[Offer] Flushot plus 1.7a (SCP, IMZ) [5.25]

callmejack

This is version 1.7a of Flushot plus antivirus

This is an early antivirus for IBM PC and compatible, dated 1989.

https://mega.nz/file/CHwTDQoA#D68P5EUb_8tUo3YUUi7ns2xvksRBcU2ZP297dP06JZM

ibmpc5150

Thanks!
I also have same disk of it, now it is verified that is same SHA1 of disk image.

callmejack

just for curiosity, on what image format do you check the SHA1 ? It cannot be the SCP as it varies too much from one floppy to another.

ibmpc5150

@callmejack

Your uploaded .imz is just ZIP archive. I renamed .imz as .zip and extracted the dumped image file from zip file.
Also I converted .scp file to .psi first.
Then I've checked attribution of psi, and converted to .ima file.

I always check the following by using SHA1 tool and FC command on Command prompt.

callmejack

So if I understand correctly, you convert SCP -> PSI -> IMA and compare SHA1 from this IMA to the one from the IMA extracted from the IMZ file ?

How do you convert from SCP to psi ? I don't seem to find this format in HxC floppy emulator. I also tried psi.exe but it failed loading scp file.

SomeGuy

PSI is an intermediate format used by the PCE emulator. PSI can hold odd sector geometry that is not possible in an unstructured sector image (IMA/IMG) Converting is the same as converting a kryoflux image. For example:

pfi "Flu-Shot plus 1.7a.scp" disk1.pfi
pfi disk1.pfi -R 1 -r 500000 -p decode pri disk1.pri
pri disk1.pri -p decode mfm disk1.psi -f -v
psi disk1.psi disk1.img
psi disk1.psi -L > disk1.txt

ibmpc5150

@callmejack

This is a Basic usage example what SomeGuy show you.
I use it in a variety of ways with more advanced options.

callmejack

Thanks, that's very interesting. Can PSI format handle some copy protection based on abnormal sectors and then one can create and IMG file that could be used on an emulator to run the copy protected software?

ibmpc5150

@callmejack

I know PSI format handle on PCE emulator only.

PCE emulator supports various disk copy protected track/sector (Non standard sector)

SomeGuy

IMA/IMG files store no geometry structure and only contain the contents of known standard formats. As disk based copy protection involves non-standard formatting, by definition, IMG can not contain copy protection.

The entire point of PSI is that is can contain most, although not quite all, IBM PC style copy protections. PSI, however, is specific to the PCE emulator. Many copy protected titles can be converted to PSI and then run inside PCE.

callmejack

Thanks very much, I always love to learn new things in this forum😊

callmejack

The commands above to convert SCP to IMG don't seem to work with HD floppies images (1.2MB and 1.44MB). Is there another parameters for those format ?

SomeGuy

The key there is that you have to specify a different data rate:

For 1.2mb or 1.4mb disks:

pfi track00.0.raw disk1.pfi
pfi disk1.pfi -R 1 -r 1000000 -p decode pri disk1.pri
pri disk1.pri -p decode mfm disk1.psi -f -v
psi disk1.psi disk1.img
psi disk1.psi -L > disk1.txt

Note that 1.2mb and 1.4mb disks spin at different speeds, but the high density data rate is the same. That is why 1.2mb disks don't fit quite as much data. Some tools need to know about rotation rate, but not this one.

360k disks in a 1.2mb drive are another story, as the same disk spins faster in a 1.2mb drive than a 360k drive, so the data rate is a bit higher. For those:

pfi track00.0.raw disk1.pfi
pfi disk1.pfi -p double-step -R 1 -r 600000 -p decode pri disk1.pri
pri disk1.pri -p decode mfm disk1.psi -f -v
psi disk1.psi disk1.img
psi disk1.psi -L > disk1.txt

We also add the double step parameter to avoid decoding garbage on unused odd numbered tracks.

BTW, if decoding FM instead of MFM, the data rate must be half of what is specified above. But IBM PC disks don't use FM.

callmejack

Thanks very much for this useful and comprehensive explanation. Another day learning something new

SomeGuy

I've also added another copy with box and manual scans here:
https://winworldpc.com/product/flu-shot-plus/

ibmpc5150

Most of them work without problems when converted to PSI format in the basic way.
However, the relatively old and copy-protected disks do not work properly with basic conversion, but there are some cases where they do not work.