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About GeekDot

  • Birthday 08/21/1970

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    Germany - Hamburg
  • Interests
    If it beeps and/or blinks, I'm in!

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  1. GeekDot

    ROM Dumps: SE/30 Video ROM and TOBY DeclROM?

    ...and I've disassembled (and partly commented) it over here: https://github.com/axelmuhr/Carrera040/blob/master/se30vrom.asm
  2. Hey gang, After many moons of waiting on my todo-stack, I finally repaired my Radius Rocket. Runs fine and all... ..but there's one strange thing I came about when doing nastier things than running MacBench: It claims not having an MMU (while the installed 68040/25 certainly has one) - the 'mmu ' Gestalt return-code is empty. I'm not the first one stumbling across this, like this guy in 1999... and it looks like there are some more 040 accelerators not providing MMU functionality. A quick measurement showed they're asserting /MDIS ("MMU disable", pin S6, pulled high)... anybody every heard why they did that? I was under the impression that a Rocket is a completely "sandboxed" Q9x0 minus I/O and own bus.
  3. GeekDot

    Fan replacement for a Mac SE/30

    Hi - Just to throw in my 2 Euro cents here: All I've read in this thread is RPM, decibel and CFM... but you're totally missing one important number: Static pressure (Measured in 'mm/H2O' or sometimes in 'Pa') Especially systems been cooled by sucking air through the whole box having obstacles (i.e. power-supply, big objects like humongous caps etc.) in the way of the draft it's all about how much 'ooomp' poor little fan can deliver. It's a bit like horsepower vs. torque. Nocturas and the likes are the Ferraris in the world of fans - lots of HP (CFM) but comparably low on newton meters (mm/H2O). And then there are the tractors. Not the fastest and nicest ones... but boy do they pull. My '30 has a Panaflo FBK06-12L - can't find a datasheet for it, but its 40mm brother has a static pressure of 2.5 mm/H20 - I dare betting the 60mm Panaflo is at least pulling 3 mm/H2O. The recommended Noctura is at 2.18 mm/H2O The recommended Delta Electronics AFB0612EH-ABF00 is at a absurdly poor 0.544 (@38.4 CFM) So if there's not enough draft, after some hours your PSU might get cooled ok'ish, the flyback's already sweating and the the harddrive is about to be grilled by that Turbo040 down there... So in a one sentence: "Don't look at CFM. It's mm/H2O that matters!" (At least in the case of compact Macs... pun intended ) I've written a bit more detail in this post over here.
  4. GeekDot

    Carrera040 Info / Hacking Thread

    Awesome, "Dicker"!
  5. 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...
  6. 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".
  7. 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)...
  8. 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)...
  9. 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!"
  10. 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.
  11. 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...
  12. 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.
  13. 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.