Ultimate FDC? (Was: IBM 6360 - Filesystem(ish) info?

Fred Cisin cisin at xenosoft.com
Tue Feb 19 21:01:07 CST 2019

On Tue, 19 Feb 2019, Ali wrote:
> That would make for a very powerful tool but as you pointed out yourself 
> how many users would learn to use it? Unless it is a simple driver that 
> gets loaded and the user has to simply put in a couple of generic 
> parameters, e.g. "device=c:\drives\emudsk.sys APPLE", and it is up and 
> running most users won't be able to make use of it.

By the time that I got out (for other reasons), XenoCopy had not been 
profitable for a while.  THAT handled files, but the user still had to 
deal in other ways with modifications that they needed to the content of 
the files.  Sure, a Wordstar file could be made into a generic text file 
by stripping the high bit.  But converting WordPervert format codes into 
Weird format codes would have required another career.

> > My preference would be REAL MODE (DOS).
> As would mine but would a 286 be able to do it? And if you have a 
> machine that runs real mode DOS why not make use of the HW that is 
> there?
For your 286 machine(s) wouldn't you like a combination of Compaticard, 
CatFerret, and option board, to use instead of the existing FDC board?

If this were USB, then it could add floppy back onto some more "modern" 
machines.  If USB, with appropriate "modern" drivers, no reason why this 
couldn't be used for MOST machines.

> > Match Point could be implemented in software on the Central Point 
> > board.
> Great. Then if the DOB HW is duplicated then that part can be SW 
> and no need to have Match Point HW duplicated. I am surprised the Copy 
> II PC DOB card did not handle Apple II disks along with Mac 
> disks.
It could have.  But Brown? (not sure whether I remember his name right) 
correctly realized that he could make money doing Mac, but there wasn't 
enough additional money with Apple2 to even necessarily reimburse him to 
hire those programmers.

> > CompatiCard was just an ordinary FDC, without the crippling corners 
> > cut.
> True, but if you are building the ultimate FDC then you don't want 
> crippling corners cut. So something functionally equivalent.
Exactly.  But, I want to make it clear that there is nothing SPECIAL about 
Compaticard; it's simply one of the best, but not unique.

> > SO, you are asking for FDC plus flux transition, but better 
> > integrated, rather than flux transition hardware interrupting the 
> > drive cable.

By the time DOB came out, 286 normally had FDC combined with HDD, so my 
suggestion to integrate FDC with OB wasn't applicable.

> Yes! All on one card. Throw in FDADAP functionality to properly write 8" 
> disks and you have a controller that handles most if not all IBM, Apple 
> II, and Mac disks.
FDADAP is a cabling adapter, plus generating the TG43 signal, which would 
be trivial to do with a conventional FDC.  For READING (I hardly never 
WROTE), I cabled my 8 inch drives to 34 pin.

> As I understand it, in my limited way, having both FM 
> and MFM should allow for many CP/M formats including SD.

Yes.  FM adds 8" SSSD "Standard", TRS80 model 1 (although still problems 
writing some address marks), and a handful of others.

> Will some formats be left out? Sure.

GCR, hard sector, etc.
My (and I think Chuck's) favorite example for weird is Sirius/Victor 9000.
(80 track GCR, although with its own versions of CP/M-86 and MS-DOS!)

> Will it be as powerful as a Kyro 
> Flux for archiving? Heck no.

But will it let me pop in my original 123 
> disk and copy it for use with out too much hassle and work? Of

> course.Â

> There are a few exceptions, such as Pro-lock.Well then you had
> the ENHANCED Deluxe Board. :)
Not necessarily.  MANY versions of Pro-lock used the same identical check 
code, so one "crack" beat a lot of them.  But some of the better ones 
rewrote their own subroutine.

Pro-Lock relied on a physical defect on the disk.  Both in terms of 
getting an read error trying to read that track, but sometimes even 
confirming that WRITING to that track also failed.
They called it a "laser fingerprint", because "a sweatshop where they 
scratch disks with a paperclip" doesn't sound as impressive.
Similarly, my Prius has a "LASER CUT key".  Yeah. Right.  The one that I'm 
using right now was cut with a tiny side-mill bit and a pantograph.

> > But, in quite a few cases, people have disassembled (now illegal under 
> > >DMCA!), found the vulnerabilities and
> >simply disabled the copy protection.Â

> Yes but that is harder and harder to find. They were never public but 
> each city had multiple BBSes offering such altered programs. And of 
> course the other problems w/ this method is you are confined to the one 
> altered version  (even if you own a later version). Also there is no 
> guarantee the alterations will not cause a bug that will crop up later 
> due to a lack of total testing.

I removed the copy-protection from my [legitimate] copy of 123.  So that I 
could install it onto machines with different drives.
Sorry, I don't remember where the patch is.

But, is it really that hard to find the patches for the major programs?
I don't doubt your statement; I'm just surprised.

In the mid 1980s, when I had a publisher, they copy protected Xeno-Copy!
It used to be, that if I Googled XenoCopy, many of the hits were for a 
patch to remove the copy protection from those early versions.  Still are!
I set up my publication of XenoCopy to be unprotected once it was 
"installed" (putting user name on title page.  Prior to the name going on, 
I used a ridiculously simple protection to protect from copying of 
unpersonalized copies (just using an inconvenient "feature" of MS-DOS)
Even XenoCopy would freely copy those disks!  But DISKCOPY wouldn't.

Although I never had reason to EVER use it, I designed a trivial copy 
protection that was copyable to a usable copy with DISKCOPY, but the 
original disk could not be read by the Option Board (It relied too much on 
index pulse).  Once Option Board was stopped, it could have had something 
else added to make it inconvenient to copy.

Grumpy Ol' Fred     		cisin at xenosoft.com

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