Drive protector card

[Raymond Carlsen]

Someone asked about the best way to store a drive. When I answered that
post, it started me thinking about how many users get their drives without
the transit card. It's just a cardboard square that comes with the new
drive, but it's important to use it when the drive is shipped. I've seen
way too many 1571's damaged by rough handling, so I thought it would be
beneficial for users to know how to make their own cards and protect those
precious drives. Here's how...

Make your own transit card for your 1541/1571 drives. 11-13-99

The transit card (sometimes called a "head vibration protector") that
comes with a disk drive is an important tool. The card is made of stiff
cardboard and is the same size as a floppy disk, except for the tab that
sticks out of the front end. That tab, unlike a disk, pushes the head
stepper mechanism back to track zero when the card is inserted into the
drive. In addition, when the drive door is latched down, the heads are
allowed to rest on the card and are therefore prevented from hitting each
other in the 1571 and clone drives. More importantly for the 1571, the
head lifter mechanism is released, so any physical shock to the drive will
not bend the head mount. This is very important when the drive is to be
transported or shipped! A scrap disk will protect the heads and mount, but
will not keep the stepper mechanism locked in place.
One use for the transit card is often overlooked. When a 1541 head
moves past track 18, the drive can become "lost" and fail to respond to
the computer. Some disk errors can do that, as can turning the drive off
before a program has reinitialized the drive. Even if turned off and on
again, the drive will appear nearly "dead". You can send an Initialize
command or format a disk to pull the head back, but a quicker way to
recover the "dead" drive is to turn it off, insert the transit card to
push the head back, remove the card and turn the drive on again. That
method does not require that the computer be turned off, so any program
running is not lost.
Early 1541 drives were shipped with a card, the CBM 251171-02. It
would fit only the 1541 because the tab was quite large, about 1.5" wide
and centered on the front of the card. A later version of the card, a CBM
251171-03 had a smaller offset tab, and was used in the 1571 drive. That
same card will work in a 1541 as well. I tested the later card in all my
5.25" drives and it fits and works with all of them. That includes the
1541 (both ALPS and Newtronics), the 1541-II, both versions of the
Amtech/Blue Chip (1541 and 1571 clones), the Excelerator (Oceanics) 1541
clone and the MSD SD-2 dual drive.
You can make your own card out of thick (not corrugated) cardboard or
plastic. It should be stiff enough so the tab does not bend when the card
is inserted, but not so thick (more than a floppy disk) that it will not
fit the drive. I will include the dimensions here. Note that the tab is
offset to the right slightly, unlike the early 1541 tab which was centered.
By the way, if you have one of the early cards, you can easily trim the tab
to match these dimensions. If you're making a card from "scratch", you can
use a disk as a template (but don't forget the tab). Once you have your
first card, you can use it as a template to make more.

Insert this end of card into drive.
tab depth = 7/8" or 2.2cm
.--------------.
| |
<--------- 2 1/4"----------->|<-- 1 1/8"--->|<------- 1 7/8" ------>
5.8cm | 2.8cm | 4.8cm
| |
.----------------------------' `-----------------------.
| |
| |
| |
| Card (less tab) measures 5 1/4" (13.4cm) square |
| (same size as floppy disk) |
| |
| |
| |
| |
| . |
| . . |
| Hole in center of card . |
| . . |
| |
|<----- 1 7/8" ------>.<-- 1 9/16" diameter -->.<----- 1 7/8" ----->|
| 4.7cm 4cm 4.7cm |
| . . |
| . . |
| . . |
| . |
| ^ |
| | |
| | |
| | |
| 1 7/8" |
| 4.7cm |
| | |
| | |
| | |
| V |
`-------------------------------------------------------------------'

Ray Carlsen
CARLSEN ELECTRONICS... a leader in trailing-edge technology.

[Joe Forster/STA]

Hey Ray, way cool an idea... 8-) Anyway, since not all of use read this
newsgroup with an ASCII-based NEWS reader, could you post that drawing
in GIF format? Or, since binary stuff is not welcome here, put it up
somewhere on the Web? Thanks!

Joe Forster/STA
s...@c64.org

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[Sharuq]

Actually, someone could just copy the text into a program such as notepad
(windows) or simple text (Mac) and the text image will display just fine.

> Hey Ray, way cool an idea... 8-) Anyway, since not all of use read this
> newsgroup with an ASCII-based NEWS reader, could you post that drawing
> in GIF format? Or, since binary stuff is not welcome here, put it up
> somewhere on the Web? Thanks!

Commodore will rise again to rule the world!!!
"Real programmers never die. They just GOSUB without RETURN."

[Joe Forster/STA]

Good idea, Sharuq! It's just that you need to cut that text from the
_source_ of the HTML page... (I'm use RemarQ, a _Web-based_ NEWS
reader site, you know.)

[Nicolas Welte]

Joe Forster/STA wrote:
>
> Good idea, Sharuq! It's just that you need to cut that text from the
> _source_ of the HTML page... (I'm use RemarQ, a _Web-based_ NEWS
> reader site, you know.)

Joe, I don't know about RemarQ, but Dejanews has a special button that
shows the "original Newsgroup format" of the message, which is just the
plain ASCII version. What a luck we have a decent NNTP feed here ;-)

Nicolas