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Looking for 8" floppies with CP/M 2.2 for Altair with Tarbell controller

E

Equalizer700

Member
Joined
Oct 23, 2008
Messages
12
I'm resurrecting my 1975 hand-built Altair. I'm looking for 8" floppies with CP/M 2.2 for an Altair with Tarbell controller and DualStor disk drives. Any leads will be greatly appreciated.

I also would like some advice on resurrecting some cassette tapes with Basic and ASM on them...I have an 88-ACR and the tape drive, but the tapes are so old I'm afraid to load them unless I am sure what I'm doing. Is there any PC software that will find and/or restore any dropped bits?

Does anyone know the format of the DualStor disks? SS or DS? SD or DD? Hard or soft sectored?

Any help or advice is welcome!

John
 
I probably have the boot floppy that I used with my Altair with the original Tarbell controller and MITS SIO card. No guarantees, but if it's still readable, I could send you a BIOS listing to peruse. Drop me a PM if you're interested.
 
Sorry to disappear, but I'm back

Sorry to disappear, but I'm back

Bill and Chuck,

Sorry to have dropped out of sight for a month or two. Had to spend some time in the hospital but now everything is ok.

Bill, I have put high resolution pics of the Tarbell controller at www.speedreferrals.com/pic1.jpg through pic 4.jpg. As you'll see there are lots of jumpers on the back side (as with lots of things of that era). It looks like the board might have been jumpered to be a Rev B, since there is a B scratched on the back side. If you would like a better pic of an area of the board I will be happy to get it for you. There are no jumpers on the component side, just a dip switch.

Chuck, I appreciate the offer of a BIOS listing, but I don't know how to get from that to a bootable floppy. Do you know anyone who has the facilities to copy a disk? I have read that there are ways to read and write 8" floppies using a PC floppy interface cable and an adapter of some sort. Do you know who the experts are on this subject?

I really appreciate your help!

John
 
Equalizer700 said:
Chuck, I appreciate the offer of a BIOS listing, but I don't know how to get from that to a bootable floppy. Do you know anyone who has the facilities to copy a disk? I have read that there are ways to read and write 8" floppies using a PC floppy interface cable and an adapter of some sort. Do you know who the experts are on this subject?
Click to expand...

Yes, you can make an adapter (or just get one from DBit Probably not a bad thing to have around in any case...

But, the Tarbell (mine looks just like Bill's) controller uses a WD1771 single-density controller, so your PC has to be capable of supporting FM recording mode. Not all are.

Fortunately, there's an easy way to separate the wheat from the chaff. Attached is a DOS executable called TESTSD.EXE. It attempts to format and read track 74 on the first 1.44MB 3.5" drive on your PC. Just boot DOS (can even reside on the test diskette), run TESTSD and look at the output.

I can supply an image in many formats; Dave Dunfield has written Image Disk which is a good one, but I can also supply TeleDisk images or any other format you'd care for.

I also have the manual for the Tarbell controller, if it's not online. Configuring those jumpers for your drives can get to be a head-scratcher without a guide.
 

Attachments

  • testsd.zip
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Getting a floppy...

Getting a floppy...

Bill,
Chuck,

Wow, thanks for the info! I have looked on all sorts of other boards and haven't found anyone else who even knows what I was talking about.

Believe it or not, my current PC doesn't even have a floppy drive...just the cable. I ordered a drive from Newegg and will run the test Chuck sent when I get it. I also have some other, older PCs lying around...I'm sure one of them will work.

I'll start saving my allowance for a dbit adapter, too.

I'll let you know the results...

Thanks again!

John
 
Hi John,

How is your Altair Tarbell project going? I'm resurrecting my Altair/Tarbell/Vector Graphic project and have some questions:

What model of Altair do you have and what boards are in it? I'm especially interested in how much RAM amd which IO board.

You mention DualStor disk drives. Are these Vector-Graphic disk drives? If so, are they the original Dual-Stor or the newer Dual-Stor?

The following page has Dual-Stor pictures for reference:

http://vector-graphic.info/vg_dual_stor.aspx


Tom
www.virtualaltair.com
www.vector-graphic.info
 
Hey hey hey. If and when I get my 8" drives working, that Dbit thing sounds like just the ticket. Guess I'll have to run around and test with your SD test deal too. I wasn't having much luck finding a CP/M that was preconfigured for the Tarbell. Looks like take a closer look at the drives is the first order of biz.
 
You can always run an emulator under DOS/Windoze to build your binaries and then use something like 22Disk to write the boot tracks to an 8" drive.

Are you still interested in a source code for a BIOS using the Tarbell?

Depending on your 8" drive (whether or not it needs TG43/RWC), you might be able to get away without the dbit thing and just build your own PC-to-8" cable. It's not hard.
 
Yes on the source code. chuckcmagee at msn dot com.

For $40 + shipping, I would much rather have a nice pretty neat Dbit sitting here instead of a hack sawed edge connector off a floppy drive, with a bunch of somewhat well soldered too large wires running all over the place.

I do own one of those fancy Wellers but I got it off of ebay. Most of the time, seems like it doesn't get hot enough --- Now we know why it was on ebay.
 
Hi Tom,

I have the original DualStor drives...the green/white one with the two drives together as one unit. I also have a Peripheral Vision dual drive cabinet with only one drive. As I remember it, I was one of the first people do have a floppy on the Altair, so it is all early stuff.

As for memory configuration, as the box was when I got it our of storage it had a Memory Merchant 16K board, a MITS 4K board and a Seattle Computer Products 16K board in the chassis. I also have some loose 4, 8 and 16K boards from other manufacturers.

It has a 2SIO IO board and a EProm board with the boot loader. I also have the Eprom for loading from cassette.

Do you know if the DualStor has SS/SD drives?

As for the Altair project, I'm not having much time to work on it between regular work and digging my driveway out of all the snow. But today it is warming up and starting to melt and the at work project should finish this week...so I hope to get back to it soon.

Would you (or anyone?) be willing to split the cost of the Dbit adapter and share it's use? Or maybe we can make disks for each other? Surely someone has already done this and can make disks at will?

John
 
You know that you don't have to hack into cables.

Just get a small hunk of perf board, install two headers on it--one 50-pin, the other 34-pin and wire the two up. Since half the connections are grounds, it shouldn't take you long. Plug a 50-pin female to 50-pin edge cable onto one header and your 8" drive and a standard 34-conductor floppy cable on the other.

Microsolutions used to sell a setup very like this, except said board was a small PCB.

Or make your own DBIT thingie. You could do it with an 8-pin PIC; you need only sample TK00 from the drive and STEP and DIR and DSEL from the controller--assert RWC/TG43 when you determine that the drive's in the right place. Assemble it on some perfboard.

Easily only an afternoon's worth of work.
 
Chuck(G) said:
You know that you don't have to hack into cables.

Just get a small hunk of perf board, install two headers on it--one 50-pin, the other 34-pin and wire the two up. Since half the connections are grounds, it shouldn't take you long. Plug a 50-pin female to 50-pin edge cable onto one header and your 8" drive and a standard 34-conductor floppy cable on the other.

Microsolutions used to sell a setup very like this, except said board was a small PCB.

Or make your own DBIT thingie. You could do it with an 8-pin PIC; you need only sample TK00 from the drive and STEP and DIR and DSEL from the controller--assert RWC/TG43 when you determine that the drive's in the right place. Assemble it on some perfboard.

Easily only an afternoon's worth of work.
Click to expand...

Mine is from CDR Systems, P/N 85002. It even has jumpers to ground out pin #34 of the 50-pin and #2 on the 34-pin side if necessary. It came as a bare PCB, I had to pop the headers myself, but it's a very simple setup and could be easily copied on perfboard.

--T
 
> “… maybe we can make disks for each other? Surely someone has already done this and can make disks at will?”

The Tarbell has been interfaced to an Altair many times. There are multiple threads with requests for help, however, I haven’t found a complete documented solution. Hopefully, more people will help, however, Altair owner may be very busy or the Altair system is in storage or no longer working. My goal is to document a solution and make a supply of boot disks and/or boot images available.

> “I have the original DualStor drives...the green/white one with the two drives together as one unit.”

Can you provide an image for my Dual Stor page? http://vector-graphic.info/vg_dual_stor.aspx
Does your Dual Stor have a stand-alone power supply or use a regulator board and power from the mainframe?

> “Do you know if the DualStor has SS/SD drives?”

The 1977 VG catalog says the Dual Stor disk system has a capacity of 243K bytes and uses the standard IBM compatible format. That indicates that the drive is SSSD. It would be good to know the drive manufacturer and model. Drive specific jumper settings may be required for the drive or Tarbell. I’d also like to compare the jumper settings on your Tarbell 1011A to the D revision.

I’m documenting the configuration for a Tarbell 1011D, Shugart SA 801, Pertec FD 514, and later Qume DT/8 on my page http://vector-graphic.info/vg_tarbell_1011d.aspx. The Tarbell manual documents the configuration for several other drives

> “It has a 2SIO IO board and a EProm board with the boot loader”

Good, the Altair 88-2SIO is probably what most people have in an Altair. http://www.virtualaltair.com/virtualaltair.com/vac_88-2SIO.ASP
I also plan to document the Intel 8251A implementation for Vector Graphic computers.

I assume you have a front-panel Altair. I’m using turnkey computers and require a separate boot loader prom. That requires Tarbell switch 1-7 to be off to disable the Tarbell 82S123 Bootstrap prom.

> “As for memory configuration, ….”

I asked about memory configuration, since any boot disks provided must be configured for available memory. A 64K CP/M boot disk for an 8800b Turnkey won’t be useful to many people. A 48K CP/M will work on a 56K Vector Graphic. A 32K CP/M will be handy for people with a shortage of memory boards.

> “Would you (or anyone?) be willing to split the cost of the Dbit adapter and share it's use? “

I’m saving my pennies for a Dbit, but first must find spare time and get my drives up and running. I’ll try my Compaticard first, but would like to document use of the Dbit and the software required to make Tarbell boot disks on a PC. I have Uniform PC, but don’t know anything about 22Disk. Will we end up copying a 8-inch disk, or need to assemble BIOIS ASM using an emulator?

You may want to take a look at the Altair Peripheral Emulator (APE) for a quick way to use CP/M on an Altair. This tool is still useful with a Tarbell. You can find it in the reference links I’m adding below.

Related Links

Looking for Tarbell CP/M Boot Disks (altaircomputerclub message 1413)
http://groups.yahoo.com/group/altaircomputerclub/message/1413

Tarbell is making me insane. From: Grant Stockly
Classic Computing Mailing List Archive
http://archive.netbsd.se/?ml=cctech&a=2007-11&m=5623418

FDADAP floppy disk adapter.
http://www.dbit.com/fdadap.html

"The D Bit FDADAP board is a small adapter which adapts 8" floppy disk drives (Shugart SA800 style bus) to work with the PC 3.5"/5.25" floppy disk cable pinout"

APE - To mimic: The Altair Peripheral Emulator
http://frankbarberis.tech.officelive.com/default.aspx

"The Altair Peripheral Emulator is a program that allows a Windows PC to emulate up to four floppy disk drives for an Altair 8800 series computer"


Tom Sanderson
www.virtualaltair.com
www.vector-graphic.info
 
Equalizer700 said:
Hi Tom,

I have the original DualStor drives...the green/white one with the two drives together as one unit. I also have a Peripheral Vision dual drive cabinet with only one drive. As I remember it, I was one of the first people do have a floppy on the Altair, so it is all early stuff.

As for memory configuration, as the box was when I got it our of storage it had a Memory Merchant 16K board, a MITS 4K board and a Seattle Computer Products 16K board in the chassis. I also have some loose 4, 8 and 16K boards from other manufacturers.

It has a 2SIO IO board and a EProm board with the boot loader. I also have the Eprom for loading from cassette.

Do you know if the DualStor has SS/SD drives?

As for the Altair project, I'm not having much time to work on it between regular work and digging my driveway out of all the snow. But today it is warming up and starting to melt and the at work project should finish this week...so I hope to get back to it soon.

Would you (or anyone?) be willing to split the cost of the Dbit adapter and share it's use? Or maybe we can make disks for each other? Surely someone has already done this and can make disks at will?

John
Click to expand...

I’m like you, I have limited time to work on this project. It's been 30 years since I solved this problem and I am slowly remembering and researching the details. I looked a Chuck's BIOS and remembered that some people had a monitor prom and used it for console IO. You didn’t mention a monitor prom, but did mention a boot loader prom. Did you have the DualStor working with your Tarbell in the past? If so, I can assume your controller and drives have the proper jumper setup.

I have two BIOS versions. The Vector Graphic BIOS version used a monitor prom and the Altair version has BIOS code for the Altair 88-2SIO. I have my original hardware, but it didn't boot when I tried it a few years ago. There are several people that have used a Tarbell with an Altair. I don't know how many still have their system up and running.

My boot and BIOS code is on 8-inch disks and I want to make it available, but first I need to get some 8-inch drives working. I see from reading the replies to your first message, that one approach is to interface 8-inch drives to a PC. That approach will be useful to get my code, but will require me to set up tools on the PC to assemble the BIOS code. There are several parts to this problem: 1) Find time for the project; 2) Get the hardware working; 3) Interface drives to the Tarbell; 4) Interface drives to a PC; 5) Set up development software; and 6) Assemble a boot disk.

Hopefully, your drives and Tarbell are in good shape. I have to put my drive system back together as a first step. If the drives don’t work with my S-100 machines, I’ll try the PC approach to test the drives. I’ll try my Compaticard first and then maybe the Dbit. My original drives are Pertec and require a 10ms step rate. I can set the step rate with the Compaticard, but don’t know how to do that with the Dbit. I have a Shugart SA801 and a pair of Qume DT/8 drives. Both need a power supply and connector.

I hope we can find someone with a working system that can make boot disks. If not, I’ll try to get my S-100 hardware to boot again or at least read my source code disks on a PC. After that, I’ll need to re-learn how to assemble a boot disk. So, assuming your hardware is in good shape, your Tarbell and drives are jumpered correctly, we need a boot disk that initializes a 2SIO and is configured for available memory. What size of CP/M do you need on a boot disk?
 
Progress - Booted CP/M 2.2 with Tarbell and 8-inch drive

Progress - Booted CP/M 2.2 with Tarbell and 8-inch drive

I started with two Tarbell 1011D controllers, two Pertec FD514 drives, and two 8-inch boot disks. If found one of each pair was bad. Using the good components, I was able to boot 56K CP/M 2.2 configured for Vector Graphic IO and monitor prom. My next project is get a second drive working so I can copy diskettes. I’ll also need to get my 8-inch software library out of storage and find some blank diskettes.

At this point, I could move the controller and drive to an Altair and test the 60K Altair boot disks that I found. I’m going to try for a second drive first. I’ll also look for the diskette the with boot prom and BIOS source code. This should be good news for anyone with a 60K Altair, however. I’d like to publish the source code and make some 48K or smaller boot diskettes.

Tom Sanderson
www.virtualaltair.com
www.vector-graphic.info
 
And of course you can often replace the 8" drives with 5 1/4" HD drives; some people swear by TEACs, while Rich Cini (IMSAI/Compupro) and I (Cromemco) have had good luck with YE Data drives. I've also used Panasonics but if there are several drives on the cable it's better to have drives with a head load solenoid. Even if you have an 8" drive it's handy to have a 5 1/4" equivalent as well, for copying/backing up, and restoring images on a PC.
 
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