[N8VEM: 19427] Problem with n8vem v2 board going into HALT state

[Thomas Lienhard]

Hi,

I've built a PPIDE interface for my n8vem v2 board on vero-board because the n8vem isn't really helpful without a mass storage device. I've built a new ROM using RomWBW 2.7 and included the ppide driver. Actually it works. I can copy files to c: and d: (both seems to be 8MB). I have copied some files (Turbo Pascal 3.0 for CPM-80) via xmodem to c: drive. It works so far. But after I exit a program and start it again, the n8vem goes into HALT state and needs to be reset. I also tried other programs (like mbasic from drive b: - rom drive). I can start the basic program with "b:mbasic test1.bas" and it works. Then I enter "system" to leave back to CP/M. Then I start another basic program with "b:mbasic test2.bas" and the n8vem goes into HALT state.

If anyone has an idea, what I do wrong or what's going wrong here, please let me know.

Thomas, hb9evf

[t***@gmail.com]

Hi,

I've built a PPIDE interface for my n8vem v2 board on vero-board because
the n8vem isn't really helpful without a mass storage device. I've built a
new ROM using RomWBW 2.7 and included the ppide driver. Actually it works.
I can copy files to c: and d: (both seems to be 8MB). I have copied some
files (Turbo Pascal 3.0 for CPM-80) via xmodem to c: drive. It works so
far. But after I exit a program and start it again, the n8vem goes into
HALT state and needs to be reset. I also tried other programs (like mbasic
from drive b: - rom drive). I can start the basic program with "b:mbasic
test1.bas" and it works. Then I enter "system" to leave back to CP/M. Then
I start another basic program with "b:mbasic test2.bas" and the n8vem goes
into HALT state.

If anyone has an idea, what I do wrong or what's going wrong here, please
let me know.
Thomas, hb9evf

[Thomas Lienhard]

Hi,

I've built a PPIDE interface for my n8vem v2 board on vero-board because the n8vem isn't really helpful without a mass storage device. I've built a new ROM using RomWBW 2.7 and included the ppide driver. Actually it works. I can copy files to c: and d: (both seems to be 8MB). I have copied some files (Turbo Pascal 3.0 for CPM-80) via xmodem to c: drive. It works so far. But after I exit a program and start it again, the n8vem goes into HALT state and needs to be reset. I also tried other programs (like mbasic from drive b: - rom drive). I can start the basic program with "b:mbasic test1.bas" and it works. Then I enter "system" to leave back to CP/M. Then I start another basic program with "b:mbasic test2.bas" and the n8vem goes into HALT state.

If anyone has an idea, what I do wrong or what's going wrong here, please let me know.

Thomas, hb9evf

[Thomas Lienhard]

Hi, I’ve found something new:

As far as I can see, this only happens when in CP/M, but not in ZSYS. In ZSYS, it seems to work without troubles. But in CP/M mode, it crashes right after the second program start. The LED show’s the HALT state.

Thomas, hb9evf

Von: ***@googlegroups.com [mailto:***@googlegroups.com] Im Auftrag von Thomas Lienhard
Gesendet: Freitag, 3. April 2015 21:46
An: ***@googlegroups.com
Betreff: [N8VEM: 19427] Problem with n8vem v2 board going into HALT state

Hi,

I've built a PPIDE interface for my n8vem v2 board on vero-board because the n8vem isn't really helpful without a mass storage device. I've built a new ROM using RomWBW 2.7 and included the ppide driver. Actually it works. I can copy files to c: and d: (both seems to be 8MB). I have copied some files (Turbo Pascal 3.0 for CPM-80) via xmodem to c: drive. It works so far. But after I exit a program and start it again, the n8vem goes into HALT state and needs to be reset. I also tried other programs (like mbasic from drive b: - rom drive). I can start the basic program with "b:mbasic test1.bas" and it works. Then I enter "system" to leave back to CP/M. Then I start another basic program with "b:mbasic test2.bas" and the n8vem goes into HALT state.

If anyone has an idea, what I do wrong or what's going wrong here, please let me know.

Thomas, hb9evf

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[Wayne Warthen]

Hi Thomas,

Definitely a software problem. I can recreate this problem even using the
SIMH simulator.

Odd that it only occurs with CP/M and not ZSystem.

Anyway, give me a little time to track this down.

Thanks,

Wayne

Post by Thomas Lienhard
As far as I can see, this only happens when in CP/M, but not in ZSYS. In
ZSYS, it seems to work without troubles. But in CP/M mode, it crashes right
after the second program start. The LED show’s the HALT state.
Thomas, hb9evf
<javascript:>] *Im Auftrag von *Thomas Lienhard
*Gesendet:* Freitag, 3. April 2015 21:46
*Betreff:* [N8VEM: 19427] Problem with n8vem v2 board going into HALT
state
Hi,
I've built a PPIDE interface for my n8vem v2 board on vero-board because
the n8vem isn't really helpful without a mass storage device. I've built a
new ROM using RomWBW 2.7 and included the ppide driver. Actually it works.
I can copy files to c: and d: (both seems to be 8MB). I have copied some
files (Turbo Pascal 3.0 for CPM-80) via xmodem to c: drive. It works so
far. But after I exit a program and start it again, the n8vem goes into
HALT state and needs to be reset. I also tried other programs (like mbasic
from drive b: - rom drive). I can start the basic program with "b:mbasic
test1.bas" and it works. Then I enter "system" to leave back to CP/M. Then
I start another basic program with "b:mbasic test2.bas" and the n8vem goes
into HALT state.
If anyone has an idea, what I do wrong or what's going wrong here, please let me know.
Thomas, hb9evf
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[Wayne Warthen]

Hi Thomas,

So, it turns out that MBASIC is writing to the first couple bytes of the
BDOS area. This area of BDOS is supposed to hold the CP/M serial number.
So, what is happening is that when MBASIC is run the first time, it
overwrites the serial number. When you subsequently try to run any
non-transient command, the serial number check in CCP fails and
intentionally halts your system. I have confirmed that running MBASIC on
other CP/M installations causes the same modification of the BDOS memory,
so this is not related to any of my code.

ZSystem is not affected because it has no serial number checking.

The good news here is that there is nothing functionally wrong with the
software or your hardware. The bad news is that I am conflicted about what
to do about this. It would be really simple to remove the serial number
check in CCP. However, my philosophy has always been to keep my
adaptations completely "clean". I will noodle on this a bit, but will
probably end up compromising my philosophies and remove the serial number
check.

I guess a better question is why MBASIC is doing this. Bug? Seems like
this would affect all legitimate CP/M installations. Below is the startup
banner from the MBASIC I include with RomWBW. It is the most recent
version that I have seen. Anyone have any insight?

Thanks,

Wayne

*BASIC-80 Rev. 5.21*
*[CP/M Version]*
*Copyright 1977-1981 (C) by Microsoft*
*Created: 28-Jul-81*
*29752 Bytes free*
*Ok*

Post by Wayne Warthen
Hi Thomas,
Definitely a software problem. I can recreate this problem even using the
SIMH simulator.
Odd that it only occurs with CP/M and not ZSystem.
Anyway, give me a little time to track this down.
Thanks,
Wayne

Post by Thomas Lienhard
As far as I can see, this only happens when in CP/M, but not in ZSYS. In
ZSYS, it seems to work without troubles. But in CP/M mode, it crashes right
after the second program start. The LED show’s the HALT state.
Thomas, hb9evf
Auftrag von *Thomas Lienhard
*Gesendet:* Freitag, 3. April 2015 21:46
*Betreff:* [N8VEM: 19427] Problem with n8vem v2 board going into HALT
state
Hi,
I've built a PPIDE interface for my n8vem v2 board on vero-board because
the n8vem isn't really helpful without a mass storage device. I've built a
new ROM using RomWBW 2.7 and included the ppide driver. Actually it works.
I can copy files to c: and d: (both seems to be 8MB). I have copied some
files (Turbo Pascal 3.0 for CPM-80) via xmodem to c: drive. It works so
far. But after I exit a program and start it again, the n8vem goes into
HALT state and needs to be reset. I also tried other programs (like mbasic
from drive b: - rom drive). I can start the basic program with "b:mbasic
test1.bas" and it works. Then I enter "system" to leave back to CP/M. Then
I start another basic program with "b:mbasic test2.bas" and the n8vem goes
into HALT state.
If anyone has an idea, what I do wrong or what's going wrong here, please let me know.
Thomas, hb9evf
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[Thomas Lienhard]

Hi Wayne,

That’s odd, because it’s not only MBASIC that show’s this behaviour. I can also reproduce it with TURBO.COM and TINST.COM (Turbo Pascal 3.01A) but also with some oft he tools that are on Drive B: (Rom Drive) like UNZIP.COM and SETTERM.COM (and probably more).

Thomas

Von: Wayne Warthen [mailto:***@gmail.com]
Gesendet: Sonntag, 5. April 2015 22:52
An: ***@googlegroups.com
Cc: Thomas Lienhard
Betreff: Re: Problem with n8vem v2 board going into HALT state

Hi Thomas,

So, it turns out that MBASIC is writing to the first couple bytes of the BDOS area. This area of BDOS is supposed to hold the CP/M serial number. So, what is happening is that when MBASIC is run the first time, it overwrites the serial number. When you subsequently try to run any non-transient command, the serial number check in CCP fails and intentionally halts your system. I have confirmed that running MBASIC on other CP/M installations causes the same modification of the BDOS memory, so this is not related to any of my code.

ZSystem is not affected because it has no serial number checking.

The good news here is that there is nothing functionally wrong with the software or your hardware. The bad news is that I am conflicted about what to do about this. It would be really simple to remove the serial number check in CCP. However, my philosophy has always been to keep my adaptations completely "clean". I will noodle on this a bit, but will probably end up compromising my philosophies and remove the serial number check.

I guess a better question is why MBASIC is doing this. Bug? Seems like this would affect all legitimate CP/M installations. Below is the startup banner from the MBASIC I include with RomWBW. It is the most recent version that I have seen. Anyone have any insight?

Thanks,

Wayne

BASIC-80 Rev. 5.21
[CP/M Version]
Copyright 1977-1981 (C) by Microsoft
Created: 28-Jul-81
29752 Bytes free
Ok



On Sunday, April 5, 2015 at 7:44:45 AM UTC-7, Wayne Warthen wrote:
Hi Thomas,

Definitely a software problem. I can recreate this problem even using the SIMH simulator.

Odd that it only occurs with CP/M and not ZSystem.

Anyway, give me a little time to track this down.

Thanks,

Wayne

On Saturday, April 4, 2015 at 7:37:59 AM UTC-7, Thomas Lienhard wrote:
Hi, I’ve found something new:

As far as I can see, this only happens when in CP/M, but not in ZSYS. In ZSYS, it seems to work without troubles. But in CP/M mode, it crashes right after the second program start. The LED show’s the HALT state.

Thomas, hb9evf

Von: ***@googlegroups.com<mailto:***@googlegroups.com> [mailto:***@googlegroups.com] Im Auftrag von Thomas Lienhard
Gesendet: Freitag, 3. April 2015 21:46
An: ***@googlegroups.com<mailto:***@googlegroups.com>
Betreff: [N8VEM: 19427] Problem with n8vem v2 board going into HALT state

Hi,

I've built a PPIDE interface for my n8vem v2 board on vero-board because the n8vem isn't really helpful without a mass storage device. I've built a new ROM using RomWBW 2.7 and included the ppide driver. Actually it works. I can copy files to c: and d: (both seems to be 8MB). I have copied some files (Turbo Pascal 3.0 for CPM-80) via xmodem to c: drive. It works so far. But after I exit a program and start it again, the n8vem goes into HALT state and needs to be reset. I also tried other programs (like mbasic from drive b: - rom drive). I can start the basic program with "b:mbasic test1.bas" and it works. Then I enter "system" to leave back to CP/M. Then I start another basic program with "b:mbasic test2.bas" and the n8vem goes into HALT state.

If anyone has an idea, what I do wrong or what's going wrong here, please let me know.

Thomas, hb9evf

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[Wayne Warthen]

I have confirmed that these apps are definitely doing the same thing.
Apparently, some apps intentionally use the BDOS serial number area for 6
bytes of storage. I don't know why they would want to do this.

After a little more research, it seems that the original behavior defined
by DRI on a warm start is to reload both the CCP and BDOS. If both are
reloaded on a warm start, the halt problem will not occur because both
serial number locations (CCP and BDOS) will be restored to their original
state. However, the newer CP/M variations (like ZSystem) recommend that
you only reload the CCP at warm start so that they can achieve enhanced
functionality like automatic disk relogging. For this reason, I have only
been reloading the CCP at warm start and thus the halt problem occurs.

So, I think I am going to pursue a compromise solution. At warm start, I
will reload CCP and I will restore just the serial number bytes of the
BDOS. This way, there is no change to the authentic DRI code (CCP or BDOS)
and I can still avoid the serial number verification halt problem.

I will try this and post an update in the next day or two.

Thanks,

Wayne

Post by Thomas Lienhard
Hi Wayne,
That’s odd, because it’s not only MBASIC that show’s this behaviour. I can
also reproduce it with TURBO.COM and TINST.COM (Turbo Pascal 3.01A) but
also with some oft he tools that are on Drive B: (Rom Drive) like
UNZIP.COM and SETTERM.COM (and probably more).
Thomas
*Gesendet:* Sonntag, 5. April 2015 22:52
*Cc:* Thomas Lienhard
*Betreff:* Re: Problem with n8vem v2 board going into HALT state
Hi Thomas,
So, it turns out that MBASIC is writing to the first couple bytes of the
BDOS area. This area of BDOS is supposed to hold the CP/M serial number.
So, what is happening is that when MBASIC is run the first time, it
overwrites the serial number. When you subsequently try to run any
non-transient command, the serial number check in CCP fails and
intentionally halts your system. I have confirmed that running MBASIC on
other CP/M installations causes the same modification of the BDOS memory,
so this is not related to any of my code.
ZSystem is not affected because it has no serial number checking.
The good news here is that there is nothing functionally wrong with the
software or your hardware. The bad news is that I am conflicted about what
to do about this. It would be really simple to remove the serial number
check in CCP. However, my philosophy has always been to keep my
adaptations completely "clean". I will noodle on this a bit, but will
probably end up compromising my philosophies and remove the serial number
check.
I guess a better question is why MBASIC is doing this. Bug? Seems like
this would affect all legitimate CP/M installations. Below is the startup
banner from the MBASIC I include with RomWBW. It is the most recent
version that I have seen. Anyone have any insight?
Thanks,
Wayne
*BASIC-80 Rev. 5.21*
*[CP/M Version]*
*Copyright 1977-1981 (C) by Microsoft*
*Created: 28-Jul-81*
*29752 Bytes free*
*Ok*
Hi Thomas,
Definitely a software problem. I can recreate this problem even using the SIMH simulator.
Odd that it only occurs with CP/M and not ZSystem.
Anyway, give me a little time to track this down.
Thanks,
Wayne
As far as I can see, this only happens when in CP/M, but not in ZSYS. In
ZSYS, it seems to work without troubles. But in CP/M mode, it crashes right
after the second program start. The LED show’s the HALT state.
Thomas, hb9evf
von *Thomas Lienhard
*Gesendet:* Freitag, 3. April 2015 21:46
*Betreff:* [N8VEM: 19427] Problem with n8vem v2 board going into HALT
state
Hi,
I've built a PPIDE interface for my n8vem v2 board on vero-board because
the n8vem isn't really helpful without a mass storage device. I've built a
new ROM using RomWBW 2.7 and included the ppide driver. Actually it works.
I can copy files to c: and d: (both seems to be 8MB). I have copied some
files (Turbo Pascal 3.0 for CPM-80) via xmodem to c: drive. It works so
far. But after I exit a program and start it again, the n8vem goes into
HALT state and needs to be reset. I also tried other programs (like mbasic
from drive b: - rom drive). I can start the basic program with "b:mbasic
test1.bas" and it works. Then I enter "system" to leave back to CP/M. Then
I start another basic program with "b:mbasic test2.bas" and the n8vem goes
into HALT state.
If anyone has an idea, what I do wrong or what's going wrong here, please let me know.
Thomas, hb9evf
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