Repairing and Rejuvenating an Apple Lisa 2/10 (Macintosh XL)
Ah Lisa, Lisa, Lisa. Why do you cause me so much pleasure and yet so much grief? I'm sure it's no coincidence that this machine has a feminine name.
Having worked hard to get one of my Lisa 2s up and running it was time to turn my attention to the second one of the haul, a Lisa 2/10. Unlike the first, this Lisa had retained its original colour so wasn't required to suffer the indignity of a full undress/disassemble for the retr0brite treatment. Even so, this old girl wasn't well.
Figure 1. The Apple Lisa 2/10 prior to restoration. Looks good, but multiple issues existed
The details follow. As I worked through this project I received lots of help from the guys on the Classic Computer mailing list (firstname.lastname@example.org) which I'd like to acknowledge here. Thanks guys! Your input was greatly appreciated.
When I first examined the computer, it threw up a memory error, meaning one of the two 512k boards was faulty. I soon found which one and swapped it out with a working board from my third "junk" Lisa. An easy fix.
After that, the machine managed to get through to the I/O board check but then crashed with an "Error 57" message. Looking this up in various docs showed this message meant the disk controller had a fault somewhere. Somewhere, but where? The fault could either be on the CPU board or somewhere on the widget hard drive boards? There was another odd thing. The ROM used for I/O work reported version H/EA? It should have been H/88 in the Lisa 2/10.
First thing was to reseat all socketed chips. No change.
The error occurred whether or not the widget drive was attached. This made me think it was something on the board itself. It could be any one of the logic chips, the 6540a controller chip, the IWM (integrated WOZ machine) or the ROM chip. Or maybe something else entirely. I had a spare 6540a controller chip so I swapped that out. No change. I had a scope and checked the pins of the major chips. Nothing appeared stuck. I also checked ALL the logic chips on the board. They were all doing what they should.
Figure 2. Checking the I/O board for stuck logic pins
Suspicion now lay heavy on the IWM and ROM. I was convinced one of these was the culprit. Unfortunately I didn't have any spares to check. FORTUNATELY I knew someone who did!
Figure 3. The IWM (left) and the I/O ROM (right). Strong suspects for the problem
The I/O board definitive diagnosis
Philip Lord (aka Nama) is a kiwi vintage computer aficionado who owns a Lisa or two. We've gotten to know each other quite well in forums and via email. As luck would have it, Philip was returning for a family visit to New Zealand from his country-of-residence Japan. He offered to call in and see me bearing both a IWM and a ROM from his 2/10 so we could swap them out. When Philip arrived we did just that. No change with the ROM, but with the replaced IWM the machine passed all checks. YES!!! I/O board problem diagnosed! What's more the ROM now reported H/88 as it should!
Now having identified the errant IC, the problem was to find a replacement. This chip is found in the early Mac models and also the Apple IIGS. I asked around in our local forum for anyone who had a junk board I could swipe one off. Fortunately someone volunteered one. Gavin Picknell (gavo), who originally sold me these three non-working Lisas, kindly donated one from an old Mac 128k board he had. Many thanks Gavin! The replacement worked just fine.
The floppy drive issue
I'd cleaned up the Sony 400k 3.5 inch floppy drive even before I'd started serious work on the 2/10. Sticky drives are common with old Lisa 2s and it doesn't hurt to give them a good clean before shocking them out of retirement.
With the Lisa passing all checks, I left the widget unplugged and tried to boot off this cleaned and regreased floppy drive. Hmm..the floppy drive didn't spin the disks. Actually it did spin the disk, BUT only if the spindle was in certain positions prior to a disk being inserted? Then it managed to load software..but only sometimes and very slowly. Clearly there were a lot of read errors going on.
After A LOT of investigative work (assisted by Tony Duel of the Classic computer mailing list) which included replacement of the TA 7259 motor IC and associate capacitors the problem still persists. Tony feels the fault lies within the spindle itself with the hall-effect devices. Interestingly the 400k drive from the parts-only Lisa (my third Lisa) has the same problem!
Figure 4. The Sony 400k 3.5 inch drive showing the components replaced during repair attempt
I decided to kick for touch with this one. I simply swapped out the drive from my recently fixed Lisa 2. Robbing Peter to pay Paul I know, and I'm eventually going to have to either replace the hall-effect devices or source a new drive from somewhere if I want TWO working Lisas. It was the 2/10 that I really wanted as my showpiece Lisa though.
The Widget issue
So, now the Lisa could boot from the floppy without issue. Not so the hard drive though. The computer would try to access the Widget but stall with an "Error 82". If I tried to install software on the drive, it would make a valiant attempt, but then say a suitable drive was not available. Error 82 is a very generic message which simply means the drive is not working properly. It certainly spins up? Reading around, my conclusion was that the hard disk needed a low-level format. Trouble is, there seems to be no way to do this for Widget drives!
Figure 5. The mighty Widget
A Widget replacement. The X/Profile emulator
Philip Lord not only bought over I/O chips to swap out, but he also introduced me to his IDEfile, a Lisa ProFile emulator. This device emulates a ProFile drive, an external hard drive that is normally hooked up to a Lisa 2/5. Software can be kept on CompactFlash cards or an IDE drive. We hooked this up to my working Lisa 2. I was impressed! It worked just fine. I was equally impressed by the Lisa Office Suite. For 1983, it was WAY ahead of it's time.
Given that widget repair was impossible, I decided the best way forward was to replace it with a IDEfile or a device like it. Someone on the Classic Computer mailing list put me onto the latter. This was an updated board similar to the IDEfile but one which could be a direct replacement for the Widget and well as a ProFile drive. It was called the X/ProFile, produced by John Woodall and he was selling the boards on e-Bay. At $US 370 it wasn't cheap but for a Lisa, it was worth it to me. I wanted something "plug-and-play" that I could just install to get the Lisa Office suite up and going straight away. It seemed to fit the bill.
Figure 6. X/ProFile card mounted in the drive bay
And indeed it did. I am VERY happy with it. Manuals were easy to follow, the workmanship was top notch and installation was a breeze. It's now mounted in the case where the widget was, and boots the Lisa Office suite (or MacWorks XL if I so desire) from a FlashCard.
The keyboard issue
Before I even started working on this Lisa I knew that none of its keys worked. However, that problem was fixed with replacement pads as detailed in the article on the first Lisa 2 restoration (which had the same problem, as did the keyboard attached to the third Lisa!).
This Lisa 2/10 might have looked ok, but it had multiple problems. These included:
- The PSU needed new filter capacitors (I didn't mention this did I)
- A non-working keyboard
- A faulty 512k memory board
- A faulty IWM IC on the I/O board
- A non-working floppy drive
- A faulty (unrepairable) Widget drive
Actually there was more. When Philip Lord and I were working on the machine, a memory board failed. It could have been the replacement board, or the other original one. Luckily I had one more spare from the 3rd Junk Lisa.
Figure 7. The Lisa 2/10 now fully operational, showing the Lisa Office Suite
Getting this Lisa 2/10 up and running has been a mission, and in fact the whole Lisa project is not quite finished. I need to either fix or get a replacement drive for my Lisa 2 before I can say both my ladies are without fault.
However, I'm happy. I now have one very handsome Lisa 2/10, now fully working albeit not in its original state. Without the noisy swish and vibration of the Widget it's not quite the same. It's bound to be far more reliable though!
5th March, 2011
P.S. I've since managed to repair those faulty memory boards!
P.P.S I've now acquired a working floppy drive for the Lisa 2 I "borrowed" from!