Re: Apple floppy adaptor. I'm stuck!

[Tristan Mumford <xtristan.xmumford@xgmail.xcom>]

NOOOOOOOOOOO!!!! My uC bricked on me!!! It's been unreliably writing for a
while now. Since it was in other projects even. The programmer even
complains that RTS is high. It worked last time it was in the adaptor too.
It doesn't work there anymore.

I plugged it back into the adaptor just to confirm. What I saw made me want
to cry. First time around I forgot to put a floppy in the 3.5" drive. Apart
from the head not moving (which I expected) something unexpected happened.
I plopped my test floppy in and after a couple of seconds the normal boot
display disappeared and was replaced by a cheery "16 SECTOR" in the middle
of the screen, where it just sat merrily.

I decided to reboot and try that again. This time with disk in. It popped up
with "13 SECTOR". Not surprised because of the crummy hex inverter. It's
probably dropping signals all over the place.

Third time's a charm. Did it with disk in again. "16 SECTOR".

Such a shame because I believe I fixed the head stepping error in the
firmware. That's why I pulled it.

Anyway, my reply is below \/\/\/\/\/\/ :)




Payton Byrd wrote:

> 
> 
> "Tristan Mumford" <xtristan.xmumford@xgmail.xcom> wrote in message
> news:45d65274$0$52912$c30e37c6@lon-reader.news.telstra.net...
>> Michael J. Mahon wrote:
>> 
>>> 
>>>> I'm hoping I can get this issue sorted, because it's nearly done! I
>>>> hope I can get it working right, because I actually decided to use a
>>>> calculator to figure out final storage capacity *Gasp!*. A 2HD disk
>>>> should hold 640kb. In it's current form a normal 2HD disk appears as
>>>> one big single-sided 160 track disk.
>>> 
>>> Several places in the Disk ][ driver/RWTS think that a disk has at most
>>> 40 or so tracks--like recalibration.
>> 
>> D'oh! I wonder what I can do about that. Because I have ultimate control
>> of the head I guess I could make a single floppy into 4 x semi-virtual 40
>> track drives. The uC keeps track of the trackcount, direction, and side
>> of disk so it shouldn't be too hard at all.
> 
> Do like PC hard drives and lie to the computer about sectors per track.  I
> don't know how many sectors you are placing on a track, but if it's 16,
> then tell it there's 64 and then have 4 physical tracks of 16 = 1 logical
> track 64.

With some patching I guess it would be possible. The idea of my project was
a software and hardware patching free, inexpensive way to use the
disturbingly abundant 3.5" floppy disks on an apple2. At the current point
in time if one were to go for the frivolously expensive means of buying a
small prototype board, connectors, wire, the uC, hex invertor, and
capacitor from DSE it would still come in under $AU20. As it is I'll be
forced to get a replacement 16f628a from there @ nearly $11. Except that
may have to wait somewhere between a week to 2 months depending on
finances. Trips to Melbourne every couple of weeks on top of normal
outgoings have nuked me for now. I don't suppose anyone has a spare 628a,
or any other 18 pin PIC with internal RC oscillator lying around???? It's
so painfully close to working it hurts!