Jump to content

Phipli

6502
  • Content Count

    18
  • Joined

  • Last visited

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. Phipli

    Nubus Ethernet Card Software

    Interesting, thank you Bolle. We could do with a few more like this one for the collection. Ethernet makes it a lot easier to move things between old and new machines.
  2. Dumb question... if the II and IIx are in part slow because they were designed for 120ns RAM and have a large number of wait cycles... if you have faster RAM is it possible to change the number of wait cycles in the ROM, for example with a ROMinator?
  3. Phipli

    Nubus Ethernet Card Software

    All sorted, don't mind me. It was just jumper settings. I can now FTP files straight from my ARM SBC NAS to my 1988 Mac in 7.1 and don't have to faff with passing files down a chain of formats and computers Excellent!
  4. Phipli

    Nubus Ethernet Card Software

    Awesome - the following site showed me the right jumpersettings for RJ45 connections! https://stason.org/TULARC/pc/network-cards/C/CNET-TECHNOLOGY-INC-Ethernet-CN460E-REV-A.html
  5. Hey folks, Does anybody have the software for this card? Or know where I might get it? Possibly something like a CNET 460e?
  6. Phipli

    Broken Macintosh II Repair

    Reading values in circuit isn't reliable. So... Weird non stable : there might be a cap in parallel and your meter is charging it. Way off value : If you're reading a 1k resistor, and there is a second 1k resistor in parallel in the circuit, you'll read 500 ohm. Components that aren't resistors can cause this. You shouldn't expect to see marked values in circuit, but it is a way of comparing with another machine. Slightly off readings : in addition to the same as above... not all parts are created equal. Sometimes you don't need an accurate value componet - for example, a resistor in an ADC might need to be 0.1% accurate... but a pull-up resistor might only need to be within 20%! To save cost you use low accuracy components where you don't need precision. My advice - concentrate on checking continuity. Also, take care that you're not fixing a broken connection by pushing down on it while measuring! I'd put fresh solder on pins that look excessively crusty, although I'd only remove a chip as a last resort as putting too much heat into something might kill it. Check every identified pin is connected to each destination on this schematic : https://www.downtowndougbrown.com/2015/03/explanation-of-the-macintosh-iiiix-power-onoff-circuit/ If you find a difference, check with another owner of a II, just in case you have a different board revision - you don't want to fix things that aren't broken! I'll help if I can as I've just gone through the same thing... but I have a IIx which as a different layout and some component labels are different... even before you get to the real differences! Note you say about fixing a trace to C6 - on my IIx... C6 isn't the same capacitor! If I'd done that repair I think it would be wrong! Have a check with continuity + following traces and make sure C6 is the part that the schematic says it is and that you haven't made an unintended change. Good luck!
  7. Very interested in this. These look easy to copy if you could get the timing right : https://www.worthpoint.com/worthopedia/4x-4mb-apple-mac-ii-iix-30pin-tin-non-1825526434 Thats a quad or isn't it?
  8. Phipli

    mac iici unfixable?

    I don't think it will like having 1 RAM simm missing, remove the whole bank of 4 Anything is fixable, but it might take time and a steady hand. How much SMD soldering have you done? The IIx I've been working on only needed 7 trace fixes so far and it is mostly working now. But yours looks worse, unless someone had cleaned mine. Try to save it - IIcis are probably one of my favorite macs. I was saying to my dad it is a shame they never made a IIi (as in a not compact IIci) - a 25mhz bigmac with integrated video and a floppy port
  9. Phipli

    Resurrecting a Macintosh IIx

    Woo, worked out the graphics issue - the monitor didn't like been overclocked that hard from the IIx. It is usually ok at 75hz, but for some reason it wasn't here. At the moment I've found that it runs at 72hz in 800x600... still technically too fast, but the screen copes. Just disk and possibly pram issues now! So close! From dead to photoshop in ~3 weeks!
  10. Phipli

    Resurrecting a Macintosh IIx

    davidg5678 Thanks for your response and good luck with the II. I started by repairing all trace damage I could see and checking the continuity of what looked suspect, then beeped out each connection on the power circuit that I'm sure you have seen, scribbling out each link one at a time. Sadly the component labels don't exactly match my machine - e.g. D4 and D6 are reversed, and I C6 isn't C6 on my board... never found what it was! I also renewed the solder on some of the suspect chips - the SCSI chip, the UB1, UB2, UA15 and UB15. I need to replace the 7905 as that is crusty and might be causing issues with the power to the HD. I have some I think... More luck last night. I got it booting from the external SCSI. I currently suspect the SCSI cable or traces to the internal port... or the HD being weird. Yes, the flux is mostly cleaned - but it is also "no clean" flux so I haven't done it 100% yet until I know I'm done. Trying not to waste IPA as it is expensive atm. Planning to re-soldermask where I removed corrosion too. I need to double check the PRAM circuit as I think it isn't remembering video settings. Also get an older version of the video drivers now that I have it booting from something bigger than a floppy. Still not worked out the graphics - no other card to try, or Nubus computer to try this one in. The VGA adapter works fine on everything from a 6100 to a 9600. Don't have any other 68k macs here with video out to try.
  11. Phipli

    Resurrecting a Macintosh IIx

    So more investigating - I swapped in a working floppy drive and the machine will boot from a floppy! This means it only seems to crash when trying to boot from scsi... Plus the washed out video. Photo of it booted in System 6 with a drive from a 6100
  12. Phipli

    Resurrecting a Macintosh IIx

    Interestingly, it doesn't reset itself when there is no startup disk at all (and the question mark is flashing). Does this mean it fails when RAM gets busy as the OS starts to load in? (I assume that the flashing question / disk runs entirely from ROM). Because of this, I feel the issue is less likely to be the power circuit, unless it is having a brownout when something happens that drags the voltage down? Perhapa a trace has continuity... but is too thin to carry what is required of it? At least it has always done this so it isn't my repair I tried some different RAM in it just in case - I knew it was probably incompatible because it was high density + low chip count, but if nothing else I wanted to check that the symptoms are different with the wrong RAM. Yup - it just straight up chimes of death with 4 16MB simms in bank A... I didn't really expect any different. I saw something about a diagnostic mode that you can access through the modem (I think) port - has anyone used that before? Please forgive my soldering! I checked for shorts, and it is enamelled wire.
  13. Phipli

    Corroded Chip

    Awesome to see such old machines still in a production environment. Regarding the contamination on the CPU - looks like residue from a heatsink someone added. Was probably because of that hot environment you mentioned. Thanks for keeping them alive
  14. Good afternoon folks. I recently picked up a dead IIx. It wouldn't even bumpstart when I first saw it, but I'm not sure why as it sort of did once I got it home (it chimed and showed the happy mac before doing a weird restart with no chime - after a couple of times it froze). Note that it does not restart if there is no disks connected. Additionally, the video is pale and washed out, except once in a while when it is normal. It is now a couple of weeks later and I've spent the weekend researching and repairing. I've fixed 6 broken traces and checked lots more in the power circuit. I've re-capped most of the motherboard (I don't have a replacement for the yellow 10uF or the axial 220uF (might have the value wrong - it almost faces the board!). The power on circuit now works from ADB and the button on the back. Machine is a late variant (March 1990) and has a soldered CPU and factory battery holders (no funny little board or capacitor). 8mb of RAM, Radius 24 Pro XK, ethernet and a 540mb disk. At some point someone had a Radius Rocket in it, but sadly that is gone. Does anyone have any suggestions for what might be wrong? I don't know the machine's history so it could even have the wrong RAM fitted for all I know. Issue summary: 1. Restarts silently without an error while showing the Happy Mac. 2. Video is washed out. Youtube video for reference : https://youtu.be/Dca4S1n8_VI
×