Corcomp disk controller questions and Ex Bas 2.7 Suite compatibility

[aftyde]

Hi All,

 

Just scored a Corcomp DS/DD controller on eBay for a too high price. However, having some minor issues.

 

Because the Corcomp throws up it's own boot screen - it intercepts the Ex Bas 2.7 suite menu. When I select the cart on the Corcomp menu the system hangs. (though I must assume it works for someone as the Corcomp diagnostics are on the cart)

 

I can't get to boot manager (download a disk image) because ftp at WHT seems to be having permissions problems and I can't go any deeper than 1 subdir - so if anyone could pitch me a disk image of the latest Corcomp utilities that would be awesome.

 

So basic questions - anyone using it, do you have the utils, are you using a Lothrek (and if so, can you send diskette image specs for the 40 and 80 track disks that I can try out. Trying to get a working 2880 sector disk happening. (I do have it working on my Myarc in the other PEB - but not so far on the Corcomp) Is there some way of bypassing or turning off the boot screen? I looked in the manuals but didn't see anything obvious.

 

The controller seems to be working - both Lothrek drives are responding and my 40 track images seem to be working. Is there something specific I need to do on the controller (cracking the case) to make it work?

 

Apologies for so many questions - it seems that every new disk controller is an adventure!

 

Cheers, Arthur...

[+RXB]

The Myarc Floppy Controller modified to do 80 Track works great as I have one. But the Corcomp never had 80 Track as the chip is the wrong one for the Corcomp to do this.

 

As for the Main Menu on the Corcomp you may have a older unmodified version so you need the upgraded Corcomp EPROM.

[sparkdrummer]

You will need to get the Miller graphics eprom set to eliminate the corcomp screen. These are available from arcadeshopper.

[mizapf]

The Myarc Floppy Controller modified to do 80 Track works great as I have one. But the Corcomp never had 80 Track as the chip is the wrong one for the Corcomp to do this.

 

The CC uses a WD2793A, which by its specifications can handle up to 76 tracks. I just compared it to the other FD1771 and WD177x chips, and they all mention track 76, so I wonder why the 80-track upgrade for the TI controller actually works. Obviously the controller does not check the upper bound; the track register may go up to 255. So it is a bit surprising why the WD2793A cannot do what its predecessors were able to.

 

Maybe there was just no one to write a new DSR?

[+Ksarul]

The only way you will ever see a CorComp working with 80-track disks is when using it with the Master DSR of the Geneve9640. That DSR will make 80-track mode available to any of the DSDD controller cards. As Rich already noted though, there is no stand-alone 80-track DSR for it, so without a Geneve, you are out of luck unless you write your own modified DSR.

 

The CorComp Menu has issues with a lot of software, not just the XB2.7 cartridge. Your best bet there is to replace the DSR chips with the MG EPROMs, as they are comparible with everything out there, software-wise.

[+Ksarul]

The 77-track reference is for those situations where the controller chip is working with 8" disks. . .

[RickyDean]

Yes I can verify that when using a Geneve, I can access 80 track drives with a Corcomp.

[aftyde]

Thanks for the info - bummer, I was really hoping it would do the trick. In any event - I'll upgrade the thing with the MG eprom set. The card is in pristine condition - so it seems a shame to not maintain it.

Very much appreciate the response!

Edited September 26, 2016 by aftyde

[justacruzr2]

A cheaper alternative than the MG eproms is to simply press the space bar twice. This will land you at the TI menu. This was a known workaround for the software that would not work correctly from the CorComp menu. Try this first before you spend money. I can not be sure that this method works for everything but it does work for everything I have.

[aftyde]

Yep - I eventually figured out that I could access the menu by going to the color bars, then the module menu. It's pretty wonky... will probably get the ROMS because I support what Gregory is doing! And I figure - why not??? LOL

Here is a picture of the card - anyone know what the jumpers near the eprom do?

 

[Omega-TI]

 

Here is a picture of the card - anyone know what the jumpers near the eprom do?

 

 

I don't remember since I've not had one in over 20 years, but the attached (poor quality) PDF may have that information...

CorComp Floppy Controller.pdf

[atrax27407]

Maybe # of drives?

[etownandy]

Didn't this controller have adjustable head step timings?

[mizapf]

Page 5, step times (two dip switches per drive DSK1-DSK4)