RX50 Disk Imager for the Rainbow

[PrintStar]

As part of my entry for this year's RetroChallenge Winter Warm-Up, I've created some disk imaging utilities for the Rainbow 100. Specifically, the utilities can create RX50 images from disks, or write disks from RX50 images, similar to dd on GNU/Linux and rawrite on Windows/DOS. The utilities are downloadable from my blog.

The image writing utility is completely compatible with disk images converted from Teledisk format using the wTeledisk utility. While the utility was designed for and tested with Rainbow disk images, it should work fine with any RX50 image or disk.

The whole reason behind writing the utility is that I have plenty of Rainbows but a severe lack of computers capable of running Teledisk. While GNU/Linux can be used (somehow...) to write out the RAW RX50 images, the procedure seems to be hit-or-miss.

Hopefully the utilities will be useful to some of the DEC folks. Enjoy!

 

[Micom 2000]

I have a DEC 350 Pro which has the PASSWORD problem. The Pro boots and then demands the user name and password. Many Pro enthusiasts suggest never using that option. :^)

I've had it several years and tried all the default entries to no avail.
The usual solution offered is to erase the file containing the password entry. That means entering the computer from the fdd and so far I've had no luck. Suggestions are from using J Wilson's Putr emulator to using a copy of POS with the "Tools" utlity. That means using a hi-density 5.25 fdd to put on a disk.

The best site I've found regarding this problem is:

http://www.eskimo.com/~nickz/dec.html

I'm wondering if I could use teledisk (if needed) and your Disk Imager to make a bootable RX50 disk. I have a stash of DEC-formatted blank disks as well.

Lawrence

 

[PrintStar]

Suggestions are from using J Wilson's Putr emulator to using a copy of POS with the "Tools" utlity. That means using a hi-density 5.25 fdd to put on a disk.

The best site I've found regarding this problem is:

http://www.eskimo.com/~nickz/dec.html

I'm wondering if I could use teledisk (if needed) and your Disk Imager to make a bootable RX50 disk. I have a stash of DEC-formatted blank disks as well.

Lawrence

I'm not quite sure I understand the full problem, but if you need to write an RX50 disk image to an actual RX50 disk, this imaging program is perfect (provided you have a Rainbow). Because the image writer runs on a Rainbow, RX50 formatted media aren't necessary; a standard DSDD 360KB disk will work fine.

So you'll need to get a disk image with the POS and "Tools" in the image already. The image writer requires a raw disk image. If you have a Teledisk image, this can be created using wTeledisk. I'm not too familiar with Putr, so I'm not sure what kind of disk images it uses.

The image file should be exactly 409,600 bytes, the size of an RX50. The size itself means the Rainbow will need either a hard disk or a 720KB 3.5" floppy drive to hold the image for writing.

I'll be happy to provide any further help! Hope the utilities are useful!

 

[Micom 2000]

Well the bottom line is that I have a DEC Pro 350 which powers up and then demands the login name and password. An old problem which I have to solve regularly on my NEXT's after not using them for awhle and the attached slip of paper with logon and password has fallen off. I hate passwords, but it seems in those machines which were targetted at the corporate market, they are obligatory. This same problem is what discouraged me with Linux after numerous installations on Dos-boxes. I've sinced learned there is a means to do an installation with-out passwords on Linux, but it is awkward and compounded by the numerous machines I have and networking demands..

Of course the DEC Pro was a recovered machine so remembering the login-name and password isn't an option. I think that there were 2 different installatons, depending on whether it had an HDD or not, so it doesn't have first access depending on the configuration like MSDOS. The RX50 format and POS operating system (commonly referred to as Piece Of Shxx) complicates the problem more. It has been said that the Pro will also run the PDP OS's which might allow you to remove the Password file.

So somehow I need to gain entry to the Pro and either remove the offending file or reformat the HDD and then reinstall POS or RSX. Possibly I could remove the HDD and then use a boot disk to fire it up and install an HDD once I had it operating. And then there's the problem of downloading the various files on a MS box and then creating a boot disk in RX50 format that can be read by the Pro.

Interestingly I have a Deskmate folio binder I acquired, missing the OS disks but had an "Exploring the Deskmate" disk and several Deskmate Word Processing program disks. My Rainbow would read the Explore disk but choked understandibly on the WP disks since they had different processors. The "Explore" disk could have been retitled "Exploring the Rainbow" since the images and descriptions of the hardware were the same. This raises the question of whether there was some lower level common DEC language that the Rainbow, Decmate, and possibly the Pro could understand.

If you want a copy of this disk, I could make a copy on the Rainbow, or else with coaching, send it on the internet.

Lawrence

 

[PrintStar]

Well, I would download POS from the xhomer site. These floppy images are already in the proper format for use with my imaging program. Transfer the images to a Rainbow (probably via serial cable) and run the image writer, iwrite.exe, under MS-DOS version 2.11 or higher.

As for the computers having some common underpinnings, I would guess that the DECmate stores files in either a CP/M filesystem or FAT. Other than possibly similar file systems, similar cases, similar power supplies, and some shared disk controller chips, the DECmate, Pro, and Rainbow have almost nothing in common and feature wildly differing architectures. Each of the three were designed by independent teams at DEC, and there's evidence to support the fact that they weren't integrated. For example, Rainbows can low-level format RX50 media, which flies in the face of DEC policy of requiring preformatted disks. The Pro and the DECmate don't have this capability.

 

[Micom 2000]

From what I've read in the Byte reviews of the time, even the first issue of Rainbows were incapable of formatting floppes in the RX format. DEC responded to the criticism by allowing later versions to format floppies. That also led to the common solution of using Rainbows to format RX floppes for many DEC products including DecMates, Pros, and even Vaxes. Take that you vulturous marketing teams.

Thanks for the lead-thru. Once I get some form of order to my present collector chaos I'll report-back whether that works.

Lawrence

 

[Sharkonwheels]

From what I've read in the Byte reviews of the time, even the first issue of Rainbows were incapable of formatting floppes in the RX format. DEC responded to the criticism by allowing later versions to format floppies. That also led to the common solution of using Rainbows to format RX floppes for many DEC products including DecMates, Pros, and even Vaxes. Take that you vulturous marketing teams.

Thanks for the lead-thru. Once I get some form of order to my present collector chaos I'll report-back whether that works.

Lawrence

I dunno about you guys, but I just use teleDisk, with either a 1.2MB floppy, or lock the floppy manually to 300rpm (certain Teac FDD's), or a real DS/QD 5.25" FDD in the imaging PC. That's how I made disks for my RB+. If you happen to have a CompatiCard IV, I think it supports it, and if you happen to have an FDADAP from dbit.com, it has a port to connect an RX50 directly to a PC, as well as 8" drives.

Also, wasn't there also a device driver out there that you load, and it treats your 1.2M FDD like an RX50? It's simply a SS/QD disk, isn't it? 1S 80T 9SpT?
Yep, it's in this ftp folder. rx50drvr.sys and rx50.doc, rx50init.com for formatting. It creates a phantom drive letter for accessing rx50 format disks.

T

 

[PrintStar]

I dunno about you guys, but I just use teleDisk, with either a 1.2MB floppy, or lock the floppy manually to 300rpm (certain Teac FDD's), or a real DS/QD 5.25" FDD in the imaging PC. That's how I made disks for my RB+. If you happen to have a CompatiCard IV, I think it supports it, and if you happen to have an FDADAP from dbit.com, it has a port to connect an RX50 directly to a PC, as well as 8" drives.

I haven't been able to get Teledisk to work on any computer faster than a 486SX/25. Some people have had success, but modern floppy controllers are unreliable wrt Teledisk. Not having a working IBM PC-compatible machine in the 8088 thru 486 range pretty much means I can't use Teledisk. I've tried countless times, but no luck. There is some short explanations on Will's site.

I also don't have any of the hardware you mentioned above, nor do I have any desire to spend money on it when, in theory, I have plenty of machines that can read and write RX50s (they're all Rainbows).

Also, wasn't there also a device driver out there that you load, and it treats your 1.2M FDD like an RX50? It's simply a SS/QD disk, isn't it? 1S 80T 9SpT?
Yep, it's in this ftp folder. rx50drvr.sys and rx50.doc, rx50init.com for formatting. It creates a phantom drive letter for accessing rx50 format disks.

Yes, I've used those programs before, but they suffer from exactly the same problems as Teledisk; namely, they kinda/sorta/don't work on modern hardware, such as Pentiums and higher. Furthermore, those drivers allow you to read and write MS-DOS formatted RX50s; they don't allow you to create system disks or deal with floppies from CP/M.

I basically had a problem (couldn't write Teledisk images), so I fixed it by writing these imaging utilities.

 

[PrintStar]

From what I've read in the Byte reviews of the time, even the first issue of Rainbows were incapable of formatting floppes in the RX format. DEC responded to the criticism by allowing later versions to format floppies. That also led to the common solution of using Rainbows to format RX floppes for many DEC products including DecMates, Pros, and even Vaxes. Take that you vulturous marketing teams.

I think it was even simpler, but I'll have to check. My understanding is that the operating systems released when the 100A came out wouldn't allow you to format floppies, but later versions of the OSes allowed it, even on the 100A. The technical documents for MS-DOS 2.11 on the 'bow show a BIOS hook for formatting RX50 sectors, but make no mention of the call not working on a 100A. I'll have to see.

From what I've heard, DEC wasn't responding to criticism that it couldn't format floppies. Otherwise, every DEC machine would have been fixed to allow it. The actual Rainbow engineering team was apparently annoyed to no end that they couldn't format floppies (although I'm sure customer complaints added to it), so the operating systems (and maybe the BIOS, you could be right about the 100A) were updated to allow it.

 

[Sharkonwheels]

My standard imaging machine is a Pentium 75mHz, and before was a 90mHz (dropped to 75 for improved compatibility with a CompatiCard IV).

Can you define "I haven't been able to get Teledisk to work on any computer faster than a 486SX/25."? I haven't had any issues, up to even p2's and p3's. Make sure you get a complete version, not just an .EXE, so you can run TDCONFIG to configure it for your particular FDD configuration.

EDIT: Let me clarify that. CC-IV does not work with the built-in BIOS at speeds over 75mHz, according to alot of online sources, and also in some tech docs available online. I had the same issue, and had to drop to 75mHz to get the boot ROM to function correctly. I could've used the CC4DRV.SYS device driver (and do use it for 8" disks) but as I wanted this as the ONLY FDC on the machine, I thought it best to make it work 100% with the CCIV.

T

 

[Micom 2000]

What versons of Teledisk are we talking about here ? I got my first version back around the late 80s, early 90s. It had a disclaimer in it that it wasn't supposed to be used for illegal bbs transfers, but was free-ware.

Teledisk someplace in the late 90s or early 2k metamorphized into a program which was restricted only to government agencies, unless I misunderstood anectdotal postings.

Lawrence

 

[Sharkonwheels]

There's versions out there ranging from about 2.10, to 2.16 or so.
Some are more favorable to 8" - others are less, which is the only reason I have multiple versions.

I normally use 2.14 or 2.15 i think - get a copy with the TDCONFIG though, which configures the TELEDISK.EXE for your particular FDD setup.

T

 

[PrintStar]

My standard imaging machine is a Pentium 75mHz, and before was a 90mHz (dropped to 75 for improved compatibility with a CompatiCard IV).

Can you define "I haven't been able to get Teledisk to work on any computer faster than a 486SX/25."? I haven't had any issues, up to even p2's and p3's. Make sure you get a complete version, not just an .EXE, so you can run TDCONFIG to configure it for your particular FDD configuration.

I guess you're lucky if you have it working. The slowest IBM PC I have lying around is a Pentium 166Mhz, and I'm using the onboard, integrated floppy controller (I don't have a CompatiCard). I've configured Teledisk properly using TDCONFIG and all that. The program runs, it just doesn't successfully write the disk. It usually gets to the point where it attempts to, if I'm remembering correctly.

My statement, "I haven't been able to get Teledisk to work on any computer faster than a 486SX/25," means exactly what it says. The last computer I successfully ran Teledisk on was a 486SX/25 sometime in the mid-nineties. I haven't had that class of PC since, and all other attempts I have made on faster hardware have been unsuccessful. I'm certainly not the only one who has had problems with Teledisk on fast hardware:

Sample 1
Sample 2
Sample 3

Just do a google groups search for "teledisk problems." The number of threads is considerable. Moral of the story is that proprietary disk image formats are a terrible idea, and Teledisk is an old, clunky program that probably should no longer be used.