4 Feb
2007
4 Feb
'07
8:27 a.m.
From: Liam Busey <buseyl at yahoo.com>
But for me the
biggest problem was
that the Apple couldn't read/write disks from other
machines, unlike the
TRS-80, which used a WD1771 controller and could
handle any single-desity
5.25" disk (I spent many late nights getting it to
read the disks from
the school's RML380Z computers, which also used 1771
controllers).
To be fair though, the Apple Disk II system was not
the only game in town. While they weren't common, you
could get a 3rd party 8" MFM floppy system if you
wanted to. 
4 Feb
4 Feb
1:05 p.m.
At 08:27 AM 2/4/2007 -0800, you wrote:
Lobo Drives made drives for, among others, the Apple II including a neat box
I used to sell and service Apple ][ computers. For a while there, the
biggest service issue we had was with people bringing in their floppy
drives (single 5.25 inch) and saying we'd sold them a bad one, or it died
under warranty.
Before even letting the customer leave the premises, I'd quickly take out
the four screws that held on the cover and show them the blackened spot on
the inside of the cover, then show them the 74LS125 in the middle of the
board, which invariably had been cracked or cratered.
The documentation clearly said, connect the ribbon cable to the controller
with the cable exiting AWAY from the board. But there were any number of
folks that went the long way around, and put a great deal of effort into
bending the cable sharply where it exited the ID connection, so that they
could plug it into the controller card backwards.
This usually resulted in a spectacular failure of the '125.
I had to tell them that Apple had designated this a special case: No
warranty if you let the smoke out.
I saw some with a neat crater in the chip, and a scorch mark inside the
cover aligned with it.
-T
[Commentary] And, of course, the word "politics" is derived from
"POLY", meaning many, and "TICS", meaning small, blood sucking
insects. --Chris Clayton, USFMCNCG at ibmmail.com
--... ...-- -.. . -. ----. --.- --.- -...
tpeters at nospam.mixcom.com (remove "nospam") N9QQB (amateur radio)
"HEY YOU" (loud shouting) WEB ADDRESS http//www.mixweb.com/tpeters
43? 7' 17.2" N by 88? 6' 28.9" W, Elevation 815', Grid Square
EN53wc
WAN/LAN/Telcom Analyst, Tech Writer, MCP, CCNA, Registered Linux User 385531
From: Liam
Busey <buseyl at yahoo.com>
But for
me the biggest problem was
that the Apple couldn't read/write disks from other
machines, unlike the
TRS-80, which used a WD1771 controller and could
handle any single-desity
5.25" disk (I spent many late nights getting it to
read the disks from
the school's RML380Z computers, which also used 1771
controllers).
To be fair though, the Apple Disk II system was not
the only game in town. While they weren't common, you
could get a 3rd party 8" MFM floppy system if you
wanted to. 
3:56 p.m.
On Feb 4, 2007, at 4:05 PM, Tom Peters wrote:
Before even letting the customer leave the premises,
I'd quickly
take out the four screws that held on the cover and show them the
blackened spot on the inside of the cover, then show them the
74LS125 in the middle of the board, which invariably had been
cracked or cratered.
The documentation clearly said, connect the ribbon cable to the
controller with the cable exiting AWAY from the board. But there
were any number of folks that went the long way around, and put a
great deal of effort into bending the cable sharply where it exited
the ID connection, so that they could plug it into the controller
card backwards.
This usually resulted in a spectacular failure of the '125.
Did that failure take out anything else, or did replacing only the
74LS125 solve the problem?
-Dave
--
Dave McGuire
Port Charlotte, FL
4:10 p.m.
At 06:56 PM 2/4/2007 -0500, you wrote:
On Feb 4, 2007, at 4:05 PM, Tom Peters wrote:
It's been along time-- The one or two times I attempted component level
repair, I can't remember what the result was. We did a swap on the board
and the customer had to pay for it.
Before even letting the customer leave the
premises, I'd quickly
take out the four screws that held on the cover and show them the
blackened spot on the inside of the cover, then show them the
74LS125 in the middle of the board, which invariably had been
cracked or cratered.
The documentation clearly said, connect the ribbon cable to the
controller with the cable exiting AWAY from the board. But there
were any number of folks that went the long way around, and put a
great deal of effort into bending the cable sharply where it exited
the ID connection, so that they could plug it into the controller
card backwards.
This usually resulted in a spectacular failure of the '125.
Did that failure take out anything else, or did replacing only the
74LS125 solve the problem?
-Dave --
Dave McGuire
Port Charlotte, FL
Keeping in touch with childhood memories keeps us believing in life's
simplest pleasures like a rainy afternoon, a swingset, and a giant
puddle to play in. -- Chrissy Ogden
--... ...-- -.. . -. ----. --.- --.- -...
tpeters at nospam.mixcom.com (remove "nospam") N9QQB (amateur radio)
"HEY YOU" (loud shouting) WEB ADDRESS http//www.mixweb.com/tpeters
43? 7' 17.2" N by 88? 6' 28.9" W, Elevation 815', Grid Square
EN53wc
WAN/LAN/Telcom Analyst, Tech Writer, MCP, CCNA, Registered Linux User 385531
4:48 p.m.
Dave McGuire wrote:
9 times out of 10, that was the only replacement required. If you were
unlucky, you might also lose the MC3470, but I only ever had to replace
about half a dozen of those.
--
Pete Peter Turnbull
Network Manager
University of York
On Feb 4, 2007, at 4:05 PM, Tom Peters wrote:
> Before even letting the customer leave the premises, I'd quickly take
> out the four screws that held on the cover and show them the blackened
> spot on the inside of the cover, then show them the 74LS125 in the
> middle of the board, which invariably had been cracked or cratered.
I remember it well :-)
> The documentation clearly said, connect the ribbon
cable to the
> controller with the cable exiting AWAY from the board. But there were
> any number of folks that went the long way around, and put a great
> deal of effort into bending the cable sharply where it exited the ID
> connection, so that they could plug it into the controller card
> backwards.
Or the right way round, but one pin displaced, sometimes.
This usually
resulted in a spectacular failure of the '125.
Did that failure take out anything else, or did replacing only the
74LS125 solve the problem? 
4:52 p.m.
On Sun, 4 Feb 2007, Marvin Johnston wrote:
Lobo Drives made drives for, among others, the Apple
II including a neat box
with an 8" floppy drive and an 8" hard disk. They were given to me to sell on
Ebay, and then the guy passed away (same person who gave me all the Poly stuff,
and lots of other things before he died.) I have them set aside until either I
have the time to find out more about how to hook it up, or someone drops by who
knows what they are doing. My suspicion is that the hard drives probably have a
lot of interesting things from Lobo Drives, hence my caution. And I *think* I
have the controller card, but again, I need to research this stuff out.
I have a Lobo 8" drive controller and (I believe) the software also. I
think it was one of the earliest A2 peripherals to use DMA and was
developed in the days of the II+. Mine never worked properly on a 2e
(don't recall if I tried it on II or II+).
Steve
--
6529
days inactive
6530
days old
5 comments
6 participants
participants (6)
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listmail＠athenet.net -
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