#Mac se floppy emulator zip file#

This resulted in dead pixels on what would otherwise be a perfect raster screen typically showed when theВ SE/30 boots up,В hence theВ Simasimac display. This is the photo of another SE/30В logic board вЂ“ click on it to view the high-res version:ДЄn educated guess would be that some of the data bits feeding into the video RAM were not having the correct values, probably due toВ broken PCB traces or vias resulting from the leak. Without going into the details, theВ schematics showsВ several 74F253 (4-input Multiplexer with Tri-state Output) connected to two D41264C (64K X 4 Video DRAM),В which is then connected to UK6, a 2764 serving as the video ROM. For a start, check out the SE30_P5.GIF fileВ for the video section.

#Mac se floppy emulator zip file#

The first thing to try was to download the logic board and analog board schematics of the SE/30 and many other similar compact Mac on this site.В They are in GIF format and not high resolution, but good enough to get me started.В You can also download a hosted ZIP file with all the schematics from here. Perhaps there is a common fault somewhere that can easily be fixed? But before that, my curiosity ledВ me onto a different path, that is to investigate why many SE/30 end up with the exactly sameВ Simasimacs screen, down to the pixels.

to remove all the leaky SMD electrolytic capacitors on the board and replaced it with new ones. The only thing I could do at this stage was a recap, e.g. TheВ same symptoms persisted even with all the RAM, ROM and video ROM removed, so it was probably not a problem with the ROM or RAM as mentioned on the website. The checkerboard pattern was no longer shown, instead I experienced the classic Simasimac screen asВ described here: On the next attempt to power on the machine, the symptoms changed.

I removed the battery, cleaned the motherboard thoroughly andВ soldered in a new 3.6V battery purchased from eBay: I opened up the case and immediately found out aВ potential cause вЂ“ the 3.6V PRAM lithium battery has leaked all over the place: Unfortunately my SE/30 has refused to boot up, showing the notorious checkerboard screen, after having been powered off for a couple of years: The Macintosh SE/30 is probably the most wanted Compact Macintosh computerВ due to its variousВ upgrade options, especially the ability to support up to 128MB of RAM with the right SIMM configuration.