[comp.sys.apple] Disk ][, Apple //c, HELP!!

CYLau@UNCAMULT.BITNET (The Ultron) (04/30/89)

 Help!!  My //c is acting up..  The stupid machine won't shut off the
drive..  it will read and write properly but not shut the drive off when
it's finished..  I suspect the IWM chip, but I'm not absolutely sure.

 Can someone with more expertise in the hardware of this thing tell me
if my suspicions are true, and about how much it would cost to get it
repaired??  (so, it's my first EVER problem with an apple...  I don't
know how much a repair on it costs :-) ) Also, is it possible, if the
problem is the IWM, to get a new one ANYWHERE??  illegal or legal (my
machine has been off warranty for the last few years...  so I don't
care, as long as I can get it running again..)

 My second question has to do with an old Apple disk ][ unit I got from
a friend...  I think it's severely out of alignment, but there might
also be a problem with the head..  the problem is, I can't tell which
because I can't even boot from it..  it calibrates to track 0, and then
keeps spinning...  I tested it on my //c (before I blew the IWM) and it
kept running until I put a disk in the drive, then it said "Check
Disk"...  I wasn't aware that an ext.  drive was supposed to do that..
my internal doesn't do that...  but it seems to suggest that my r/w head
is ok...  if so, what is the procedure to align the bugger?  (I don't
trust the repair shops with this simple procedure..  the last time I
brought a drive in, they charged me $40 and said it was fine...  I
tested it with the diagnostics again and it said that nothing had
changed..  I brought it back and they charged me another $25 just to
look at it again...  Needless to say, I wasn't pleased...  I got my $$
back and took the drive to a friend, (who alas, has moved away since
then) and he aligned it for free) So if possible, I'd like to try
aligning it myself...  not only to save $$ and time and frustration et
al.  but to learn something about it myself..

 Please Email any replies, unless you think others on the net would also
be interested.

Thanks in advance
Chris



+----------------------------------+      +----------------------------------+
!   Christopher Lau                !      !  COGITO COGITO, ERGO COGITO SUM  !
!   The University of Calgary      +------+    "I think that I think;        !
!   CYLau@UNCAMULT.BITNET          +------+     therefore, I think I am."    !
!   CYLau%UNCAMULT@MITVMA.MIT.EDU  !      !        - Ambros Bierce           !
+----------------------------------+      +----------------------------------+

ewsmith@uokmax.UUCP (Edward Warren Smith) (05/01/89)

In article <890430153927.040595@UNCAMULT.BITNET> CYLau@UNCAMULT.BITNET (The Ultron) writes:
>problem is the IWM, to get a new one ANYWHERE??  

The IWM is Apple Part Number 342-0041 (for the //c) and is available
for $29.00 ($19.00 if ordering 10 or more) from:

Pre-Owned Electronics, Inc.
30 Clematis Avenue
Waltham, Massachusetts  02154

(800) 274-5343   (Orders; voice only)
(617) 891-6851   (Technical help; voice only)
(617) 891-3556   (Fax only)

They warrant everything they sell for 90 days and take Visa, MasterCard, or
COD.  The single-sheet catalog I have before me doesn't mention minimum orders
or their personal check policy.

In my dealings with them I have found them excellent; the salesmen I spoke with
were well aware of the technical points of the custom chips and the roles the 
parts played in their particular machine.

As for the parts themselves, they sent me new (versus pull-out/reconditioned)
ICs.

>Thanks in advance
>Chris
 
My Pleasure; thank you.
Ed

matthew@sunpix.UUCP ( Sun NCAA) (05/01/89)

In article <890430153927.040595@UNCAMULT.BITNET>, CYLau@UNCAMULT.BITNET writes:
> 
>  Help!!  My //c is acting up..  The stupid machine won't shut off the
> drive..  it will read and write properly but not shut the drive off when
> it's finished..  I suspect the IWM chip, but I'm not absolutely sure.

If your problem was on an older Disk ][ controller card I'd say the problem 
was the 555 timer on the card that keep the drives spinning for a second or
two after being turned off (keeps the drive spinning during very short off time
to reduce startup time if your software makes a lot of quick accesses).  A look
at the Apple //c schematics show that the Apple //c drives are controlled from
the IWM, so I assume this function of the Disk ][ controller was also incorporated
into the IWM

> Also, is it possible, if the problem is the IWM, to get a new one ANYWHERE??

IWM are available from a few sources selling Apple original parts. I believe 
the selling price of a IWM is $29.  Computer Shopper is your needed source of info 

> I tested it on my //c (before I blew the IWM) and it kept running until I put 
> a disk in the drive, then it said "Check Disk"...  I wasn't aware that an ext.  
> drive was supposed to do that..  my internal doesn't do that...  

I've never heard of an external drive doing that either, but your internal drive
is suppose to do that after a number of retries at reading track 0/sector 0.
turn on your //c without any disks in any drive. You'll see what I mean.



-- 
Matthew Lee Stier                         |
Sun Microsystems ---  RTP, NC  27709-3447 |        "Wisconsin   Escapee"
uucp: { sun, mcnc!rti }!sunpix!matthew    |
phone: (919) 469-8300 fax: (919) 460-8355 |

CYLau@UNCAMULT.BITNET (The Ultron) (05/02/89)

*Date:  Monday, 1 May 1989 09:38 mdt
*From:  Sun NCAA <rti!sunpix!matthew at MCNC.ORG>
*Subject:  Re: Disk ][, Apple //c, HELP!!

*In article <890430153927.040595@UNCAMULT>, CYLau@UNCAMULT.BITNET writes:
*>
*> Also, is it possible, if the problem is the IWM, to get one ANYWHERE??

*IWM are available from a few sources selling Apple original parts. I believe
*the selling price of a IWM is $29.  Computer Shopper is your needed source of
*info

Yes, thank you for the info, the Apple "rip-off artists" (read Authorized
Dealers :-) ) up here wanted to replace the whole motherboard for around $300
which is around $300 too much, considering that for $400-500 I can get another
//c (used of course) with a monitor, software etc..  And since my warranty has
long since expired, I have no problems about going in and fixing it myself..


*> I tested it (before I blew the IWM) and it kept running until I put a disk
*> in the drive, then it said "Check Disk"...  I wasn't aware that an ext.
*> drive was supposed to do that..  my internal doesn't do that...

*I've never heard of an external drive doing that either, but your internal
*drive is supposed to do that after a number of retries at reading track 0,
*sector 0.  Turn on your //c without any disks in any drive. You'll see
*what I mean.

I know that my internal drive causes the system to display the "Check disk"
message when there is a blank or no disk in the drive...  what happens is that
an old Apple disk ][, connected as the //c's external drive, when PR#7 is
used to boot (I've got the old ROMS) with no disk in the drive, will keep
running indefinitely (no message), until you put a disk in the drive, then
it will boot, if possible, else display the "Check disk" message... strange..
is there something different about the //c drives and the Disk ]['s besides
being smaller??


*--
*Matthew Lee Stier                         
*Sun Microsystems ---  RTP, NC  27709-3447         "Wisconsin   Escapee"
*uucp: { sun, mcnc!rti }!sunpix!matthew    
*phone: (919) 469-8300 fax: (919) 460-8355 



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