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- In article <BARRY.92Aug2075341@chezmoto.ai.mit.edu> barry@chezmoto.ai.mit.edu (Barry Kort) writes:
- >I use the RX50DRVR on my AT which allows my 1.2 MB drive to read RX50
- >diskettes. What this does is to create a new driveletter (F:) which
- >spins the HD drive as if it were an RX50 drive.
-
- RX50DRVR, like RAINDOS, creates a new logical drive past your last existent
- drive, so it's F: for you because you apparently have an A: through E: before
- the driver gets loaded in CONFIG.SYS.
-
- >
- >RX50DRVR does not know anything about the directory structure on
- >the disks. If I do 'dir F:' it assumes DOS directory structure,
- >which works fine on Rainbow diskettes, since they use the DOS
- >directory structure.
-
- That's not quite true, since the disk organization has to be DOS as implemented
- on DECmate II MSDOS/Rainbow MS-DOS only. It is true only in the sense that
- you can make your own BIOS calls to read the disks yourself without caring
- about the significence. But that's no different from doing so with any
- floppy on a PC.
-
- >
- >To read RT11 formatted diskettes, there is a utility called RT11
- >which groks the RT11 file structure. I have not yet found a similar
- >utility which handles the RMS-11 file structure of the PRO 3xx series.
-
- Where can I get this RT11 utility? It sounds useful. Does it specifically
- require/recognize the RX50DRVR or does it merely work in an innocuous way
- with the same drive letter? (Would it work also with A:? or must it have
- RX50DRVR present. If so, would it work with RAINDOS as an alternative?)
-
- >
- >I can use Norton Utilities with RX50DRVR to examine the RX50 diskette
- >in the F: drive, but then I am accessing the diskette sector by sector,
- >not by logical file.
- >
- >I haven't explored the new utilities from the gentlemen in the Former
- >Soviet Union who have announced some DOS environment tools for
- >manipulating RX50 diskettes.
-
- Re the Soviet-originating files:
-
- The files come with a piece of shareware originating in Italy that intercepts
- DOS's calls for formatting commands, so that "odd" sizes, such as using:
- FORMAT A: /T:80 /N:10 are now legal. The result is a double-sided disk that
- is quite suitably low-level formatted for RX50, but the high-level is PC
- compatible, *not* DECmate/Rainbow's idea of MS-DOS, and specifically must be
- used on a "normal" drive and *not* with RX50DRVR. All media indicators are
- stock PC-type, not RX50. However, since the low-level is now correct, and
- errors are recorded in a way that FORMAT indicated when it finished, and can
- be re-confirmed with CHKDSK, etc., the media can be determined to be error-
- free hopefully. If so, then the companion program RX50INIT that comes with
- RX50DRVR can be used to initialize the directory so DECmate/Rainbow MS-DOS
- likes the disk, and of course the RX50DRVR-controlled logical device such as
- F: in your example. Note also that RX50INIT can be used with RAINDOS as well.
- Also, RX50INIT requires ANSI.SYS be loaded purely for cosmetic reasons.
- RX50DRVR and RX50INIT were designed for DOS 3.3 usage. They don't support the
- extensions to DOS brought into versions 4 and 5, so there are some problems.
- RX50INIT fails totally in those two systems, and CHKDSK can't work there
- either. With some adjustment to the BUFFERS= statement in CONFIG.SYS, they
- can be made to work for read/write purposes under DOS 4 or 5.
-
-
- When used with DR-DOS 6.0, all RX50DRVR and RX50INIT functions work fine.
-
-
- >
- >Using RX50DRVR in combination with the RT11 utility program, I can
- >low-level format a blank HD diskette as an RX50 diskette, then
- >put it in the PRO and do a high-level RMS-11 style Initialization.
- >This allows me to create new RX50 diskettes out of plain old unformatted
- >or recycled 1.2 MB HD diskettes.
-
- Just a word about using HD media:
-
- You can't reliably use HD media on an actual RX50, because the coercivity
- is too far off in HD media. It was designed for the higher-frequency
- recording of the "real" 1.2 Meg format (500 KHz) and not the 250 KHz recording
- rate of the RX50, which is actually the same as good 'ol DS/DD media (360K
- kid of media). Some revisions of RX50 drive in comination with certain RX
- controllers in some DEC machins fare better than others, but it can be
- demonstrated that a lot of combinations don't particularly "like" HD
- media.
-
- The designated media for RX50 is Maxell MD1DD-RX50 or equivalent, which is
- what used to be called "quad" media. This is well-honed low-density media,
- so it is rated for use on 96 TPI (80 track) drives, not just 48 TPI (40 track)
- drives as is usual. Note that MD2D is not MD2DD. (The 2 just means two-sided
- which for all intents and purposes today can be ignored; virtuall *all* media
- is actually made double-sided :-).) The DD means 80-track support, but since
- most media are made well-honed, most cheap disks can support 80 tracks anyway.
- These disks will *not* cause I/O errors on any RX50! However, long-term usage
- requires the hub rings be removed completely (use alcohol to get the sticky
- stuff off, or ask your supplier for no-hub disks!). Failing to remove
- hub rings means eventually the disks will get unreliable sooner than they
- ought to due to registration problems. All 96 TPI disks have this problem.
- Note that MD2HD and MD1DD don't have hub rings! It is rumored that there is
- a "premium" line of diskettes from Fuji apart from their standard line of
- inexpensive diskettes that has a specially reinforced hub area, that isn't
- a hub ring per se. If the same mechanism is used in both HD and DD media,
- then the DD type would be the best thing today to use with impunity for
- RX50. Clearly the MD1DD or MD2DD or MD1DD or the 3M equivalents are too
- expensive, considering that what we want are the cheapest types of diskettes
- with the hub rings never added. (We don't want to pay more for less!)
-
- Re RT-11 utility:
-
- I don't know anything about the RT11 utility program, but RX50DRVR cannot
- format disks; the code lacks support for the FORMAT command, and also some
- calls needed by both CHKDSK and FORMAT. Attempts to use either on DOS 4
- or 5 will get error messages. Even on 3.3, where CHKDSK is more "forgiving"
- you still get the message about "format not supported on device" when
- using RX50DRVR. So, if your claim for formatting is true, the RT11 utility
- must contain low-level formatting code of its own, and perhaps only needs
- RX50DRVR to locate the proper device?
-
- RAINDOS is a share-ware mostly superset of RX50DRVR, and it totally supports
- CHKDSK and FORMAT in DOS 4 and 5. It works fine with RX50INIT (assuming that
- RX50INIT can work!) and suffers from only two known problems:
-
- 1) Should you specify a format command with the FORMAT F: command,
- and the O/S is DR-DOS 6, then if it really does attempt a low-level format,
- it gets a cryptic error message and fails. Note that MS-DOS 5 and DR-DOS 6
- will always attempt a "quick" format if possible, unless over-ridden. This
- case of a quick format doesn't fail, but also isn't formatting! Just
- rewriting a cleaned-up high-level format directory initialize.
-
- 2) It is sometimes strangely slow, as compared to RX50DRVR where both
- could work. When using Norton 4.5's DT program, RX50DRVR handles the
- disk at normal speed, and allows DT to mark bad clusters (if any) quite
- nicely. When RAINDOS is used, it causes many recalibrates for unknown
- reasons. In some cases, the sloth isn't that noticeable, but this is a
- sore point usage.
-
- Otherwise, RAINDOS is a total replacement for RX50DRVR, or so it would seem.
- Norton NU treats RX50DRVR diskettes and RAINDOS diskettes equally since it
- does one-sector I/O.
-
- >
- >Using Venix on the PRO, I can do a raw image copy of a diskette in one
- >drive to a blank diskette in another drive. (This kind of copy will fail
- >if the target diskette has any bad sectors, since there is no attempt
- >to rearrange sectors to detour around any bad blocks.)
- >
- >Finally, by hooking up the PRO to a Unix or DOS machine via the
- >COM port (or to a Unix host via Ethernet/DECnet if you have a DECNA
- >card), you can transfer files via any number of techniques, ranging
- >from straight ASCII upload/capture using ordinary terminal emulators,
- >Kermit file transfers if you have Kermit on both machines, or by
- >DECnet file transfer using NFT or dcp utilities.
- >
- >None of this is particularly trivial to implement, but the bottom
- >line is that there are many ways to pull files off RX50 diskettes
- >and transfer them to Unix or DOS machines.
- >
- >Barry Kort
-
- If the Soviet files prove to work, and apparently requiring the Italian
- TSR shareware program, we can probably make Files-11 RX50 diskettes as well.
- I have just received these programs and will be evaluating them when feasible.
- I am still working with the accompanying Italian shareware which has some
- interesting "generic" features of its own with respect to the entire RX50
- issue. I suspect that its presence enhances any of these utilities, although
- it's possible redundant and perhaps extraneous to some of the utilities.
-
- In any case, there are many ways to get files moved around.
-
- Another excellent package is 22DISK from Sydex, the same shareware author
- as RAINDOS. This package low-level formats RX50's in either DECmate CP/M-80
- or Rainbow CP/M-80/86 format. (They are similar, but not identical, although
- they can read each other's disks no sweat; it's a matter of interleave, etc.
- and a throughput issue, not a format per se issue.) It then high-level
- formats the disks for CP/M usage. So, its a good place to do the low-level
- formatting required for all of these other utilities. For example, on
- DR-DOS 6, you first run 22DISK to format the disk, then use RX50INIT to get
- an RX50 MS-DOS DECmate/Rainbow high-level structure, and then can use
- RAINDOS to transfer files, run CHKDSK, and do quick-formats with FORMAT /Q,
- etc. Notice this avoids all of the Raindos/DR-DOS interaction :-).
-
- 22DISK can get directory listings of CP/M disks, and can transfer files
- to/from MS-DOS from/to the designated CP/M diskette. It supports literally
- hundreds of CP/M formats, which implies many low and high-level support
- variants. This program is highly reminiscent of the former Rainbow, and
- later PC-based "Media Master" program, but is for PC/MS-DOS only, and
- requires HD drives for the RX50 formats.
-
- I believe there is an obscure PRO option for a CP/M-80 board, so this might
- be yet another way to get files in/out of a PRO.
-
- So, like cats, there are many ways to "skin" an RX50 :-).
-
- cjl
-
-