mm 12v fan, so no worries about that. BUT the original was much "thicker" than those standard PC ones. So you might need shorter screws to mount it. Caution: Don't use the original screws if you're just replacing the fan and not the PS, too. The screws will then touch the PS PCB and might short it or lead voltage! "Gefahrenzone!"
  7. GeekDot

    Quadra 950 PSU died... <cry>

    I'd say that's the root of all issues.... given there's not just a mildly warm 68030 (not mentioning accelerators), a hard-drive, power-supply and most important -and usually very uncommon- a CRT in this small case, static pressure is the main point when it comes down to cooling. On top of this, it's just 60mm in diameter so 2mm H₂O pressure is where I'd start counting when looking at the, well, sub-optimal airflow channels in the cramped case.
  8. GeekDot

    Quadra 950 PSU died... <cry>

    I don't see any necrotic thing going on. This thread is here to stay Anyhoo, that Noctuas NF-F12 is one hell of a fan and definitely a good fit for the job... I was just too cheap to spend 20€ on a fan (and had that spare BeQuiet in my drawer), "also hau rein das Ding!" As for the original fan, give me some hours digging for it...
  9. GeekDot

    Carrera040 Info / Hacking Thread

    Discussed this clocking "suspicion" with Bolle already (We're quite busy behind the scenes ;-)). I traced the CPUclk (SE/30: 15.6672MHz) coming from the PDS slot to both FPGAs 'TclkIn' pins. Also, the 040s 33.3Mhz clock is fed in there. So my initial (stupid) WAG was, that these two clock-domains used in the FPGA VHDL/Verilog might get into some troubles (Given the FPGAs have to do the dynamic bus-sizing translation between 030 and 040). This would lead to different clocking-ratios: Mac IIci ~x1,25 Mac IIsi x1.6 SE/30 ~x2.10 Who knows how clever their state-machines were designed.... but then it stroke me: Dang! The II[c]x has the very same clocking and these were supported by direct-to-socket adapters. And if my eyes aren't betraying me, the clk-pin on @nickpunts adapter is going straight to A38 on the PDS slot. That said, Nick, it would be interesting to know where A3 (/BUSCLK) is connected to on your adapter... Next up was the load being put on the clock-signal. I have the short version of @Bolles adapter, sitting on the NIC which also lives off the clock-signal, but "Designing Cards and Drivers..." has the answer: SE/30 - Drive: 40 uA /0.4 mA, 30 pF IIci - Drive: 10 uA/0,1mA, 15 pF This means litte SE/30 has more ooomp to the CLK signal than his bigger cousin. So my current "hot trace of the week(tm)" is timing - i.e comparing different runs with my logic analyzer etc. - also I think I won't get around building a 1:1 PDS-interposer to eavesdrop my IIci while smoozing with the Carrera.
  10. GeekDot

    Carrera040 Info / Hacking Thread

    Another quick update: It's getting clearer every day that little SE/30 and Lady Carrera have an hardware "issue" within their relationship (current status: It's complicated)... Because the INIT code gets quite far (beyond the 68040 init routine) every 10th-15th try it simply can't be just the driver. There must be some communication/timing issue... That said, my logic analyzer just got additional 16 channels (totalling 32) giving me a broader look into what's happening. Because it's always good to know how others solve(d) the same problem/task, I also started to disassemble the Daystar Turbo 040 ROM.... and at about 4000 lines of code I got caught red-handed BTW: The Turbo 040 (Rev 1 to 3) looks very much like a by-the-book implementation of what is written in section 7 of the "MC68040 DESIGNER'S HANDBOOK", which is good for a better overall understanding.
  11. GeekDot

    Multiprocessor SE/30!

    A bit late as I just stumbled across this threat, but I know of one 68k-Monster (68020 that is): The mighty 'Suprenum'. Running 256 nodes, each featuring a 20MHz 68020/68851/68882 plus a vector floating-point unit from Weitek. Its OS was called 'PEACE'... there definitely was some love for contrived acronyms https://en.wikipedia.org/wiki/SUPRENUM
  12. GeekDot

    Carrera040 Info / Hacking Thread

    Hey Gang, Thanks @nickpunt, @trag and @Trash80toHP_Mini for your motivating comments. This helps to keep on writing... crazy what I knew back then and already was about to forget (suffering from "project-ADHD" ). So good to have a "code refresh" while documenting all this in more detail. That said, prepare for some serious brain-tease (if your brain hasn't already imploded ) in the just posted part 2: hhttp://www.geekdot.com/carrera-in-se-30-code-part-2/ Because I don't want to clutter this thread by upcoming "Hey, new post published!" comments, just follow me on Twitter to get pings about new posts: https://twitter.com/geek_dot
  13. GeekDot

    Carrera040 Info / Hacking Thread

    Wow... nearly 10 months since the last post! This and the fact that 68kmla had a moment of rest in last weeks I thought it would be a good thing to document my work on the Carrera 040 driver in a place I can control and also have all the means to create a layout fitting the requirements of describing 6000+ lines of 68k assembly Yup, I will guide you along what I've done the last year+ (with pauses) and am still chewing on. So click the link for your amusement, enlightenment or participation: http://www.geekdot.com/carrera-040-in-an-se-30/ Because of its sheer size, I'll add more chapters/post over the time until we're all on the same page. Sometimes it just needs more eyes & brains onto a problem to see the obvious.
  14. GeekDot

    Quadra 950 PSU died... <cry>

    Thanks, glad if this is useful for somebody else! As for the todo-list: I need to "clean" the remainders first as I promised the parts to someone else who is on the mission to repair an old PS "the correct way" as @techknight would probably say Hopefully this is been done this week - suffering severe vintage-project-ADHD I got dragged into other realms of resurrection (http://www.geekdot.com/the-mips-rs2030/) and need to force myself to return to the good ol' Macs (not to mention the SE/30 vs. Carrera040 riddle still waiting to be solved).. 1) Well, there's certainly a higher efficiency with good, modern power supplies. This means it will waste less watts coming "from the wall" to feed you Quadra, i.e. saving $$$ That said, mine is a crappy, cheapo and example of bad engineering, so I doubt it's that much of a saver. OTOH lady Quadra is not running 24/7 so the impact is negligible. 2) Yes, you have to have the case open no matter if you're planning to replace the fan or keep the original one. This is because you have to somehow adapt & connect the new or old fan to the replacement PS. The noise level is of course related to the fan quality you choose. I picked an average one (~10€) which is much more silent than the original one. You can probably go some db lower by spending the double amount. Again, there's a nota-bene: The PSU fan ist the only fan for the whole system - a principle many vintage machines followed (read SUN/SGI and the like). Thus the fan had to pull the heat through the PSU while having enough juice to cool the PSU, too. So todays measure of "CFM" ( cubic feet per minute) isn't sufficient to choose the right fan for an original PSU: You have to make sure the static pressure (which tells us how good the fan is at sucking air over various objects at its intake) is within the specs of the computer manufacturer. Here's an example from the SGI-World: The EBM Papst 8412N running at 3100rpm has a CFM of ~40 and a static pressure of 4 while the often used & modern Arctic F8, delivering a nice CFM of 30 @ silent 2000rpm, has a static pressure of just 1. Not enough to cool the computer itself. It'll cook itself to death sooner or later. It's a bit like horsepower vs. torque with cars. Figureing out all these specs is quite hard today. Again, because you bravely swapped your Quadras PSU to a newer, modern one you don't have to care about this as these PSUs aren't getting that hot and an average PC fan is just fine - not sure how much this is true for a fully loaded Q950 with PPC accelerator and 4 hard-drives, though. P.S: A nice side-effect: My Q950 is much lighter now! You can really feel the difference when hauling the beast around...
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