Hi Josh, whow, seems it's my lucky day :) - thanks a lot for the offer!
> On 14 Sep 2020, at 18:00, Josh Dersch <dersc...@gmail.com> wrote: > > I've restored a Star/1108 (and wrote a Star emulator) and am in the middle of > an Explorer restoration, I'm happy to help out where I can. > > I'd recommend picking up an MFM Emulator (https://www.pdp8.net/mfm/mfm.shtml) > along with the SA1000 adapter for same, for use with the Star. The original > disks are getting more difficult to keep running, and it's also a lot more > convenient for switching between different operating systems, etc. That's definitely a good idea - and good to know that the disks are simply MFM and not some more exotic standard such as SMD. > Remove the sound-deadening foam from the panels of the system, it's getting > crumbly and isn't going to do you any favors to leave it in place. Yeah, I remember the TI1500s also had that problem and the stuff is pretty nasty. > I've found the power supplies to be fairly reliable. Good to know - analog power electronics is not really my area of expertise, but we have a competent electronics department nearby that can probably help just in case. > One issue is weak picture tubes in the displays -- the monitors are powered > on with the system and have no separate off switch, so they tended to get a > lot of hours put on them. We had good luck with a tube rejuvenator on the > one we restored at LCM. Yes, the picture seems to be burnt in quite a bit in all of the displays (we have three systems here). Not sure if I can find a tube rejuvenator here in Trondheim, but you never know. > The Star mouse pad can be recreated with a laser printer (I've used this: > http://www.digibarn.com/collections/devices/xerox-mousepad/index.html, and > there's a postscript file floating around out there...). Or any surface with > a fine pattern on it seems to work pretty well; I was able to make it work on > a speckled countertop and the pant leg of my jeans at one point. It's a lot > more forgiving than the Sun mice which need the fixed grid of the metal mouse > pads. Great, thanks! > For the Explorer, there are a number of r fa line filter caps in the system, > on the power supply board as well as on a separate board near the rear of the > chassis. I suggest replacing these immediately as they like to let out smoke. Good to know, I'll take care. The roller-type fans (hope that's the correct English term) also made some problems at least on the large TI1500 system back in the '90s, the Explorer should use the identical chassis. > The optical cable is extremely rare and despite some valiant efforts we > haven't found an equivalent, or new-old-stock replacements. A friend of mine > is working on retrofitting modern optics, and has made some great progress. It seems that the TI931 terminals also had a fiber optics option and used the same cable (http://bitsavers.org/pdf/ti/terminal/crt/2229228-0001A_Model_931_Video_Display_Terminal_General_Description_Dec83.pdf) - but I've never seen a 931 using that option. So that won't make the cable easier to find. > The mouse is indeed a standard Mouse Systems, I'm missing mine at the moment > and haven't yet gotten to the point of adapting a mouse to replace it. I > suspect it's equivalent to the M2 used on the Sun-2 and LMI Lambda systems. Hm, on some photos I found the Explorer mouse looks identical to the Sun-2 mice (black case with white buttons). However, the Sun-2 (just checked the schematics on bitsavers) already used a serial interface (via a Z8530 SCC) to connect to the mouse, the Explorer (see my other post with the pinout I found) seems to use quadrature encoding. But maybe there have been different options for the Explorer. > Media for the Explorer is another question that I'm hoping to answer soon. > There are disk images from the Meroko emulator but my understanding is that > they are incomplete. Bitsavers has QIC tape images but I have yet to try > them. The interface on the Explorer is SCSI but I haven't had luck booting > it from a SCSI2SD w/Meroko images loaded. The disk boxes contain an Emulex > SCSI->MFM bridge, so use of Dave's MFM emulator might make sense here as well. I think the firmware on the NUPI-2 NuBus disk/tape controllers (this has its own 68000 CPU) speaks a pre-standardisation SCSI protocol variant (something closer to the original SASI, I think). The TI1500 used Imprimis/CDC WREN 670 MB disks (probably WREN VFH 94181-702) by default IIRC - and those were the only disks (of that size) that worked reliably on the 1500. I assume the NUPI-2 in the Explorer is identical, so that might be the problem with SCSI2SD. We have a number of the disk enclosures, so I hope that some of the disks still work. > If you have disks in your Explorer, let me know -- capturing an image of > their contents would be extremely useful, and the original Maxtor drives are > not long for this world. We have four machines with drives, I'll definitely do an image of all of the disks first and will also check if I can find some install tapes. > Hope that helps a bit, happy to answer any questions... or try anyway. Thanks a lot - the machines will definitely keep me busy in the upcoming rainy weekends and evenings... Best wishes, Michael
