Changes

VDOS was supplied on an [[EPROM]], and was released in 3 4 versions:

== RSX Commands in German and English; VDOS differences compared to AMSDOS Details ==* Some commands are available in German and English language. This is an advantage when using more than one DOS ROM at the same time.* Vortex is a German company, so they added RSX commands in German and English language. The normal AMSDOS RSX commands VDOS had both |TAPE.xx and |DRIVE/|USER were added as |CAS and |SELECT (which resemble equivalent German words word ''Kassette'' and ). (Dobbertin's X-DDOS had the same for compatibility). * |USER/|DRIVE did not exist in V1.0 instead |SELECT is used (which resemble equivalent German word ''Selektieren''). Also (Dobbertin's X-DDOS does supports both the English and German languagesalso had |SELECT for compatibility).

* VDOS supplied both German ROMs (with messages in their native language) and English ROMs where the messages are translated. The RSX commands are identical. * When using the firmware function CAS CATALOG you give it the address of a buffer to fill with the list of files in the current user and drive(in SOFT968 this is a 2KB buffer but only because AMSDOS is limited to 64 directory entries and each directory is 32 bytes - 64x32 = 2048). The For VDOS you should use a 4KB buffer to support 128 directory entries. In addition the format of this the data stored in the buffer differs compared to AMSDOS.

Therefore it's recommended to use SELECT to specify the user. A program should also not rely on the memory location of DOS specific data and poke it directly. Therefore it should use KL FIND COMMAND to detect |SELECT and use that if found, otherwise find and use |DRIVE and |USER. This allows maximum compatibility.

* VDOS will autoboot a file called "HELLO.BAS" if it exists on the disc. AMSDOS doesn't have this. This is VDOS's 'Turnkey' system. * VDOS 1.0 supports 3 drives but only two are accessibly by VDOS at one time. The DOS stores details for 2 XDPB at one time. Using |S you can change the logical drive mappings. Logical drive A is normally unit 0 and logically drive B is normally unit 1. With |S you can map unit 2 to logical drive A or to logical drive B.  |S,0 - 3rd drive is ignored:  |S,0:|SELECT,"A" - access unit 0 |S,0:|SELECT,"B" - access unit 1  |S,1 or |S,2 - choose if 'A' or 'B' is 3rd drive. i.e. Decide if |A is 1st drive or 3rd drive or |B is 2nd drive or 3rd drive.  |S,1:|SELECT,"A" - drive A is unit 2. |S,2:|SELECT,"B" - drive B is unit 2. * TO BE CONFIRMED: VDOS supports other double sided disc formats by programming the XDPB. AMSDOS doesn't allow this. * When using CAS TEST EOF firmware function and soft end of file is reached the following conditions are return: carry true, zero false, A=&1A this is different to AMSDOS which has the conditions: carry false, zero false, A=&1A * When using CAS IN OPEN/CAS OUT OPEN VDOS will crop the filename and extension part. i.e. if you use the filename "LONGFILENAME.LONGEXTENSION" it will crop it to "LONGFILE.LON" and attempt to load it. AMSDOS will give a 'Bad command' error. * VDOS has different error codes compared to AMSDOS. * You should push/pop ix and iy around firmware functions if you use them. VDOS appears to have different conditions for some CAS functions. TO BE CONFIRMED: exactly which functions are different. == VDOS for Vortex Winchester Harddisk == * The VDOS for the WD20 doesn't seem to autodetect the harddisk. It asks you if the interface is connected before accessing it. == Vortex Disc format == Sector numbers are 01h..09h (same as AMSDOS IBM Format, but with a 9th sector).Disks are Double-Sided, Double Density, 80 Tracks, 9 Sectors, blocks are allocated in 4K units.Total capacity is 720K (704K available):* First 9K contain two System Tracks (eg. CP/M Bootstrap)* Next 4K contain directory (see Note)* Next 704K are data (allocated in 4K blocks) (aka 4K clusters)* Last 3K are unused (due to 4K allocation size) Note: According to the manual, the directory can hold 128 entries under VDOS2.0 (whole 4K used), but only 64 entries under VDOS1.0 (only half of the 4K area used).

Image:VDOS-internal.JPG|Internals photo(VDOS in a Modul-X)

* [[Media:Vortex10.zip| V-DOS VDOS 1.0 ROM]] * [[Media:Vortex20.zip| VDOS 2.0 ROM]] * [[Media:VDOS20X.ROM| VDOS 2.0-X ROM]] * [[Media:VDOS_decoded_TFM.ROM | VDOS 2.11 ROM (decrypted, works as normal ROM but not in Vortex disc controllers. Hold space key after reset)]]