In article <4C14EDDB.7799.131A099 at cclist.sydex.com>, "Chuck Guzis" <cclist at sydex.com> writes: I can't see how that could possibly work when you're operating in real mode and you JSR to a specific ROM address. -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/> Legalize Adulthood! <http://legalizeadulthood.wordpress.com>

On 13 Jun 2010 at 16:43, Richard wrote: The bulk of PC programs use software interrupt (e.g. INT 13H for disk access, INT 10H for video, etc.) and generally speaking do not issue FAR CALLs to BIOS routines. --Chuck

--- On Sun, 6/13/10, Richard <legalize at xmission.com> wrote: Relatively few pseudo compatibles offered both Bios and dos compatiblity. Come to think of it the only one that comes to mind is the Tandy 2000. Probably the Mindset also. Ironic since there's so much banter on the net stating an 80186 based PC was inherently incompatible in many ways. Both used the chip, although the M* was way more compatible then the T2K (which ran precious little pc s/w).

On 15 Jun 2010 at 16:29, Chris M wrote: Just curious, how would you do this, since the schemes could be quite varied? Another variation was to encrypt the code as it was stored on the floppy and decrypt in memory before execution, based on the results of the copy-protection check. Many games were boot-up games, meaning that they didn't use DOS; they simply booted up into a game. An example of this creativity is demonstrated by early versions of Harvard Graphics, which stored the letters "HGC" in the inter-sector gap on one track and used the "Read Track" NEC 765 command to check for it. That was pretty clever, as it not only used an unconventional way of getting to the gap bytes, but also depended on the disk being produced on a whole-track-write system to preserve the synchronization over the sector write splice. I seem to recall that when IBM first demonstrated the PS/2, no 3.5" copies of Lotus 1-2-3 were available, so the marketing people resorted to one of the copy-protection defeating packages to run their demo. --Chuck

--- On Wed, 6/16/10, Liam Proven <lproven at gmail.com> wrote: Highly While working in an EMI lab in the late 80s, I was told by a guy that the crackers provided the copy protection schemes (for machines like the C64), and *waited* to release these tools to the public. Don't ask me, this is what I was told. And in fact down at the calibration lab there was a file cabinet fool of the tools needed to make copies of otherwise copy protected stuff (mostly games). They had loads and loads of Commie s/w. Stuff probably garnered from bbs' and whatnot. Even some crazy stuff from abroad (no not *a* broad LOL LOL). Stuff I know I wouldn't and didn't see anywhere else.

can you send me pictures? many of the machines in that category were mostly *not* compatible. That's what makes them interesting. At least I think so... --- On Sun, 6/13/10, Richard <legalize at xmission.com> wrote: I have an