VSG Virtual Sector Generator

[Mike_Z]

Last week, I purchased a Virtual Sector Generator from Mike Douglas. Since I only have a dozen or so 10 sector hard sector floppy disks for my newly revived SOL-20 and no one seems to be making them, I thought I'd give this a try. The unit arrived yesterday. First thing I had to do was find a 34 pin ribbon cable. This unit plugs in between the floppy controller and the drive units. As luck would have it, I didn't have a cable like that. So, I made one from a couple of spare floppy cables I had. But to make it work, I had to grind off the header tab, because the old header plug doesn't have this index tab. AND, there were plugs in two of the socket holes. These had to be removed. Fortunately, the pin connectors are still in the header. I just drilled the plug and then pried the plug out as well as I could. Next the cables were installed, the 9 volt battery connected and the SOL-20 powered up. I had hard sectored floppies in drives A: and B: and an unformatted soft sectored floppy in C:. The SOL booted up and I could start CP/M on A:. Then I formatted the floppy in C: and copied B: to C:. Everything worked well. The entire process is transparent and I don't have to worry about turning anything on or off, or where, or what kind of floppies are used. Well worth the money.

The next project will be to install the VSG into my drive enclosure. There is a small spot in the back where the ribbon connector is. I'll devise some kind of CB holder and some connectors. Then the battery will be removed and I'll power the CB with +12 volts from the drive unit. Hopefully, all will work and there will not be anything more hanging off the back of my SOL-20. Thanks Mike for a really neat part. Mike

 

[Hugo Holden]

Hi Mike_z,

I also mounted Mike's VSG inside the disk drive housing, the pictures in the article here show how I did the mechanical mounting of the VSG board. I built two of these units (I like to have spares):

http://worldphaco.com/uploads/EXTERNAL_DUAL_5.pdf

I also made up a ribbon cable joiner, so I can unplug the unit from the Sol without taking the top off the Sol or removing the connector from the N* card.

It is great that the VSG is "transparent". It is a wonderful device, I don't know how I would have managed without it.

In my case I'm using the N* double density controller. I used old stock Japanese made IBM YD-580 drives and have has little trouble at all. Except that these particular drives detect hard sector disks and disable the pulses. But it has never been a concern for me because I have only used soft sectored DSDD disks with my SOL. I have found the 3M brand of disks, of late manufacture, to be the better type.

 

[Hugo Holden]

When Mike's VSG was used outside a housing and battery operated it provided a very convenient and safe way to separate the ribbon cable and the drive unit from the SOL. Of course if the VSG is put inside the drive housing, unless its connector was exposed in some way that function is lost. Also I think its better not to plug the cable on and off the N* card, as it can be plugged in both ways, that worried me.

I was also wondering about putting some sort of multi-way connector on the rear of the drive housing, but it would have been a little crowded. So I let the ribbon cable from the VSG simply exit the drive housing and used the joiner (photo attached) so I can separate the drive unit and the computer to easily move them around. I put it in the middle of the cable, so that keeps the dangling lengths of ribbon as short as possible from each unit when they are separated but maximizes the total length of cable too as I have the drive unit typically beside the SOL, not on top if it.

 

[Nama]

I have another solution for a quick disconnect for drive cables...I'll try to get some photos of my home made solution this evening.

Philip

 

[Mike_Z]

Hugo, my Omega triple disk has a 34 pin connector on the back of the case. The VSG was placed between the disk ribbon cable and this external connector. From an external view point the system is exactly the same. And even a guy with a slow leak, like me can connect things just fine. Mike

 

[Nama]

Here is my solution for a floppy quick connect/disconnect