Forum unknown
· Hardware
#3.5 Disk drives
5 messages in this thread
I saw your message about drives and I thought I would pass along some of what
I know so far about Amiga drives. All drives are not created equal! Drives
for the Amiga must be able to do two things most (The ones I looked at
anyway) drives do not.
#1 They must be able to send "DISK CHANGED"
#2 They must be able to latch the "MOTOR" signal. The part number on the
Amigas external drive is P/N 134-100678-008-0
And by the way both the internal and external drives that I looked at were
NEC. Two things I hated about the way Amiga did the drives was using those
&#$!! "cute" DB23 connectors and making the drive control signals funky. I
know they have reasons for not liking the standard arangment. I hate it too!
But still who wants to pay $300.00 for a crummy $75.00 drive? Oh I forgot to
mention the other particulars are 80 track double sided double density. If
you do buy those bargan disk drives and they don't have the extra signals be
prepared to do some soldering.
It might interest you to know that the external drive has a "Paddle board" to
latch motor (I Think) and provide termination for some signals. Who thinks
up this ….Stuff? Oh well when I get the last bug out of my home brew
external drive I'll drop another note. Right now it only works if you don't
change disks. ie no "DISK CHANGED" signal……… YET!
Thanks, I took my external drive appart this weekend and found an NEC FD1035
which seems to conform to the standard for double sided 3.5 in. drives 95mS
access 250 Kbits/sec Xfer rate.
I also saw that little board that I figured at least latched the disk change
although reading my Tech Ref Manual intuition likes it but does not need it.
But to keep the standard I feel that all other drives should support.
Do the 5 1/4 inch drives also have to latch these two signals?. I did not go
so far as to take out the little "Paddle board" and attempt any reverse
engineering. I imagine that soon others will do so and we will see Amiga
Compatible drives on the market for $150-$200.
As soon as I get a cheap hard drive less than $1000 for 20MB fast access (my
personal max) the second drive will most likely be sold to someone operating
on a budget. It is nice to know that the drives in there are standard and can
be replaced for less than the cost of a service contract on them. (if they
break throw them out or sell them to a student cheap and replace yours with a
new one) Another sad commentary on our throw away society.
I guess Im not sure about the 5 1/4 inch drives as far as do they need to
send out diskchanged. My guess is that they do if for no other reason then
to limit the second source people to those who can spend the time to figure
out the changes. I was able to get away without latching motor. I just
wired it on and the drive worked as far as could be expected. However the
lack of a diskchanged signal throws the OS when you do change the disk and it
doesnt get clued in. As far as Hard disks go I think prices will come down
enough to make your $1000.00 wish come true. I just hope some body comes out
with a nice SCSI output port so you can choose your own drive! Gota go thanks
for the message. Jay
I guess Im not sure about the 5 1/4 inch drives as far as do they need to
send out diskchanged. My guess is that they do if for no other reason then
to limit the second source people to those who can spend the time to figure
out the changes. I was able to get away without latching motor. I just
wired it on and the drive worked as far as could be expected. However the
lack of a diskchanged signal throws the OS when you do change the disk and it
doesnt get clued in. As far as Hard disks go I think prices will come down
enough to make your $1000.00 wish come true. I just hope some body comes out
with a nice SCSI output port so you can choose your own drive! Gota go thanks
for the message. Jay
Thanks, I took my external drive appart this weekend and found an NEC FD1035
which seems to conform to the standard for double sided 3.5 in. drives 95mS
access 250 Kbits/sec Xfer rate.
I also saw that little board that I figured at least latched the disk change
although reading my Tech Ref Manual intuition likes it but does not need it.
But to keep the standard I feel that all other drives should support.
Do the 5 1/4 inch drives also have to latch these two signals?. I did not go
so far as to take out the little "Paddle board" and attempt any reverse
engineering. I imagine that soon others will do so and we will see Amiga
Compatible drives on the market for $150-$200.
As soon as I get a cheap hard drive less than $1000 for 20MB fast access (my
personal max) the second drive will most likely be sold to someone operating
on a budget. It is nice to know that the drives in there are standard and can
be replaced for less than the cost of a service contract on them. (if they
break throw them out or sell them to a student cheap and replace yours with a
new one) Another sad commentary on our throw away society.