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mattislind

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  1. mattislind

    Strange Mac SE startup anomaly

    I agree that 5.2V should not be able to trigger the the crowbar but the clicking sound is very typical for an emergency shutdown in the PSU imho. The source might for example be over current or over voltage. In the Sony PSU both the 12V and 5V outputs together control the emergency shutdown. A quick glance at the schematic give that above 6.2V at the 5V or 15V on the 12 V would trigger the emergency shutdown. A reason for false triggering could be excessive ripple due to bad filtering capacitors. Check ripple on the 12V and 5V before the filter inductors. Put dummy loads on the 5 and 12 V outputs and temporarily disconnect the zeners for the overvoltage system. Meassure ripple both before and after the filtering inductor. Since the overvoltage system is measuring both voltages simultaneously uneven loading of the PSU can give this type of problems. I have seen this previously in s MicroVAX 2000 which need to have a dummy load if the hard disk is removed. As far as I see it a capacitor stay reformed for quite some time. I find it unlikely that a capacitor heating up is creating this kind of repetitive cycle.
  2. mattislind

    Strange Mac SE startup anomaly

    Can it be the crowbar in the PSU which false triggers? This repair guide page 10 mentions the crowbar.
  3. mattislind

    Dayna Mini Etherprint

    It is 5V 1A /Mattis
  4. mattislind

    Asante Maccon SE/30 drivers?

    Many thanks for the driver! Now my SE/30 is on the net running System 7.0.1 and Mosaic 1.0.3. /Mattis
  5. mattislind

    Asante Maccon SE/30 drivers?

    I traded a Radius board for a Asante Maccon board for my SE/30 and now I need the drivers. I failed to find them through google. Anyone has them? Downloadable? /Mattis EDIT: Maybe I should have written diagnostics disk. So I could check that the card is found in the machine.
  6. mattislind

    MacIPgw VM 3.0 | TCP/IP over LocalTalk gateway

    There is apparently a widespread misconception that LocalTalk is what we commonly know as asynchronous serial communication. Well. It is not. LocalTalk is 230400 bps FM0 coded bit synchronous SDLC. It is all described in this book Inside AppleTalk. Check Appendix A for more details. So just put a serial cable and a USB adapter would not get you anywhere unless you also go for the AppleTalk Remote Access suite. There is also AppleTalk over PPP according to RFC1378. The remote end also need suitable software to handle ARA or PPP. I think it would be easier and better performancewise to run LocalTalk to a bridge and then Ethernet to the MacIPGW.
  7. Good work Mactjaap! And a very nice matchbox as well! I still have the modern-HW-LocalTalk project sitting back in my mind but it won't happen in the near future unfortunately.
  8. Yes. There seems to be a widespread misconception here that "serial is serial". Of course it is not just serial. There are different connectors, different voltage levels, different link protocols and different line encodings. As stated LocalTalk is SDLC/HDLC. But it is using FM0 line-encoding which is self-clocking so external clocks are not necessary. The clock signal is conveyed embedded in the data signal. To extract the clock requires a clock recovery circuit (or software). I been thinking a bit what can be done. But my time for projects are limited. 1. Bitbanging directly from the OrangePi - requires really good knowledge of how to deal with the kernel to meet real time requirements. 2. SPI-port with external clock recovery hardware circuit. Unfortunately no Linux is supporting Slave mode SPI. 3. SPI-port oversampling the LocalTalk signal with 8 times the speed. 1843200 Hz. Then do clock recovery in software. Can it meet the real-time requirements? 4. Using a simple Atmel AVR uP to do the heavy lifting of the clock-recovery and HDLC framing. Then use Master SPI on the Pi to transfer the data to the Pi. 5. Use the PRU on a Beaglebone Black to do the clock-recovery and HDLC framing. In any case some external RS-422 adapters are needed. It would probably be a fun and educational project but as said, my time is limited right now.
  9. I did a quick write-up of my experience with MacIPPi and how to get it working. It is here.
  10. Maybe not a commodity, sure. On the other hand the amount of people doings this kind of networking experiments are quite limited. I see these devices all time at Ebay. They are not directly selling quickly. Search for Dayna Etherprint for example. Not extremely high prices. I bought mine from this this organization in Switzerland: http://www.revamp-it.ch/index.php/en/shop-en/externe-netzwerkgeraete-en/dayna-mini-etherprint-plus-detail
  11. Have you looked into what you could do with the PRU on the Beaglebone Black / Texas Sitara? A really interesting thing. I haven't played with it myself but a guy made a MFM disk emulator based on the PRU coprocessor. It reads the and writes the 5 mbit/s data stream in realtime. I have tested the disk emulator and it works very nice. Essentailly the PRU is executing at 200 MHz hard realtime. No kernel or caches that would make it non-deterministic. It could sample the signal and do full HDLC decoding / encoding as well as CSMA/CA handling, implementing the full link layer. Unfortunately I have no time for doing such a project but it should sure be very interesting.
  12. BTW here is the a pdf of the book "Inside AppleTalk" that probably cover all of what you need to know on AppleTalk and LocalTalk. Way back as a student I bought this book for hard earned money. I had an idea of a project (much like the macippi but using a PC) but it never materialized. I do remember that the Z8530 is a quite annoying chip to program. I still have the book somewhere though. /Mattis
  13. I am not 100% sure what mactjaap want to do but I would assume it is to get rid of at least the LocalTalk to EtherTalk bridge and maybe the LocalTalk adapter, but still connect to the OrangePi over AppleTalk. Not using PPP over async serial IO. I understand that since one of the beauties of the old Mac is how simple you network them. Plug in the LocalTalk cable and it just works. File sharing, Printers etc. Way before Windows for workgroups. The point is that RS-232C is really only an electrical interface which specify voltage levels and connector usage. It doesn't say anything about the actual level 2 protocol used. In the case of LocalTalk it is not async serial communication. It is HDLC with some twists. The communication takes place on a bus network and uses a CSMA/CA method to access the bus. It means it continuously monitor the same signal that it is sending. The MAU is the LocalTalk adapter. I once saw someone that attached a 8530 chip to a BeagleBone: https://mac68k.info/forums/thread.jspa?threadID=275 On the other hand with the horse power of the PRU realtime coprocessor of the Beaglebone it should have been possible to do it in there instead. Or just maybe it would be possible to bit bang in the OrangePi, but it would certainly require some kernel skills to be able to handle it reliably. Doing async serial IO and then put pppd on the eorangepi should on the other hand be comparatively easy if one want to take that route instead. /Mattis
  14. Well. It took me a while to get a grip of how Apple stores files and how to get them on to the machine. I am used to Linux and MacOS X and have never heard of AppleDouble. So it took some time to come up with a solution to first use stuffit expand to repack files into Macbin and then have them unbin:ed on the orangepi netatalk AppleShare directory. Then I simply didn't understand that MacTCP was a setting and not an application. It took some time until I dragged in to the System folder and then it worked. But setting up IP address with MacTCP requires some patience. But in the end it worked. Say hello to google DNS! (An Apple Iphone 7 taking a photo of its great grand father. I would have thought might have delivered a better result...) Then onto the topic findin a browser that worked on a Mac Plus with 6.0.7. The number of choices seems to be just one. MacWWW 1.0.3. Not the best browser around. It is not handling much at all actually. It is not very happy with redirects so www.google.com isn't any good. Most pages are simply too complex. And it crashes as soon as one closes a window. The apache test page on one of my servers works though. So in all the mactjaap orangepi works perfectly, almost. But it is not his fault. There seems to be a bug in the Ethernet driver of the kernel which causes it to lose Ethernet connection and spam the log file now and then. Restart is the only way out of it. Then of course it isn't very useful since the number of web browsers that are available on 6.0.7 is so limited. Maybe I try to upgrade to system 7 or try to find lynx for system 6.0.7 Thanks a lot mactjaap! /Mattis
  15. Hello mactjaap and everyone else! I can now confirm that the new image is much better. It boots fine. It includes the magcipgw and netatalk daemons. This far I have only tested that I can reach the orangepione AFS server over my localtalk which is connected to a Dayna Etherprint Mini. It mounts the share on the orangepi perfectly. Haven't got around to test the macipgw part yet. I need to put MacTCP on the orangepi so that I can copy it to my Mac Plus. Will report the back the progress later on. One caveat though. The image is 7.97 Gigabyte uncompressed. The SD card that comes with the OrangePi kit is only 7.95 Gigabyte. Not 100% sure that this will cause any trouble. Maybe a simple fsck will fix possible problems. I didn't take a chance so I used a Samsung which was 8.03 Gigabyte instead. So in all, really good work mactjaap! /Mattis
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