Replacing the drive with a disk emulator
ZXNet echo conference «hardware.zx»
Hello, lvd
lvd> 1. R/O
Really? Well, maybe... But it’s quite possible to do it so that at the end
operation, information from RAM (modified disk image) was written back to
flash drive.
Hello, CityAceE
Cit> But it is quite possible to do so that after finishing the work
Cit> information from RAM (modified disk image) was written back to
Cit> flash drive.
You can, but you just have to do it. ;)
Hello Shiru
Shi> I don’t know of any ready-made solutions.
http://www.amiga.org.ru/forum/viewtopic.php?t=1298
Hello, CityAceE
What's the use of a floppy drive emulator that:
1. R/O
2. Does it take tens of seconds to load each image?
You can play gams, but it’s useless for work.
Hello, acidrain
You can do TRD emulation, you just need information about the TRD format, and about
tell us about the VG93 track format: v2_wink2:
Hello, tnt23
Comprehensive information about the TR-DOS floppy disk format at a low level is contained in
this [http://trd.speccy.cz/book/TRDOSUA.ZIP] book.
TRD is a simple sequence of read sectors without
any headers and checksums, both sectors and the disk itself:
Side 0, track 0, sectors 0...15
Side 1, track 0, sectors 0...15
Side 0, track 1, sectors 0...15
Side 1, track 1, sectors 0...15
Side 0, track 78, sectors 0...15
Side 1, track 78, sectors 0...15
Side 0, track 79, sectors 0...15
Side 1, track 79, sectors 0...15
Hello, tnt23
tnt> Sector size - 512 bytes?
256!
256 bytes per sector * 16 sectors per track * 80 tracks * 2 sides = 655360
byte is the size of a standard TRD.
However, smaller and larger TRDs are rare. Smaller size - s
tail, the space unused by files is trimmed. Larger size - due to
the number of cylinders (tracks) is more than 80.
There is also the SLC format - which is essentially a stripped-down TRD with
added file header and checksum. It makes it very easy on the fly
get TRD, which is what many emulators do.
In addition, there are FDI, UDI and TD0 formats. This is for discs with non-standard
(although they are suitable for the standard one too) format. For example, standard
disks with the IS-DOS operating system can only be stored in this format and TRD
not suitable for them.
It would also be nice to support these formats...
Hello, CityAceE
Cit> Comprehensive information about the TR-DOS floppy disk format at a low level
Cit> is contained in this [http://trd.speccy.cz/book/TRDOSUA.ZIP] book.
Cit>
Thanks, I'll take a look.
Cit> TRD is a simple sequence of read
Cit> sectors without any headers and checksums, like sectors
Cit> and the disk itself:
Cit>
Cit> Side 0, track 0, sectors 0...15
Cit> Side 1, track 0, sectors 0...15
Cit> Side 0, track 1, sectors 0...15
Cit> Side 1, track 1, sectors 0...15
Cit> ...
Cit> Side 0, track 78, sectors 0...15
Cit> Side 1, track 78, sectors 0...15
Cit> Side 0, track 79, sectors 0...15
Cit> Side 1, track 79, sectors 0...15
Sector size - 512 bytes?
Hello, CityAceE
Cit> In addition, there are FDI, UDI and TD0 formats. This is for drives with
Cit> non-standard (although they are suitable for the standard one too) format.
Cit> For example, standard disks with the IS-DOS operating system can be
Cit> can only be stored in this format and TRD is not suitable for them.
Cit>
Cit> It would also be nice to support these formats...
No need to waste time, let's start small :smile:
Hello, tnt23
Someone throw at me an example of a TR-DOS track, with visible to the naked eye
with the eye all sorts of marks?
Hello, CityAceE
Cit> In addition, there are FDI, UDI and TD0 formats. This is for drives with
Cit> non-standard (although they are suitable for the standard one too) format.
Cit> For example, standard disks with the IS-DOS operating system can be
Cit> can only be stored in this format and TRD is not suitable for them.
Cit>
Why can't IS-DOS live on a simple sector-by-sector copy? Is she keeping it?
something of its own inside the service tags of the track?
Hello, Error404
Err> Why can't IS-DOS live on a simple sector-by-sector copy? What is she
Err> stores something of its own inside track service tags?
Can live. And it lives on images of 800Kb in size. You just have to take into account
that in order to be able to autostart from such disks via TR-DOS,
The sector size must be 1024 bytes. How can you find out the number of bytes in
sector and the number of sectors per track: In the case of a regular TRD file of size
640Kb we can set these values as constants. And in the rest
cases - you will have to attach a certain header with a structure descriptor to the file
track(s) - as a result, we logically approach the FDI file format,
which is precisely at first small (a couple of kilobytes) with
describing the sector structure of each of the 160 tracks, and then a simple
sector-by-sector copy of the entire disk.
Hello pbogdan
Not only is the sector 1024 bytes, but the numbering is also inconsistent -
There are 5 sectors on the track: 1st, 2nd, 3rd, 4th and 9th (!!!) ;) This is also for autostart.
So, instead of inventing your own, it’s really better to support
existing: TD0, FDI, UDI.
Hello jdigreze
This is the music, has anyone done this miracle? Pliz! On energy independent
can it be done? :v2_devil;
File:; Roms.txt http://zx.pk.ru/attachment.php?attachmentid=4456
File: romsch.JPG http://zx.pk.ru/attachment.php?attachmentid=4457
Hello, Scorpion(lv)
I "experimented" with this thing, but only in emulation (unreal). corrected
tyrdos, as in opisalov, set the breakpoints and threw sectors to him upon request;)
it worked (from a glitch I was able to launch a 2-sector boot). made for disk A.
By the way, in the description that I had, the dump and the listing did not partially coincide...
Hello skyther
There is such an idea: in the area of tyrdos ports, hang MK at 2 addresses
(commands/status and data), mms to it. At least write a procedure in Tyrdos
reading sector. I have chosen the ports so far: all even for commands, all odd for
data (I don’t really need real data ;) if you have any suggestions, write.
I'm also interested in opinions on the command system for MK. So far I've come up with these:
initialize the card, set the sector address, issue the next sector.