Double 3.5 disk drive issue.

[chriskgnr]

Here are the things until now:
With a straight through floppy cable and one disk drive plugged, the disk drive responds at flp2_ commands. In other words it is jumpered as DS1. The same thing happens when i plug the second drive. So, i have two DS1 (flp2_) floppy disk drives. With the same straight through floppy cable and one disk drive plugged i can format a DD disk(720K), save a program, load or delete a program etc. But what it happens is that whenever i do a format, copy, save, load, run, lrun command, i must before that, reset the QL just to execute succesfull the command! Let's say that i boot the QL and i format a disk with command "format flp2_" or just do a "dir flp2_" to see the directory listing. From now on any command like dir flp2_, save flp2_, format flp2_ etc returns the "not found" error. The same thing happens when i plug the other drive. It is like that i can execute succesfull just one floppy disk drive command and then i must reset the QL. Flp_ command-reset, flp_ command-reset, flp_ command-reset. Like the disk drives need something of initialising... What i think is that CST Qdisc floppy disk controller, works correct ONLY with that old original Shugart disk drives...

[chriskgnr]

Three months ago i desoldered all the ic's, soldered ic sockets, cleaned the pcb, changed the 7805 regulator with another with bigger amperage, made recap( i think it is just one electrolytic capacitor), cleaned the oxides(did my best) from the ic's pins. As i stated before the same disk controller works flawless with a Cumana 5.25 double disk drive set!

[RWAP]

Very odd - although I admit that I had problems in the past with CST QDisc interfaces and getting them to work.

I would definitely try changing the disk controller for a WD-1772 - it is pin compatible, and should work (though no guarantees).

I wonder if it is a timing issue because the CST was created when floppy disk drives had an access time of 15ms (or more) so the disk drives might be too quick once running - is there a FLP_STEP / FLP_OPT / FLP_START command on the CST (I forget) - do an FLP_EXT: EXTRAS command to see what there is...

[chriskgnr]

there is only FLP_USE command.

[prime]

I wonder if the CST interface requires the /ready signal to be available on pin 34 of the drive? The 5.25" drives may well be jumpered to generate this.

However the 3.5" drives (which I am assuming are actually 1.44MB PC type floppies as they are both set to DS1) will have the disk change signal on pin 34, it may be that after the first disk access this signal is changing state and when the CST interface reads it, it interprets it as drive not ready.

I've seen a similar problem to this with BBC micro disk interfaces, I know the Spectrum +3, and Amstrad CPC disk systems do nead pin 34 to be /ready, so a drive that works with them may solve the problem (if this is the problem).

Cheers.

Phill.

[RWAP]

Just another thought - some years ago I had problems with a disk interface and dual disk drive I sold to a customer - he returned them to me as was struggling to get them to work - I can't remember the exact details, but they worked perfectly for me, so he sent me his QL, and it all still worked perfectly.

In the end it transpired the problem was that the QL and disk drive were plugged into an extension socket in his house (a 4 way strip) - when he plugged it direct into the mains it worked fine...

[chriskgnr]

I made the pin 34 (ready signal) modification. Nothing changed. The set is already trashed.
Thanks everybody for the help!

[lliont]

Hi
I had a similar problem.
Connecting line 34 to gnd (line 33) on the controller side worked for me and finally I can use my Micro P. disk system.
I had already crossed line 10 with line 12 because I use a PC floppy drive.
I use 1.44 HD floppy with 720K DD disks (1.44 disks with the hd hole covered actually).
thank you very much Phill.
Leon

[chriskgnr]

Hi
I had a similar problem.
Connecting line 34 to gnd (line 33) on the controller side worked for me and finally I can use my Micro P. disk system.
I had already crossed line 10 with line 12 because I use a PC floppy drive.
I use 1.44 HD floppy with 720K DD disks (1.44 disks with the hd hole covered actually).
thank you very much Phill.
Leon

Unfortunately, it didn't work...

[stevepoole]

More on floppies :
I have an sgc_QL under SMSQ/E and a QPC2_PC. I formatted a floppy and copied a program onto it on the QL. Dir lrun etc work fine. Back on QPC dir flp1_ shows an empty disk!
So I copied another program onto the same floppy using QPC. Dir lrun etc work fine for that program.
back on the QL, dir flp1_ only shows the first copied program... no QPC'd copy!
So The floppy seems to have two seperate partitions, one for each computer.
By the way, this could be a copy protection mecanism, as I had copied my (purchased) Turbo and Lightning microdrive tapes, so as to transfer them to my old PC, for transfer to my new PC which has no floppy device, just USB... The floppy was a reformatted one I have used before successfully!
What is going on?
Steve.