Some success with system one
billdeg
prompt. I believe my two disk drives are bad, the controller card
seems to be OK. It's a 16FDC
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 (view in fixed-width
font, the C page is X).
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 the B
drive I get an error as follows, (the A is pretty much unresponsive):
Seek tests:
01:error 30
I have been told the error code is a HEX code, but could use more
info. 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. My hypothesis is that this system has two bad drives?
If I replace the drives and the system works, then I will let you know.
r...@speakeasy.net
The meanings of the bits in the error code are:
7 Not ready
6 Write protect*
5 Head loaded*
4 Record not found
3 CRC error
2 Track zero*
1 Index*
0 Busy*
(* is not really an "error")
The "T" RDOS command copies the RDOS image down into low memory, enables high memory, and copies it back where it belongs. An "X" in that case really would be a bad thing (EPROM is out of the memory map). I don't think I see that on my systems. Maybe the en/dis function of the 16FDC EPROM is not working?
Seek testing on an unformatted diskette will fail. Are you sure that the diskette is formatted?
Can you do a "A;;DD"? (selects a: as a DD drive).
If so,then try "S 0" (seeks track zero)
Then try "RD 0100 0400 1" (reads enough data, starting at sector 1, to fill 0100-0400 in memory")
A healthy system will do these things just fine (assuming that the diskette is CDOS formatted). They *ought* to be non-destructive of what's on the diskette.
Hope this helps.
Roger
billdeg
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
MikeS
On Apr 5, 11:55 pm, billdeg <bill...@aol.com> wrote:
> Thanks. 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. seehttp://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
The picture's unclear, but the 16FDC switch settings look wrong; they
should be set as per the manual: 2 and 3 on, 8 off.
The RTC jumper is normally installed.
The drive jumpers look fine (assuming a straight (not twisted) cable).
The terminator should be on whichever drive is farthest from the
controller.
bil...@aol.com
Bill
bil...@aol.com
I had been working with the 4FDC manual from my other system, but these pictures were taken in 2006? (despite the fle date) , and are the original switches as the system came to me from the seller. The system was un-cabled and obviously tampered with. This helps, I did not have 2 and 3 on.
http://www.vintagecomputer.net/cromemco/system_one/16FDC.jpg
(pic of how I got the card originally)
rather than doing the responsible thing like getting ready for work, I am going to try it now...
Bill
billdeg
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?