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Where great old Macs live again!

So almost 2 years after i got my first Lisa, I've finally done something about getting them running.

You have to remember, 26 - 27 year old components are a bit temperamental, and I've had to do my fair share of electrolytic replacements in the Lisa and Profile power supplies, as well as the voltage regulator repairs I'll speak f another time.

So what's new I have learned this weekend,

a) At memory address line 240, the first 20 characters represents the serial number of the machine. There is a special way of decoding the serial number by removing every second digit, stripping the FF's and you end up with YY DDD SSSS where YY is year, DDD is day of the year and SSSS is the unique serial number (I dont know how unique we are talking here, if its day or year based)

I did learn that I have a CPU board out of a Lisa Made and serial plated in 1982 - This was before the lisa was released.... And was in a machine I have thats clearly a Lisa converted to a Lisa II (Yes, everyone cry for me)

b) Lisa OS CAN run on a Macintosh XL with screen modification kit installed - However you will just get a completely unreadable screen as all the lines are offset an inch the whole way down the screen in a slanted pattern

c) I have two I/O Boards with what i believe to be the less common "F" type roms, over the H roms.

d) All 4 of the keyboard I got with the lisa's are stuffed. They all need to be reworked for foam pad deterioration which is a royal pain and can take a whole day to get one keyboard fixed.

e) 400KB Disk drives - They are terrible, unreliable, a felt pad to apply pressure to the top half of the disk, oh no, that doesn't sound like a recipe for disaster.... NOT

f) My original widget that was dead in my Lisa 2/10 could not be resuscitated. The original fault that was caused by a bad "SERVO" board has transcended into something wrong with the disk heads or surface. This may or not have something to do with me opening it up in frustration in the first place before I had another widget to steal parts from to test, Alas, It had gone to a better place.... actually thats a lie, its sitting on the floor in my room as spare parts from my XL Widget.

g) On a totally unrelated topic, another disk in my collection for a scanner has Andy Hertzfeld's signature on it.. Th other item i have is a Macintosh Manual.. I've come to the conclusion that these were not signed as a favour or gift, but as Andy's personal items.. Simply, why would you sign a random scanner disk, and not get someone to sign your actual Mac disks etc???

h) Its really really expensive to fix gold fingers on a board. One of the Lisa IO boards I have is stuffed. The fingers have been damaged by a leaky NiCad battery pack at some point, where a few of them have come clean off the board.. I found a place called circuitmedic, but for $79USD for a tiny pack of fingers, I don't think so, but looking at there stuff, for the connoisseur of circuit repair, jackpot...

i) I should go to bed, as I need to wake up and do some real work and pack away the lisa's until I can play again

j) There is these magnets glued to the neck / collar of the Lisa CRT positioned at factory to place the beam cut off.. One of my Lisa's monitor was a bit funky, all the glue had melted and they'd been spinning around. I span the back and 92% voila, not perfect but better. I also learned after a recent acquisition of some Lisa technical documents that there is 4 different strength magnets available to place on the colar to fix the beam landing, my had red stripped ones. There is 4 different strengths, I believe the red are the lowest grade

k) I'm almost due for an electric shock, its been a while, but I've been a good boy with my hand behind my back while playing with the CRT's

KIDS don't stuff around with CRT's or HV circuits, they are nasty, I can vouch for that.. (recall iMac G3 analogue board discharging its HV circuit in my hand when I pick it up of my bench... You CAN'T throw off a 10Kv discharge when it makes your hand clamp to the board tighter...)

Anyway, more to come

Views: 11

Tags: CRT, Electrolytics, HV, Lisa, Profile, Safety, Widget

Comment by macdownunder on April 12, 2009 at 10:32pm
Hey Macmedic,

I have quite a few widget drives that need help in Melbourne. If you're interested in free parts in exchange for some repair work let me know!

BTW: If you thought the 400k drives were bad - you should see the twiggie drive mechanisms!
Comment by macmedic on April 13, 2009 at 3:05am
Hey, that would be awesome, maybe we can do some repair work for each other.. I am very savvy with power supply repair of the AC electrolytics in the Profile and Lisa's as well as everything in between... Also, Im looking for a Analogue board for a Profile 10MB version, the analgue board being the controller board on the Actual hard disk, I have 3 or 4 10MB Drives (One which was brand new) and the controller boards, but it seems the Analogue board/s i have for them are Dead,
Comment by macdownunder on April 13, 2009 at 3:51am
No worries. I'll have to get my Profiles out and test them all (again). I know I have 1 x 10Mb Profile which came with an Apple // 10Mb Profile card and all worked on arrival. But that was a few years ago now.

As for the others, most were 5Mb - some DOA which I will need to check.

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