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Re: wtb: original apple ][ broken as-is for parts
Tristan Mumford wrote:
Liam Busey wrote:
Tristan Mumford wrote:
I'm not after you rotten ][. My moldy ][+ would get jealous. ;)
I got given the ][ in '99 (i think) after a cheap secondhand notebook I
purchased violently exploded. Ex Telstra equipment. They replaced a NiCad
clock battery with a big lithium. As we all know they don't like being
charged.
Ah--"murder by repair".
That's the price of not learning history (or looking it up ;-).
Your service tech clearly didn't "get" NiCads.
Well there are masked ROMs, a character generator, and a keyboard
encoder but those can all be worked around.
The biggest issue with the II/ II+ is that for some reason Apple
decided to socket ever single chip on the motherboard (IIRC ~120
chips). While on the surface it may seem to be very convenient for
repairs, every one of those sockets is a weak or intermittent
connection waiting to happen. On a well kept machine this is no
problem. On a machine that's been sitting in someone's basement for 25
years, well .... AARRGHHHHH!!!!!! Tarnished chips and sockets are a
PITA!
Try a leaky shed for 6 years.
I'm going to do a reseat anyway.
The main issues are the floppy drives and a blown resistor on the mainboard.
The floppy drives instantly scratch the life out of disks. And as for the
blown resistor, I don't recall where it was. I just know it made operation
a little unstable.
Leaky shed for six years opens up a lot of possibilities!
Corrosion and corrosion by-products should be your biggest
worry. A complete wash followed by a complete rinse with
clean (distilled?) water, or even a final alcohol rinse (not
rubbing alcohol--too much oil) sounds in order. A toothbrush
will be handy, maybe even a dishwasher!
Allow boards to dry *completely* (at least overnight if just
drip-drying) before applying power.
After cleaning, examine the boards carefully for any traces that
are either corroded away or shorted by corrosion. Ditto any
socket contacts--especially near the board where it's almost
impossible to clean. ;-(
Sounds like the heads on your drives need to be not just cleaned,
but burnished to remove "rust"--but nothing scratchy. I'd take
them apart (checking the lubrication in the process) and burnish
the heads with cardboard or a Dremel cloth wheel (carefully, so
as not to fold them ;-).
Since you are experiencing some degree of operation, the cleaning
will probably get you to reliable operation.
Glancing at your website, you seem to be the tinkering type. Old Apples
are great for that. They're simple and very open. There's a book called
"Understanding the Apple 2" by Jim Sather that describes the Apple II/
II+ circuit in detail. It's very popular with this newsgroup. You can
find a PDF of it in the Apple manual section of http://1000bit.org.
There's also a wealth of interfacing books for the Apple but
unfortunately most haven't made there way online yet.
Couldn't agree more--you can field-strip an Apple ][ in 20 minutes. ;-)
Thankyou for that morsel of information. Very useful indeed.
I am the tinkering type. Always have been.
My site is out of date right now. My project hit a dead end. A fault I can't
diagnose with my equipment. I'm going to redo the board from scratch. The
wiring is right, but something isn't working as it should be.
I'm thinking of doing a version of the original adaption of the MicroUSB
board for apple2 on a single board.
Latest stupid idea:
Apple2 on wrong end of house to connect using wired network easily. Why not
USB bluetooth?
I thought Bluetooth was for a room or two, not whole houses...
But with all the neat wireless stuff we have these days, it would be
cool if someone would use them to connect an Apple wirelessly...to
a modern machine or to another Apple II. ;-)
I've thought about a wireless link for NadaNet, but I need a few hundred
kilohertz bandwidth, and that seems either UHF/microwave or illegal.
(I also need a pretty noise-free channel...maybe infrared... ;-)
-michael
NadaNet networking for Apple II computers!
Home page: http://members.aol.com/MJMahon/
"The wastebasket is our most important design
tool--and it's seriously underused."