3.5" floppy drive in a Model IV
jon
80 model IV? The jumpers can be set properly, but I'm at a loss as to
how to install it (replacing drive 0). I figure I'd need to somehow
adapt the different floppy cords (one is for a card edge, the other
IDE) but how about the power supply? Has anyone done this and can you
help? Sorry if this is a redundant/ignorant question.
Knut
Some pictures of how I did it on my model III and 4
http://home.online.no/~kr-lund/m3.htm
http://home.online.no/~kr-lund/m4.htm
There are adapters for use with (older) pc's for the cables if you don't just
make new cables. One trick for me was to add the extra internal drive the 5.25"
:2 drive gets its signal from the underneath of the floppy-interface-card
connector and is jumpered for :0 similar to an external drive.
The drive is seen to any DOS like whatever is the maximum, so for LDOS like a
5.25" DS 80 track and DD if you have a DD kit. Using it for SD, single sided and
35 track is no problem it is just a parameter when you format it.
Media should be 720K i.e. DD because 1.44 MB (HD) is not possible with standard
TRS-80 model I/III/4 hardware. In my experience 1.44MB media can be used but
with the extra hole covered by tape so the drive thinks it is 720K DD (no bad
tracks or failing data even years later).
If you use a DOS which can adjust the timing the typical 3.5" need only the
minimum settings making access very fast.
It seems to me that 3.5" drives are much more reliable than 5.25".
Knut
jon
> jon wrote:
> > Anyone know how to install a (Panasonic) 3.5" floppy drive into a TRS
> > 80 model IV? The jumpers can be set properly, but I'm at a loss as to
> > how to install it (replacing drive 0). I figure I'd need to somehow
> > adapt the different floppy cords (one is for a card edge, the other
> > IDE) but how about the power supply? Has anyone done this and can you
> > help? Sorry if this is a redundant/ignorant question.
>
>
> There are adapters for use with (older) pc's for the cables if you don't just
> make new cables. One trick for me was to add the extra internal drive the 5.25"
> :2 drive gets its signal from the underneath of the floppy-interface-card
> connector and is jumpered for :0 similar to an external drive.
>
> The drive is seen to any DOS like whatever is the maximum, so for LDOS like a
> 5.25" DS 80 track and DD if you have a DD kit. Using it for SD, single sided and
> 35 track is no problem it is just a parameter when you format it.
>
> Media should be 720K i.e. DD because 1.44 MB (HD) is not possible with standard
> TRS-80 model I/III/4 hardware. In my experience 1.44MB media can be used but
> with the extra hole covered by tape so the drive thinks it is 720K DD (no bad
> tracks or failing data even years later).
>
> If you use a DOS which can adjust the timing the typical 3.5" need only the
> minimum settings making access very fast.
>
> It seems to me that 3.5" drives are much more reliable than 5.25".
>
> Knut
OK so in order to make a new cable I'm just going to crimp a 5.25"
connector to the end of the IDE cable. When I do this, should I
"untwist" that funny twist next to the connector when I install it?
Is is simple enough to fashion a power supply cable?
jon
> On Nov 9, 4:21 pm, Knut <kr-l...@nogarbage.online.no> wrote:
>
>
>
> > jon wrote:
> > > Anyone know how to install a (Panasonic) 3.5" floppy drive into a TRS
> > > 80 model IV? The jumpers can be set properly, but I'm at a loss as to
> > > how to install it (replacing drive 0). I figure I'd need to somehow
> > > adapt the different floppy cords (one is for a card edge, the other
> > > IDE) but how about the power supply? Has anyone done this and can you
> > > help? Sorry if this is a redundant/ignorant question.
>
>
> > There are adapters for use with (older) pc's for the cables if you don't just
> > make new cables. One trick for me was to add the extra internal drive the 5.25"
> > :2 drive gets its signal from the underneath of the floppy-interface-card
> > connector and is jumpered for :0 similar to an external drive.
>
> > The drive is seen to any DOS like whatever is the maximum, so for LDOS like a
> > 5.25" DS 80 track and DD if you have a DD kit. Using it for SD, single sided and
> > 35 track is no problem it is just a parameter when you format it.
>
> > Media should be 720K i.e. DD because 1.44 MB (HD) is not possible with standard
> > TRS-80 model I/III/4 hardware. In my experience 1.44MB media can be used but
> > with the extra hole covered by tape so the drive thinks it is 720K DD (no bad
> > tracks or failing data even years later).
>
> > If you use a DOS which can adjust the timing the typical 3.5" need only the
> > minimum settings making access very fast.
>
> > It seems to me that 3.5" drives are much more reliable than 5.25".
>
> > Knut
>
OK so in order to make a new cable I'm just going to crimp a 5.25"
connector to the end of the IDE cable. When I do this, should I
"untwist" that funny twist next to the connector when I install it?
Is is simple enough to fashion a power supply cable?
5.25" floppy unit? There's the power on the bottom, the cardedge
connector, and four extraanneous ones. What are they for?
Knut
The twist on the floppy cable is an IBM PC and compatibles specific trick and is
used on no other platform as far as I know. So no, not TRS-80 model I/III/4
either. :-)
Power is separate and you could use an adapter for 3.5". But it is of course
amazing what one can do with a soldering iron there... ;-) I would of course
make it so that any soldering is done on the 3.5" drive so the original cable
stays original.
Extraonous? Where? There are 3 times 4 pins on the powersupply all of them are
the same. One goes to the floppy interface card, one to the upper drive and one
to the bottom drive if that is what you mean. On the drives there should only be
the edgeconnector (or the interface plug on the 3.5") and then there is the
power socket. A grounding cable might be using the screw for the lower drive to
ground the metal of the "floppy tower".
Knut
jon
No sorry I must have been dreaming. Those I referred to are just
plugged in within the unit. My bad.
I've got everything now. Found a cable in our school's "junk" room.
Thanks so much for your help. Love your site, and that Play CAS
programme!