UNIX V7 is contained on a single RL02 disk image. To boot UNIX: ... Hope this helps!

From "Ryan Blair" <rblair(a)webteksdesign.com> Tue Jul 25 10:08:16 2000

From Warren Toomey <wkt(a)henry.cs.adfa.edu.au> Tue Jul 25 10:14:09 2000

In the same rut as Andy Valencia: I have tried booting the 2.11 BSD distribution that was in the boot images directory, it has something like 9 disc pack images, and a script to boot it with Supnik. Well, it boots all right, but I can't access most of the filesystem, just the root, and even there most of the files seem corrupt. It gets even worse when I try to shut it down. It will not even boot back up after I shut it down in the emulator.

From Greg Lehey <grog(a)lemis.com> Tue Jul 25 10:22:40 2000

In article by Ryan Blair: [Charset iso-8859-1 unsupported, filtering to ASCII...] I think all the 2.11BSD disk images in Boot_Images are suspect. I wonder if we could prevail upon Steven Schultz (or someone) to build some 2.11BSD disk images which would be suitable for the Supnik and Ersatz emulators.

From Jeremy Bingham <jeremy(a)mail.flyingcroc.net> Tue Jul 25 10:37:47 2000

From "Steven M. Schultz" <sms(a)moe.2bsd.com> Tue Jul 25 13:00:06 2000

From: Warren Toomey <wkt(a)henry.cs.adfa.edu.au> In article by Ryan Blair: I think all the 2.11BSD disk images in Boot_Images are suspect.

I wonder if we could prevail upon Steven Schultz (or someone) to build some 2.11BSD disk images which would be suitable for the Supnik and Ersatz emulators.

From "Steven M. Schultz" <sms(a)moe.2bsd.com> Tue Jul 25 13:18:29 2000

From: Jeremy Bingham <jeremy(a)mail.flyingcroc.net> I just acquired a MicroPDP-11 from a Goodwill a couple of days ago with a

RX50-A dual 400KB floppy and an RD52 31/33(?)MB hard drive, but it doesn't have a tape drive. My questions are:

1.) What UNIXes have been successfully loaded onto these types of machines?

2.) Can it be done without a tape? If so, has anybody pulled it off?

3.) Are there any utilities, either DOS or UNIX/Linux/FreeBSD based, to write and/or format RX50 floppies?

From maximum entropy <entropy(a)zippy.bernstein.com> Tue Jul 25 14:16:09 2000

Date: Mon, 24 Jul 2000 20:18:29 -0700 (PDT) From: "Steven M. Schultz" <sms(a)moe.2bsd.com> Hmmm, I thought John Wilson has some utilities that could do that. Normally you need to buy preformatted RX50 disks or have a DEC Rainbow (DOS) system around. On the other hand if the controller is an RQDX3 it is possible with some luck (and more hardware skill than I have ;)) hook up a standard 5.25" Teac floppy drive. I don't have the location of the info for that at hand - you might try the alt.sys.pdp11 or vmsnet.pdp-11 newsgroups (lots of knowing folks hang out there).

From barry(a)chezmoto.ai.mit.edu Tue Aug 4 08:14:38 1992 From: barry(a)chezmoto.ai.mit.edu (Barry Kort) Newsgroups: comp.sys.dec.micro Subject: Re: reading rainbow disks on a '386 PC Date: 2 Aug 92 11:53:41 GMT Organization: MicroMuse In-reply-to: keithr(a)garfield.cs.mun.ca's message of 1 Aug 92 01:10:53 GMT 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 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. 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. 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. 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. 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 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 From cosc16to(a)menudo.uh.edu Tue Aug 4 08:14:48 1992 From: cosc16to(a)menudo.uh.edu (Andy Hakim) Newsgroups: comp.sys.dec.micro Subject: Re: reading rainbow disks on a '386 PC Date: 2 Aug 92 19:45:22 GMT Organization: University of Houston X-Newsreader: Tin 1.1 PL4 barry(a)chezmoto.ai.mit.edu (Barry Kort) writes: : : 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. : : 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.) Another method of obtaining a formatted disk for the Pro-3xx, is to use an image copy program called Teledisk (shareware) for the PC. Not only does this program allow you to do a disk-to-disk copy, but it can also store a disk into a file (on the PC). This way, it is possible to keep an image file of a blank P/OS formatted disk, and then crank out new copies easily. In my experience, low density disks (360k) on a high density (1.2m) AT class drives seem to work out best. -andy From lasner(a)watsun.cc.columbia.edu Tue Aug 4 08:14:56 1992 From: lasner(a)watsun.cc.columbia.edu (Charles Lasner) Newsgroups: comp.sys.dec.micro Subject: Re: reading rainbow disks on a '386 PC Date: 3 Aug 92 06:39:56 GMT Reply-To: lasner(a)watsun.cc.columbia.edu (Charles Lasner) Organization: Columbia University Nntp-Posting-Host: watsun.cc.columbia.edu In article <1992Aug2.194522.18244(a)menudo.uh.edu> cosc16to(a)menudo.uh.edu (Andy Hakim) writes: Where can I obtain Teledisk? Does it require any low-level preformatting of the media on the target? IF you use DR-DOS and RAINDOS (but not RX50DRVR) you can use DISKCOPY and DISKCOMP to copy RX50 MS-DOS diskettes to each other, or to files on the hard disk: DISKCOPY E: C:\RX50DISK.IMG DISKCOPY E: E: DISKCOPY C:\RX50DISK.IMG E: DISKCOMP E: C:\RX50DISK.IMG When writing the file or disk image onto a target disk, the diskette has to be already formatted as a low-level RX50, yet there are no high-level considerations, so non-DOS RX50's can be directly used as targets! Of course input diskettes have to already be MS-DOS RX50 DECmate II/Rainbow diskettes because of DOS restrictions. Note that DOS 5 cannot do anything but "standard" disk sizes, and can't copy disk images to files at all. And without hub rings is better. If you suspect that a disk is actually high-density when it has no hub rings, there is a simple test: Just format it as a normal 1.2 Meg disk. a low-density diskette will get hundreds of Kbytes in bad sectors, while a HD diskette will get little or no errors, thus proving it unsuitable for RX50 purposes. Most disks with hub rings are already clearly low-density, but after you remove them, this will prove a quick check for actual diskette formulation. cjl From cosc16to(a)menudo.uh.edu Tue Aug 4 08:15:02 1992 From: cosc16to(a)menudo.uh.edu (Andy Hakim) Newsgroups: comp.sys.dec.micro Subject: Re: reading rainbow disks on a '386 PC Date: 3 Aug 92 16:42:35 GMT Organization: University of Houston X-Newsreader: Tin 1.1 PL4 lasner(a)watsun.cc.columbia.edu (Charles Lasner) writes: : : Where can I obtain Teledisk? Does it require any low-level preformatting : of the media on the target? : I checked the ftp site "wuarchive.wustle.edu", it is in directory "mirrors2/msdos/dskutl" as file "teled212.zip". Nope, this one does not require any low level preformatting. It's possible to stick in a brand new ds/dd and let it go. Incidently, teledisk is made by the same people, Sydex, who make 22disk. -andy From cosc16to(a)menudo.uh.edu Tue Aug 4 08:15:11 1992 From: cosc16to(a)menudo.uh.edu (Andy Hakim) Newsgroups: comp.sys.dec.micro Subject: Re: reading rainbow disks on a '386 PC Date: 3 Aug 92 16:54:30 GMT Organization: University of Houston X-Newsreader: Tin 1.1 PL4 : I checked the ftp site "wuarchive.wustle.edu", it is in directory : "mirrors2/msdos/dskutl" as file "teled212.zip". Correction, it's spelled "wuarchive.wustl.edu" with a missing 'e'. Host nic.switch.ch (130.59.1.40) Location: /mirror/msdos/dskutl FILE rw-rw-r-- 93805 Dec 23 1990 teled212.zip Host ftp.uu.net (137.39.1.9) Location: /systems/msdos/simtel20/dskutl FILE rw-r--r-- 93805 Dec 22 1990 teled212.zip Host wuarchive.wustl.edu (128.252.135.4) Location: /mirrors3/garbo.uwasa.fi/diskutil FILE rw-rw-r-- 94075 Dec 11 1990 teled212.zip Location: /mirrors/msdos/dskutl FILE rw-r--r-- 93805 Dec 23 1990 teled212.zip archie> From lasner(a)watsun.cc.columbia.edu Tue Aug 4 08:15:17 1992 From: lasner(a)watsun.cc.columbia.edu (Charles Lasner) Newsgroups: comp.sys.dec.micro Subject: Re: reading rainbow disks on a '386 PC Date: 4 Aug 92 05:55:11 GMT Reply-To: lasner(a)watsun.cc.columbia.edu (Charles Lasner) Organization: Columbia University Nntp-Posting-Host: watsun.cc.columbia.edu In article <1992Aug3.164235.1187(a)menudo.uh.edu> cosc16to(a)menudo.uh.edu (Andy Hakim) writes: Sydex also makes RAINDOS. I suspect that teledisk will only make sector-compatible descendents though, so if I have a specially layed-out version of a diskette (such as 2:1 interleave or staggered, etc.) the descendent will lose that aspect of optimization, and will instead become "vanilla" RX50 format in the case of RX50 diskette. The point is that certain software, especially for DECmates not specifically geared to CP/M-80, and *any* bootable DECmate diskette (including CP/M-80) the format used in stock RX50 layout is non-optimal. There are different requirements for different specific applications, but just as on PC's, the use of non-interleaved non-staggered disks can be demonstrated to be inferior to a variant in terms of sector ordering at the low format level. Rainbow MS-DOS disks have an implied software interleave of 2:1 for the FAT area, and 1:1 in the rest; this is in software, so the standard disk layout should be maintained, except that the *stagger* is not taken into account. Thus, like a PC, Rainbow MS-DOS disks should be formatted with a stagger of 2 per track. Thus track 1 is layed out 1,2,3,4,5,6,7,8,9,10 and track 2 is layed out 9,10,1,2,3,4,5,6,7,8. When the disk seeks from track 1 to track 2, it will thus miss 9 and 10, but immediately find 1. Were the stagger not there, it would miss 1 and 2, and reject 3,4,5,6,7,8,9 while waiting for 1 to come around again. Thus staggering relieves rotational latency. For the DECmate, there are two additional problems: All bootable diskettes require the logically sequential reading of tracks 78, 79 in the order 1,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,10. But the RX interface of the DECmate can't perform 1:1 interleave ever, so this is anti-optimal not only in stagger but more importantly in interleave. Thus, this area of the disk should be formatted with an interleave of 2:1 as well as a stagger of 2. Thus the disk is layed out: track 78: 1,6,2,7,3,8,4,9,5,10 track 79: 5,10,1,6,2,7,3,8,4,9 This restriction is based on the ROM routines that read in this area in linear order. This is mostly why all DECmates take so long to boot up! Changing to a better sector order will chop seconds out of the boot time. Further, all systems other than CP/M-80 require some form of help, mostly applying the stagger that helps the Rainbow as well (again other than CP/M). For DECmate MS-DOS, tracks 0-3 should be in 1-1 interleave because the software already maps the disk in 2:1 usage. tracks 4-79 should be formatted 2:1 interleave to help out the RX interface when the Rainbow-optimal ordering is invoked (similar to the DECmate ROM access, and just as inefficient on a DECmate). OS/278 does a software 2:1 interleave, so the only help needed is a disk-wide stagger factor of 2. Note that RT-11 and all other -11-oriented disks should use stock format only because this superior software maps all sectors to include both the 2-1 interleave and stagger of 2 already. So, if Teledisk is a *really* good utility, it won't disturb the format's stagger and interleave as it copies the disks! cjl From lasner(a)watsun.cc.columbia.edu Tue Aug 4 08:15:23 1992 From: lasner(a)watsun.cc.columbia.edu (Charles Lasner) Newsgroups: comp.sys.dec.micro Subject: Re: reading rainbow disks on a '386 PC Date: 3 Aug 92 05:39:27 GMT Reply-To: lasner(a)watsun.cc.columbia.edu (Charles Lasner) Organization: Columbia University Nntp-Posting-Host: watsun.cc.columbia.edu In article <BARRY.92Aug2075341(a)chezmoto.ai.mit.edu> barry(a)chezmoto.ai.mit.edu (Barry Kort) writes: 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. 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. 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?) 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. 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 >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 From lasner(a)watsun.cc.columbia.edu Tue Aug 4 08:15:29 1992 From: lasner(a)watsun.cc.columbia.edu (Charles Lasner) Newsgroups: comp.sys.dec.micro Subject: Good report on Teledisk. Date: 4 Aug 92 07:27:25 GMT Reply-To: lasner(a)watsun.cc.columbia.edu (Charles Lasner) Organization: Columbia University Nntp-Posting-Host: watsun.cc.columbia.edu I have down-loaded Sydex's teledisk, and have found it to exceed my expectations in some useful ways. For starters, all of my attentions are based on the problems of distributing RX50 diskettes not necessarily in stock format, and not yet having any satisfactory way of creating the necessary disks. Background: There are several desirable variant formats for RX50 that have been discussed elsewhere. The only known program to create them is FDFORMAT for PC's. While this freeware program is generally quite good, it has a few crucial bugs that make it unsuitable for RX50 usage. It is conceivable that this will be solved by using some additional/non-standard parameters to FDFORMAT to create usable disks, but in any case, the use of all obvious parameters yields disks that are flakey on some RX50's, and downright unreadable on others. In addition, these disks are so messed up that a DECmate can't even WRITE on the disks and read back what it just wrote reliably! Yet, this isn't a media problem because it can be demonstrated that the problem disappears by low-level format of the same diskette with either Sydex's RAINDOS or 22DISK packages. (Note that *some* RX50 systems using some newer-designed controllers and/or higher revision drives and/or RX50-compatibility modes on different drives have little or no problems with these FDFORMATted diskettes; indeed the diskettes are fine on a PC; there's some low-level detail that's incorrect about FDFORMATted diskettes. Some parameter is being set to a PC-acceptable value that doesn't center on RX50's requirements. Perhaps this will be uncovered at a later time obviating this entire discussion. Until such a time, FDFORMAT cannot be used to create RX50 diskettes that are readable on *all* RX50 systems. FDFORMAT also has a few other operational bugs, such as incorrect recognition of certain I/O errors, etc., but these are exception cases, and for all other PC purposes, it serves quite admirably.) The reason why FDFORMAT is desirable is that it is the only known program capable of creating the variant RX50 formats where the format must be done with interleave and stagger factors, especially if the disk must have "zones" where the format changes. For example, to create a disk best suited for DECmate OS/278 usage, the following *TWO* commands should be given: FDFORMAT A: /T:80 /N:10 /1 /Y:2 /I:2 FDFORMAT A: /T:78 /N:10 /1 /Y:2 The first command creates a disk with an interleave of 2:1 and a stagger of 2 throughout. The second command changes tracks 0-77 to have 1:1 interleave and a stagger of 2 throughout. When OS/278 is copied onto such a diskette, the "slushware" tracks are read in much faster than on standard RX50 diskettes, and all access to the rest of the diskette is speeded somewhat because of the stagger factor which overcomes the software's lack of stagger mapping. But since the software does map the sector order into a 2:1 interleave, the hardware order must stay in 1:1 interleave sequence. This would be a nice disk to use for the intended purpose, but many DECmates will be unable to read this diskette. Literally, it will get a CRC error on *every* sector! Furthermore, if you attempt to write an image of the software onto this diskette, it will get a CRC error on *every* sector even though it just wrote the disk out! Enter Teledisk to the rescue! When I read Teledisk's documentation, I had doubts that it could solve this problem, because I noticed it could be quite "smart", perhaps *too* smart! It claims that it can get around certain copy-protection methods by virtue of how it operates, so I figured that it would likely copy the problems of FDFORMAT as well :-(. Or, alternatively, it might guess that the diskette was an RX50 and proceed to format it in a stock manner, thus destroying the optimization applied by using the two FDFORMAT commands instead of just using RAINDOS or 22DISK to create stock low-level RX50 diskettes. Well, I was wrong on both counts! Teledisk understands how to maintain sector order, and pointed out the change of interleave from 1:1 to 2:1 at track 78, so that problem is hurdled. Teledisk understands that these sectors should be formatted with apparently the same parameters as the formatting routines in 22DISK and RAINDOS, so the resultant disk *is* readable on DECmates! Of course, this is *not* an "exact" copy, but rather it is a "better" copy. Apparently Teledisk only writes sectors in a "sane" format, and the copy-protection they refer to is the class of "funny" sector ordering, size, or count, not any lower-level details. Apparently the Sydex code at work in RAINDOS and 22DISK is also within Teledisk, thus since Teledisk recognizes the disk as a 10-sector/track 512 bytes/sector disk, it writes it as would RAINDOS, etc., except Teledisk is sensitive to sector ordering unlike the other Sydex programs, etc. Thus, the descendent disk is actually *better* than the original. I can now therefore distribute diskettes in the intended format for working-copy usage of the best effort of each diskette :-). Additionally, if I modify distribution diskettes to be in their intended format instead of their original stock format (virtually all diskettes that need to be distributed are in stock RX50 format, because the need to create optimal diskette layout is generally newer than the software; indeed, this entire effort is to distribute software that performs *better* than the original!), then the master disks should be copied with Teledisk to create perfect copies in one step. There are additional advantages: Teledisk can also create an MS-DOS file that is the image of the diskette in either a rudimentary-compressed or advanced-compressed form. These files can be transmitted down the net and then reconstructed on PC-AT's for use on RX50 targets. Since they are compressed, this minimizes the overhead as well, etc. So, Teledisk has made my day :-). cjl From barry(a)chezmoto.ai.mit.edu Wed Aug 5 10:12:06 1992 From: barry(a)chezmoto.ai.mit.edu (Barry Kort) Newsgroups: comp.sys.dec.micro Subject: Re: reading rainbow disks on a '386 PC Date: 4 Aug 92 12:13:30 GMT Organization: MicroMuse In-reply-to: lasner(a)watsun.cc.columbia.edu's message of 3 Aug 92 05:39:27 GMT Charles, You can retreive rt11.zip by anonymous ftp from newton.canterbury.ac.nz, 132.181.40.1, in the pub/local directory. Barry From lasner(a)watsun.cc.columbia.edu Wed Aug 5 10:12:14 1992 From: lasner(a)watsun.cc.columbia.edu (Charles Lasner) Newsgroups: comp.sys.dec.micro Subject: Re: reading rainbow disks on a '386 PC Date: 4 Aug 92 18:41:23 GMT Reply-To: lasner(a)watsun.cc.columbia.edu (Charles Lasner) Organization: Columbia University Nntp-Posting-Host: watsun.cc.columbia.edu In article <BARRY.92Aug4081330(a)chezmoto.ai.mit.edu> arry(a)chezmoto.ai.mit.edu (Barry Kort) writes: Got it. It looks nice. It produces what appears to be a nice RT-11-like environment on a PC for file transfers, etc., but is inferior to Teledisk for the purpose of making a compacted image of an entire disk as a DOS file. Since this is a frill, it can be completely overlooked :-). And yes, it does Format DD-type media to stock RX50 as advertised. I will only take you to task on the minor point: it doesn't require RX50DRVR at all. There was a little confusion as to whether they were tied together, which is not the case. This program is written in Turbo Pascal. It would seem that someone who can understand enough TP and the quirky code to call BIOS routines should incorporate some of RT11.PAS into FDFORMAT (also a TP-based item) since the format routine works fine while FDFORMAT does not for RX50 as discussed elsewhere. Overall a nice program. cjl

From lars brinkhoff <lars(a)nocrew.org> Tue Jul 25 15:55:00 2000

Hmmm, I don't think they're corrupt.

Wasn't there a similar posting a month or two ago about someone (I forget who it was) having "massive corruption". It turned out that the simulator was only told to use 256kb of memory (18bit mode). Once the "set cpu 2048k" command was added to the conf file the problems cleared right up.

Try putting "set cpu 2048k" (I don't _think_ you need both "set cpu 22b" and "set cpu 2048k" but having both doesn't hurt and may help).