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Looking for Cromemco RDOS Disk Test Error code listing

billdeg

billdeg

Technician
Joined
Nov 18, 2003
Messages
3,885
Location
Landenberg, PA USA
I am looking for RDOS Disk Test Error code listing.

The other thread about the FDC for the Cromemco got me thinking it was time to try my System One again, I had not been able to get it to output to a terminal, but I had not tried since 2008, according to my notes.

Long story short, now I can boot my Cromemco System One to RDOS 2.52, using a 16FDC.

Taking it further....A thought-to-be working system diskette does not boot in this system on either drive. I suspect two bad disk drives, but I can't prove it yet. But at least I have a RDOS prompt finally.

Sometimes the message "stand by" comes up and the system hangs

Sometimes it makes it to this error:

Unable to boot
0001-0
Err-B 34

RDOS 2.52 has a test program that is activated with the command "T"

1) The memory test returns an "X" on the C page.
0 1 2 3 4 5 6 7 8 9 A B C D E F
^ ^ ^ ^ ^ ^ ^ ^ ^ ^ x ^ ^ ^

The manual says an "X" is bad, but isn't this where RDOS is located? I can see the code is there, so I am not sure how to interpret the X vs. the ^. I have two 64K Cromemco memory cards, same results.

2) The test program continues and when I run a disk test on either A or B drive I get an error as follows, so I am looking for the error code list so I can troubleshoot the meaning of the error:

Seek tests:
01:error 30

Fortunately these systems came with Tandon drives so I can try another drive, after testing in an IBM PC to be sure it works OK first. I guess this system has two bad drives?

If I replace the drives and the system works, then I will let you know.

Bd
 
You can find a listing of the error codes in the *FDC manual. I printed a copy of the 4FDC manual which contains the error codes, but I don't know if they're the same for the 16FDC. I get sensible errors when trying to access a floppy disk in a 5.25" HD drive hooked up to my 4FDC (I didn't expect it to work, being HD, but I confirmed the floppy interface works as I can activate drives based on their drive select ID, and I can step the heads forward and backward).
 
The error codes are indeed defined in the manual, but their meaning depends on the attempted operation. In any case you're obviously getting read errors; does "A thought-to-be working system diskette" mean that you only have one, and you're not even sure that it's readable? A bad diskette is what I usually suspect first, especially if it can't be read in two different drives; have you tried reading it in a PC with something like Dave D's IMD, preferably using the actual Cromemco TM100s? The first track/side might show an error, but the rest should read fine if the disk is OK.
 
Bill,

Hi there. First you could copy this to the Cromemco Forum ... http://groups.google.co.uk/group/cromemco?lnk=srg&hl=en

And now to ponder your question ...

All my RDOS manuals are online here http://maben.homeip.net/static/S100/cromemco/RDOS/index.html
They help a little but I have never seen an uptodate RDOS manual.

I think the error message Err-B 34
mean

Boot error with hex code 34
Hex 34 turns into


BIT 7 6 5 4 3 2 1
0 1 1 0 1 0 0

So if you look in the manual Cromemco RDOS Instruction Manual 023-0052 197901
Write Protect Head Engaged and CRC error


Memory Error:
The RDOS ROM was at 0xc000 from memory and surely the code relocates itself during the memory test?

The way I think it is supposed to work is that on poweron the processor should jump to 0xC000 where it should find an enabled RDOS rom. This also means that the initial config of your 64K memory
card has this area as temporarily disabled.

Then when you execute the T command RDOS copies away the RDOS code, enables the RAM memory, puts back the RDOS ROM code back into RAM and then tests all memory locations.
At least that what I had always assumed it was doing!

So apart from getting some more copied of CDOS, and floppy drives I'd check the settings on the RAM card to be sure it is bank selecting correctly.

(My online copies of the 64KZ and 64KZ II manuals are here of course http://maben.homeip.net/static/S100/cromemco/cards/index.html )


regards marcus b.
 
Marcus,
I believe I am using the 5 1/4" disk you mailed me about a year ago to test my System Three (thanks again)....I will post to your forum, I was trying to find it yesterday in Yahoogroups by accident. I did visit your web site to see if there were any other docs I needed.

It is also possible that "34" corresponds to track 34?

How would you interpret the error I reported above? The manual that I have is unclear, I do have a printed copy of both the 4FDC and 16FDC.

What I think the next step is to check out the jumpers on the Tandon drives, and try another set of drives after matching the settings.

The drives did not "sound right" for Tandons. One seems worse than the other.

From the RDOS 2.52 prompt I used "BB" to boot from drive B, and "B" to boot from the default (A).

For the benefit of people reading this post in the future, "BB" is not recognized if using a 4FDC.

Bill
 
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Hmmm. I am pretty sure that 34 does not refer to track 34, but is the hex code of the error.

Also BB and BA are correct RDOS boot commands although only CDOS 2.X will boot to the B: drive. CDOS 00.xx and 01.xx will only boot to A:

Meanwhile since I mailed those diskettes to you I have found a fairly reliable way to create Dunfield .IMD diskette images. And so I have spent almost (another) 9 months now .IMD ing my diskette collection.

So if you goto the diskettes section of the cromemco directory i.e. under code

http://maben.homeip.net/static/S100/cromemco/code/index.html i.e. disks and NOT dunfield images directory, then anything *.IMD is a dunfield image.

Look in the catalog.txt file first for relevant CDOS diskettes. http://maben.homeip.net/static/S100/cromemco/code/disks/catalog.txt

Since you have a 16FDC you can try a double density version of CDOS i.e. 2.x since 01.xx did not support Double density (I think?)

Also if it helps I can create any 5.25" CDOS version now and using CDOSGEN.COM build a CDOS with the drives you want ... presumably 2 x 5.25 inch DSDD drives?
and 64KB memory? Let me know. And then upload a custom .IMD image. All this presupposes you have a working PC to create the diskettes from .IMD downloads obviously.

regards mb.
 
[this is a copy of the same post to the Cromemco forum in Google]

I have made more progress.
Definitely both original disk drives are bad. Fortunately I have more
Tandon 100-2a's to try out.

Knowing that the two new test drives were good, I decided to focus on
the 16FDC. I put a 4FDC inits place and I was able to boot from the A
drive finally. I was not able to do anything with the B drive (no dir
for example), I kept getting a Drive not Ready error. When I switch
the drives around and swap the jumpers, I can boot with the formerly B
drive as the A drive, so that tells me that maybe I have a drive board
jumper setting problem. I have swapped numerous drives and the power
connectors to be sure it's not a power problem. View pics of the
original Tandon 100-2a jumper assignments for drive A and Drive B in a
Cromemco System One. The terminator is in drive A. see
http://www.vintagecomputer.net/cromemco/system_one/ for pics.

The 16 FDC, using the same drives that worked with the 4FDC, hangs in
a peculiar way. The drive motor starts out OK, but gets stuck in a
pattern of jumps to the same few tracks over and over, but never
engages past this to boot the OS.

Possible Conclusions
The 16FDC needs some sort of repair. Next - try testing the voltages.
Fortunately I/O works at least.

The 16FDC has a jumper that is not compatible with the drives I am
using? There is a jumper installed and I believe it's the one
described on page 27 of the 16FDC manual. I might try taking this out
to see what happens, or at least learning more about why it's there.

ALSO - play around with the jumper settings used for Drive B. That's
the way the system came to me, but who knows what was done with this
computer before I got to it!

These are well-built machines. You have to disassemble the system
partially to get to the drives, but once you do, you can swap them in
and out easily for testing purposes. I am using a semi-compatible
terminal, but that's a separate issue I can deal with later.
Bill
 
You do have a manual???

Before you start testing voltages and cutting/soldering jumpers, has it occurred to you to check the DIP switch settings, or compare them to the working 4FDC? The picture's not very clear, but they sure don't look right to me; 2 and 3 should probably be on, and 8 off.

You don't say *which* jumper on page 27 is installed; the RTC jumper is normally installed.

And why do you want to "play with" the drive jumpers? One is jumpered for DS0 (drive A), and the other for DS1 (drive B); assuming that you're using a straight cable and not a 'twisted' one, what's wrong with that?

The location of the terminator is probably not important, but it doesn't go on drive A or drive B, but on whichever one is farthest from the controller (i.e. at the end of the cable).

Then we'll see...
 
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Mike I am jumping btwn this and the Cromemco group, to post ... I will try these suggestions, confirm the jumper is RTC, etc.

Bill
 
2 and 3 were off to boot to RDOS without automatically jumping to the OS. I can boot to disk, it's the B drive that reports B drive is "not ready". If the drive jumpers are correct, and the card jumpers are correct, and the "B" drive works as an A drive when I swap them, and I put the terminator at the end of the line, and the voltage is correct leading to the drives, - it must be the 16FDC controller.
 
billdeg said:
2 and 3 were off to boot to RDOS without automatically jumping to the OS. I can boot to disk, it's the B drive that reports B drive is "not ready". If the drive jumpers are correct, and the card jumpers are correct, and the "B" drive works as an A drive when I swap them, and I put the terminator at the end of the line, and the voltage is correct leading to the drives, - it must be the 16FDC controller.
Click to expand...
Now I'm really confused.

You said
I put a 4FDC inits place and I was able to boot from the A drive finally. I was not able to do anything with the B drive (no dir for example), I kept getting a Drive not Ready error. When I switch the drives around and swap the jumpers, I can boot with the formerly B drive as the A drive, so that tells me that maybe I have a drive board jumper setting problem.
Click to expand...
If you're also having this problem with the 4FDC, how does this prove that there's something wrong with the 16FDC? It doesn't matter where the drives are connected, so what happens when you just switch the drive jumpers (without moving the drives)? Sounds like it might also be the cable.

Above you say that "you can boot to disk" but you also said
The 16 FDC, using the same drives that worked with the 4FDC, hangs in a peculiar way. The drive motor starts out OK, but gets stuck in a pattern of jumps to the same few tracks over and over, but never engages past this to boot the OS.
Click to expand...
So which one "boots to disk"?

AFAIK switch 8 ON (as it appears to be) will try to boot from drive B.

Switch 2 being off means that the C block will contain the RDOS ROM instead of RAM; I can't say for sure but this might interfere with booting CDOS.

If you don't want to boot then switch 3 can indeed be off, although pressing ESC will do the same thing.

Good luck!
 
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Sorry about that. My postings are all over the place, sloppy! I am posting to two places at once and I am even confusing myself.

Here is where things stand to clarify.
1. I now have a pdf of the 16fdc and I fully understand the switch settings/jumpers. I also have a 4FDC. I like to boot to RDOS and then run the B command to boot (or the BB command to boot to B when using the 16FDC.)

2. I have two systems that I am using for testing
a. Crom System One (5 1/4" Tandon 100-2a's)
b. Crom System Three (8" Persci 299 dual)

3. I have the correct drive jumpers, I have the correct terminator in place where it should be, as I switch things around.

4. Using the System One, I have two Tandon 100-2a's that will boot CDOS, using either the 4FDC and the 16FDC. If I take the boot disk out of drive A and stick it in drive B, switch to drive B and then run a DIR command I get a "Drive not ready" error for BOTH controller cards (repeating the experiment with either card installed). If I swap drives and repeat the same experiment I get the same result (boot from A, drive B not ready). I have been very careful to make sure I have the correct jumpers and terminator placement.

5. With the 16FDC in the System One I cannot boot to the B drive. The drive seeks up and down the lower tracks and never completes the boot cycle. ( this experiement is repeated with more than one working drive)

makes you think that there is a problem with the controller? But...I am not sure because both the 4FDC and 16FDC have the same exact problem with drive B not being ready.

6. The System Three has a bad A drive (disk detect issue), but the B drive is OK (this is a separate project). Using the 16FDC in the System Three I can boot to the B drive!

At least in the System Three the 16FDC is capable of booting a system to the B drive. The only thing I can think of is that the CPU or memory cards in the System One has issues preventing the drive ready signal from the B drive from being detected.

The next thing I will try is swapping the drive cable, and if that does not fix the problem I will swap the CPU and RAM cards from the System Three and put them into the System One to see if it boots directly to B.

Does that help clarify? ever seen this before?

Bill
 
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Have you checked your floppy cable? If the problem follows the connector, usually that has something to do with it. Also, if the cable is one of the newer "PC" style cables with a twist in the line, that complicates the drive select matter.

You did actually get a 4FDC to boot CDOS off of a Tandon TM-100, correct? In that case, I suspect that the 4FDC will work with any DSDD 5.25" drive, as I can't find any information suggesting the TM-100 had its own data separator. This does make some amount of sense, as the WD1771 does actually have a data separator -- there's a pin that disables it for at least the 8" drives with a 4FDC. Without a schematic for the 4FDC, I can't confirm how it is or isn't set up.
 
Does that help clarify?
Click to expand...
Umm, not really.You only have one system with 5.25" drives, but in step 4 it only boots from drive A with either controller whereas in step 6 it boots from drive B.

Is step 4 actually talking about the System 3 with external 5.25" drives temporarily hanging off the FDC with a separate power supply, or what's this about?

Let's see what happens when you finally check the cable, i.e. leave the drives in place and just move the select jumpers.
 
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glitch said:
Have you checked your floppy cable? If the problem follows the connector, usually that has something to do with it. Also, if the cable is one of the newer "PC" style cables with a twist in the line, that complicates the drive select matter.

You did actually get a 4FDC to boot CDOS off of a Tandon TM-100, correct? In that case, I suspect that the 4FDC will work with any DSDD 5.25" drive, as I can't find any information suggesting the TM-100 had its own data separator. This does make some amount of sense, as the WD1771 does actually have a data separator -- there's a pin that disables it for at least the 8" drives with a 4FDC. Without a schematic for the 4FDC, I can't confirm how it is or isn't set up.
Click to expand...
Yes, that was my thinking, that it sounded like a problem with the cable, and that's why I suggested just moving the jumpers; moving the drives just confuses things.

BTW, I did point you to the 4FDC schematics in the other thread:

http://maben.homeip.net/static/S100/cromemco/schematic/index.html
 
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MikeS said:
Umm, not really.You only have one system with 5.25" drives, but in step 4 it only boots from drive A with either controller whereas in step 6 it boots from drive B.

Is step 4 actually talking about the System 3 with external 5.25" drives temporarily hanging off the FDC with a separate power supply, or what's this about?

Let's see what happens when you finally check the cable, i.e. leave the drives in place and just move the select jumpers.
Click to expand...

Re-read my corrected post. The system three only boots from the B drive.
 
glitch said:
Wow, completely overlooked that...I'll start a new thread concerning drives with the 4FDC after I look it over and try a few things.
Click to expand...
That will be interesting. There are definitely issues with 8" drives, even with the 16FDC and its various revisions, but there seems to be some conflicting info about using various 5.25" drives with the 4FDC.
 
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