Opus Discovery

[Maryjan]

Please use my firmware for 27c256 (or 27c257). See attachment under the post)
There are four firmware for Opus Discovery. From the oldest (only for the ZX 48k) to the newest (1.2;2.2;2.22 and 2.31).
We select the firmware with the JP1 and JP2 jumpers.


The AB / BA pins on Opus are (looking at them from above):

1  2
3  4

1 of 2 and 3 of 4 - AB, 1 of 3 and 2 of 4 - BA.

[dicesare]

Some improvement.
I burned Maryjan's ROM and set QuickDos as default (by the way you can check the active ROM version with PRINT USR 8 ).
I set the AB / BA jumper with a vertical jumper next to the MC6821
Now at every boot the drive is stopped and if I send a disk command, the drive starts spinning and its LED lights up.
I can't hear the head move at all.
I also try using a second WD1770 as spare and it doesn't change anything.
What could it be now?

[Maryjan]

Is the jumper on DS0 set in the drive?

[dicesare]

Yes, the drive spin up for a while, then I have a "e Write protected 0:1" error

Thanks

Claudio

[Maryjan]

Are you trying to format a floppy disk and it displays this message ?
It looks like the floppy disk is write-protected.
Can you insert a picture of the connected drive ?

[damik]

In this case, do you have an HD or DD floppy disk in drive?

[dicesare]

Hello friends,
firts, thank a lot for the help you are giving me!

@Maryjan
I'm trying to see the content of floppy, I give a CAT 1 command.
I enclosed a photo of drive, is a ALPS generic 1.44 PC type configured like DS0.
I tryed also a Mitshubishi MF353C a 720K (I used for the original Opus Discovery)
Same results for all...

@Damik
I'm using my original 180K Opus floppy, they are all DD type

Claudio

[dicesare]

I enclosed also a photo of my board setting, lease check to see if something is wrong.
Thanks

Claudio

[damik]

Try to format and read a blank DD floppy first, maybe your old disk is damaged.

[dicesare]

I try to format a blank DD disk.
For the first time I can hear the head start moving :-)
Whith ALPS drive I have a format error (error G)
So I change the drive for the Mitsubishi 720k and I successfully format the disk.
Then I try to read with a CAT 1 but again...
(see the photo) :-(

Claudio

[damik]

I have a lot of damaged floppy disks after many years.
After use, the head in the drive becomes dirty.
Try to find good working DD floppy tested on PC before and clean the heads in the Opus drive.

Format it in Opus again.

[trojacek]

Whith ALPS drive I have a format error (error G)
So I change the drive for the Mitsubishi 720k and I successfully format the disk.

Are you aware that you need to use a drive which supports equivalent of the PC 720K format?
That means 1.4M drives need modding in most cases.
I have successfully modded some Sony and Samsung drives in the past - I wanted them to work with Timex FDD3000 system.
I have never succeeded with an Alps drive, though.
Some modern (well... is it legit to call them "modern"?...) drives won't work in 720K mode at all, as they don't support this format any more.
The best option, IMHO, is to go through Amiga forums as people there know much about modding PC drives

[Maryjan]

What frequency is on pin 18 of the WD1770 chip? Maybe the generator on 74ls04 is not working.

[dicesare]

@trojacek
I know this problem, I remember when for my original Opus I was searching for a second drive. It was on 1989 after some time I was able to find the Mitsubishi MF353 that was a 720k so I bought twice. These are the one I use today and the same that successfully format the disk.
Strangely I can't read the formatted disk.
About modifying a pc floppy, you mean only the DS0/DS1 setting, because the "disk ready" / "disk read" signals are standard for the Opus implementation.

@Maryjan
Tomorrow I'll connect the scope to pin 18 of WD1770 to see waveform and investigate about clock signal.

Thank for all, I'm sure that with your cooperation we will solve this trouble ;-)

Claudio

[dicesare]

Dear friends, it finally works!
Today I was going to test the system clock to report to Maryjan and before doing this I took the WD1770 out of the socket to see how to connect to pin 18. After doing this I tried to read the directory of a floppy of my old Opus and ... Now it works!!!

So it could have been some bad contacts, however I was unable to go beyond reading the directory.
Then I remembered that almost all of my floppies were formatted and written to the original Opus SD drive. I used the 720K drive (DD) and this was the mistake.
So I decided to clean the heads of the old floppy and give it a chance too.
And it did not disappoint me, after almost 30 years it reads almost all the floppies of the time.

I enclosed some screenshots of few software I wrote 30 years ago!

Now I want to recover the files, I have to connect a modified Gotek to use Flashfloppy in addition to the original drive.
So I believe it is possible to transfer images from a physical disk to a Gotek .OPD image.
Do you have any indications for this operation? Gotek should be set as DS1 right?
If you are interested, I will keep you informed about this operation.

Meanwhile, many thanks again for your help and congratulations to Maryjan for making a beautiful piece of hardware!
Cheers

Claudio