How to get 720KB on Opus Discovery floppy (using PC drive)

edited August 2013 in Hardware
I upgraded an Opus Discovery yesterday with a PC drive, but I'm looking for the way to get a floppy formatted as 720KB.

If I understand other topics correctly, I should find a utility to achieve this.
There should be several utilities, but no topic shows the name or link to such a utility.
Where can I find such a utility?

Or is there some BASIC I can type in to perform the necessary changes to the Opus (ram)?

Then, if I found that utility, how can I get it to the Opus?
At this moment I only have pc's without internal floppydrive in use, but I do have USB drives.
Will SamDisk work on a USB drive under Windows7?

Maybe it's more easy to load the utility from tape/mp3 player.
Post edited by bverstee on

Comments

  • edited August 2013
    Hi Ben,

    I have done the same upgrade to my Opus years ago. If you manage to find a way to format 720K floppies please let us all know.

    Cheers
    As a young boy chasing dragons with my wooden sword so mighty
  • edited August 2013
    As long as its in .OPD format, then SAMdisk has no problem writing it (and formatting correctly at the same time) to a disk. Otherwise as you mentioned, its probably a case of loading it into the Speccy if it is a suitable .TAP/.TZX format and SAVEing it out block by block with altered BASIC lines for loading from disk. Maybe theres better or different support in the newer ROM I put a link to a few minutes ago? I have no associated instructions relating to it. I seem to recall a discussion here in the forums last year where someone from the SUCsession (I think!?) group suggested the ROM and seemed to have knowledge of it. It operates much faster than the older OPUS ROMs and includes some other features possibly. Hope this helps.
  • oboobo
    edited August 2013
    bverstee wrote: »
    Will SamDisk work on a USB drive under Windows7?
    No, it won't work with USB floppy drives. That said, since the drives do still support 720K and 1.44M formats, I could probably add support for writing just those image types to them...
  • edited August 2013
    Hey Ben, in this link you'll find all the stuff you need, better use an emulator to run through disks. Also I have a lot of thinks roko send me but not yet found the time to catalogue them. http://web.tiscali.it/spectrumnostalgia/comme.html

    Hope that helps.
  • edited August 2013
    Guess I have to get that old laptop with integrated floppy from the dust-shelves ;)
  • edited August 2013
    Never throw anything away!!
  • edited August 2013
    The specifiications of each disk (drive) is stored tables in the 2K RAM. The specs for a disk is written down in the bootsector, and is copied from there into the tables during each 'Inquiry' that preceeds all disk activities.
    This 8192,300 block of data can be saved to and loaded from disk. And changes can be made in between, f.e. you load it temporarely to 30000.
    The table layout can be found in the ROM disassembly available on WOS. As a first step all you need to change is 40 in to 80. (Note that there are 4 equal tables.)
    There were several programs available for the job. I must have several, somewhere in my piles. Lately the one from Helge Keller (Lily Soft) was dicussed here. I believe.
    Most programs also allow to change the interleave factor, for the next disk to format. (See quickdos)
  • edited August 2013
    There is quite a difference between Opus disks and other. Not only the sector size, 256 in stead of the usual 512, but Opus starts off a track with sector 0 while most others start with 1. And Opus checks the bootsector (tr.0 sct.0) for the 2 byte jump over the disk-specificatons table residing there. which table is copied in RAM 6116.
    The Opus system can use sector length up to 1 (or was it 2) Kb, all the standard IBM3820(?) values. But large buffer sizes prevent the loading of large files.
  • edited August 2013
    roko wrote: »
    There is quite a difference between Opus disks and other. Not only the sector size, 256 in stead of the usual 512, but Opus starts off a track with sector 0 while most others start with 1. And Opus checks the bootsector (tr.0 sct.0) for the 2 byte jump over the disk-specificatons table residing there. which table is copied in RAM 6116.
    The Opus system can use sector length up to 1 (or was it 2) Kb, all the standard IBM3820(?) values. But large buffer sizes prevent the loading of large files.

    Ok, it does dazzle me a bit, but let me try to get this clear in my head:
    The disk specs for each separate disk are stored on the disk?
    And the Opus reads and stores these specs everytime it accesses a disk?

    That's quite different from what I'm used to with every other system (PlusD, MB02, etc), where the disk specs are read only once: from the system file.
  • edited August 2013
    So basically, it looks as if its a highly customizable system that can have any number of disk formats all unaffected by the hardware itself?
  • edited August 2013
    jamorski wrote: »
    So basically, it looks as if its a highly customizable system that can have any number of disk formats all unaffected by the hardware itself?

    That's exactly what I mean, with the disadvantage that it's (very) unclear to new users where to start / what to do, especially with those differences in the roms.
    Maybe the top of the Opus case should be used for a 'getting started' guide ;)
  • edited August 2013
    Though in many ways the actual disk 'size' and format is transparent to the user, as the system determines by itself how its going to work with the specific disk in use. If you LOAD or SAVE etc, the OPUS will do what it needs to based upon the disk structure table plonked in memory at the outset of every disk operation. That is of course if I'm understanding everything (almost) correctly?
  • edited August 2013
    bverstee wrote: »
    The disk specs for each separate disk are stored on the disk?
    Yes, 99.9%. The CAT size is left out, but the CAT file uses an endmarker anyway and can have any size after a poke in the RAM table.
    bverstee wrote: »
    And the Opus reads and stores these specs everytime it accesses a disk?
    Correct. Even this 'copy-the-table' program is in the boot sector. In fact one could easily be tempted to write very clever (or very nasty) stuff.... I believe I made a disk that did a CAT every time it was inserted, showing files that did not exist in real. Silly jokes.
    bverstee wrote: »
    That's quite different from what I'm used to with every other system (PlusD, MB02, etc), where the disk specs are read only once: from the system file.
    Opus was expensive, slow, and could not load all games due to the sector buffer taking Spectrum RAM away. In all other aspects it was the best, under the hood, IMHO. Modular to the hilt, and consistant. Resulting in an elaborate system of tables holding all 'hook' entries. Which scared most users away, I am afraid....
  • edited August 2013
    jamorski wrote: »
    That is of course if I'm understanding everything (almost) correctly?
    Yes you do.
    P.e. in my copier program for 720K DOS disks is Opus handling the fetching of 512 bytes sectors (1-9) all by it self. The program merely does the (FAT) bookkeeping, and the sending out of 256 bytes sectors (0-17), or whatever layout the receiving disk may have.
  • edited August 2013
    I must say: I think some of this is too complex for the use that most users are looking for (nowadays).
    Back in those days the main user group existed of people whose only desire it was to understand the technique to it's deepest details, and the Opus Discovery offered that challenge ;)

    It's great that some understand these techniques completely and I love reading about it.
    People like you are needed roko, even like those who develop the modern operating systems.
    However IMHO end-users shouldn't worry about this complexity, but only about how to use the system in a simple way.

    I mean: I still haven't had a simple awnser to my question about how to format a 720KB disk on an Opus Discovery haha!
    I will download the tools from the website that Pluto63 showed, hoping one of them can be used to achieve the 720KB format.
  • edited August 2013
    Hi Ben,
    bverstee wrote: »
    I must say: I think some of this is too complex for the use that most users are looking for (nowadays).
    ...
    However IMHO end-users shouldn't worry about this complexity, but only about how to use the system in a simple way.

    I think, people who are looking for a simple system without need of special knowledge can use Wintel PCs , Smartphones, Emulators or for example one of those simple to use divIDE interfaces together with a Spectrum.
    People who like to use an experimental computer with the flair of those "first days of (home) computing" should try to understand their system a bit, because it is not that complex and that type of technical understanding keeps that old systems living.

    Greets Ingo.
  • edited August 2013
    bverstee wrote: »
    I mean: I still haven't had a simple awnser to my question about how to format a 720KB disk on an Opus Discovery haha!
    Yes, problem understood and agreed.
    But then, you did not tell whether you want double/single density, double/single side, write compensation On/Off, head settling delay On/Off, Deleted Data Mark Yes/No, enabled or disabled Spin-up sequence. Nor did you mention the steprate of your drive, the number of sectors and number of tracks you want, and even forgot the skew and interleave factor. (Haha....) :-):smile::smile:

    The problem is Ben that these are the issues to address when people want to go beyond the system as standard sold. Sometimes new standards are settled. Like you do when you decide to sell Opus 'standard' with 2.2 ROM. And another new standard is already on it's way when you determine "what end-users want these days". Do not misunderstand :I fully agree that you are in the position where making up such decisions is necessary. For the end-users....

    Like you say, there is another group. Those who use a hobby to think and to tinker outside standards. Those who like getting information and then go and discover their own way. There are several here around and indeed, I am among those.
    So the info I give is not exclusively ment for you, so to speak.

    To the point then, here is the simplest method if noone else turns up:
    (for DOS 2.22 + 6116Ram, the final DOS from Opus)

    10 OPEN# 4;"CODE": POINT# 4; 8248: REM enter CODE as keyword
    20 PRINT #4; CHR$ 80;: REM note the semicolon !!!!!!
    22 POINT# 4; 8250
    24 PRINT #4; CHR$ (BIN 01001110);: REM semicolon !
    30 CLOSE# 4
    40 FORMAT 1;"diskname": REM (assuming a DS 80tr drive being drive 1)

    (A ROM 2.22 is going your way in a minute. It features a steprate better suited for modern drives, and a Ramdisk for Spec128, and extended CLS and ERASE commands. You also could wait till the meeting in Maarssen, 17th of aug., then I could fix it for you. :-) )
  • edited August 2013
    That's it!? That is so easy to do! So once FORMATed, the disk is usable in the normal way, but just with 720KB? Brilliant!
  • edited August 2013
    I think the MGT boys found using streams & channels for GDOS RAM access too difficult to implement. That's why we have POKE @. The Opus system is much more flexible....

    @roko:
    So FORMAT doesn't do an inquire?
  • edited August 2013
    Rudy wrote: »
    @roko:
    So FORMAT doesn't do an inquire?
    Indeed, the logic consequence. (haha, good question, almost, I had to check this one...)
    After coldstart the disk tables in ROM are copied to RAM so RAM holds the default specifications (40 tr., 180Kb, etc). These default values are replaced by 'real' disk specs as soon as a disk is approached other than by FORMAT. The format command direct takes the specs from the RAM table if the chip is installed.
    On many (most?) Opusses the RAM was not installed, so there also is a flag signalling the use of the ROM, or the RAM table. Opusses without RAM chip have to use the default ROM table anyway.
  • edited August 2013
    roko wrote: »
    Indeed, the logic consequence. (haha, good question, almost, I had to check this one...)
    After coldstart the disk tables in ROM are copied to RAM so RAM holds the default specifications (40 tr., 180Kb, etc). These default values are replaced by 'real' disk specs as soon as a disk is approached other than by FORMAT. The format command direct takes the specs from the RAM table if the chip is installed.
    On many (most?) Opusses the RAM was not installed, so there also is a flag signalling the use of the ROM, or the RAM table. Opusses without RAM chip have to use the default ROM table anyway.

    So that's why you need the 6116 chip to be able to format other than 180KB: the specs table stored in ram can't be modified, but in ram it can.
  • edited August 2013
    Finally I found out how it works, thanks to my friend Roelof Koning here in the Netherlands.

    Roelof sent me some Opus Discovery disk image files and a Windows utility called 'Vimaging.exe' which can extract files from Opus Discovery disk image files.
    After extracting I converted the .tap files that were created to mp3, and loaded the mp3 into a ZX Spectrum with real Opus Discovery using an mp3 player:

    20130807_194927.jpg

    That worked great!

    The First tool was a formatting utility from Helge Keller, but the code file was missing unfortunately, so I couldn't use that one.
    However it showed some disk format specs by default for a double sided disk with over 80 tracks!

    20130807_202155.jpg

    The second one was a tool from Axel Toepfer, and that one worked great!
    First I thought: let's try to use the disk format specs from the other tool:

    20130807_202432.jpg

    But that didn't work properly, probably the 11 sectors per track were invalid:

    20130807_202712.jpg

    So I changed the configuration to that from a PlusD/Disciple/Sam Coupe disk:

    20130807_202759.jpg

    And that workd 100%!!
    I quickly created a BASIC program that saved 10K files, and it stopped at 80 files as expected:

    20130807_204025.jpg

    20130807_204040.jpg

    So it's amazing that the Opus Discovery is this flexible: you can change disk format specs to any configuration you want, even more than default numbers of tracks etc.
    When such a formatted disk is used, the Opus Discovery rom detects the format and uses it.

    However that causes some problems: Roelof told me he still wants to upload some disk images to WoS, but it's hard to convert a disk image with a non-standard format.

    Anyway, I'm very happy having learned such a lot about the Opus Discovery!
    What a great invention!

    And then to know the company (Opus Supplies) still exists!
  • edited August 2013
    The 11 sectors of 512 bytes simply do not 'physically' fit on a track, when the so called 'gaps' have the usual sizes. 'Gaps' are three blocks of identifiers (for bookkeeping purposes) that are stored between data blocks in each sector. The minimal size of these gaps is not rock solid fixed but is still connected with reliability. So systems with 11x512 can exist. On Opus the formatting sequence is found in tables in ROM. And yes, these can be replaced...
    Sorry, I might be delving too deep now :-). But I have good memories of those days...
  • edited August 2013
    bverstee wrote: »
    However that causes some problems: Roelof told me he still wants to upload some disk images to WoS, but it's hard to convert a disk image with a non-standard format.
    Due to the size of diskimages (180,360,720K) the creating should be done on PC. The available imaging programs expect 40 tracks. Many other progs expect a sector size of 512, or maximal 10 sectors on a track. My own home made program did not show enough reliability, this could be related with PC hardware. The usual dilemma, and I left it there.
  • edited August 2013
    Hi Roelof,

    do you know http://www.dubaron.com/diskimage/ ?

    I use this program for a long time for example to get diskimages from my mb02+ compact flash cards. The program does bitwise reading without care about the disk configuration.

    Greets Ingo.
  • edited August 2013
    Thanks Ingo,

    Checking this prog will be on my list.

    Talking about Compact Flash cards I find this one very usefull as it can handle my private soft-defined 'partitions'. (WinXP)

    www.mikrocontroller.net/attachment/47409/SD_RAW.exe
  • edited August 2013
    It would be great to get Opus Formatter and Super Format in the archive, unless they already are and Infoseek is being unhelpful today!?
  • edited August 2013
    They are PD and should be there. When I find the time...
  • edited August 2013
    I was looking for a simple but well working copy program.
    The standard MOVE command won't work with different disk formats:
    MOVE "d";1 TO "d";2

    So I needed something else.
    I found some copiers on disk but they simply didn't work or behaved very strangly.

    So I continued my search and I found a simple but great working copy program that can be typed in by yourself.
    I found it in a Discovery User Club magazine.

    I'm a bit lazy, so here it is ;) :

    CATmover1.jpg

    CATmover2.jpg

    I modified mu version a bit to copy disk to disk automatically.
    So it is copying (and the Opus isn't fast), and I can do something else in the meantime ;)

    I must say: it surprises me that there is almost nothing on WoS about the Opus Discovery.
    There has been a large user community here in Holland, but it seems only a few of them (like Roelof) are on WoS to help with Opus issues.
    Let's change that ;)
    I have three of them (well, at this moment, as I will offer them for sale lateron) and often get requests from other owners about the PC drive upgrade, and for software.
  • edited August 2013
    Working on a manual that describes the upgrade proces:
    http://benophetinternet.nl/hobby/vanmezelf/Upgrading%20your%20Opus%20Discovery%20with%20a%20PC%20drive.pdf

    I have the feeling that there is more interest in this.
    Pricing for an upgrade set follow later today.
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