Diagnosing Maxtrac RSS on Toshiba T3100e

[K9RPL]

I've been trying to get the Maxtrac RSS R07.02.00 to see the serial ports on a Toshiba T3100e and the RSS just flat refuses to access either Comm Port (1 or 2). The T3100e is a 286 based portable that runs at either 12 or 6MHz. It has the typical serial ports using the normal IRQ's and addresses. I'm using a RIBLess cable form BlueMaX 49'ERS. Anytime I try the comm port test on the RSS, it reports some kind of comm port power fail error. I know the ports work. Even a full CheckIt test says they're fine and that's with a loopback connector.

If I run the very same RSS and cable on my Compaq Portable II (8MHz 286) it works just fine. No issues. I was hoping to move my radio programming software over to the T3100e since it's a bit easier to carry around. Not much lighter, but no where near as bulky as the Portable II.

I'm trying to find the Motorola commchek program and see if it reports anyting, but no luck so far finding it.

Any suggestions?

 

[K9RPL]

As a followup the error I'm seeing when I try the Serial Port test is:

Serial Bus Error:
#5 Power Failure

 

[RBMTS]

Hi Chuck
Some older laptops and PC's had the ability to set serial ports on or off via the PC BIOS. If you haven't yet, access the BIOS on power-up and look for any settings that would control the serial ports. I'll keep my fingers crossed for you.

Randy / N9APP

 

[ElroyJetson]

Old electronics, suspect component value drift or failure. Resistors off spec, capacitors that are leaky or off value or in the case of tantalum capacitors, hard shorted. Absolutely these can cause digital circuits to malfunction and error out.

 

[RFI-EMI-GUY]

When copying RSS without an installer, see if this attributes on any file are archive or read only. some RSS executables need to write to files to work.

 

[gary123]

Also if the computer is too fast then the port timing/communications get messed up.

 

[AM909]

Standard serial port IRQ and address (0x3F8 and IRQ4 for COM1)? Could something already be talking to the port? Can you create and boot from an MSDOS disk to eliminate anything that might be in the machine's OS config?

 

[K9RPL]

Hi Chuck
Some older laptops and PC's had the ability to set serial ports on or off via the PC BIOS. If you haven't yet, access the BIOS on power-up and look for any settings that would control the serial ports. I'll keep my fingers crossed for you.

Randy / N9APP

Hi Randy!

The BIOS does set the ports but I've verified they are correct, IRQ's and Addresses set to the correct defaults. In fact, I loaded up Checkit and ran the in depth diagnostic tests using a loopback from an RS-232 breakout box. All the tests passed with flying colors. I also tried running Procomm Plus talking to a Hayes SmartModem on both ports. No problems.

 

[K9RPL]

Standard serial port IRQ and address (0x3F8 and IRQ4 for COM1)? Could something already be talking to the port? Can you create and boot from an MSDOS disk to eliminate anything that might be in the machine's OS config?

Nothing else talking to the ports. IRQ and Address also correct. This is all straight, plain vanilla MSDOS 6.2.2 booting from a local drive.

 

[K9RPL]

When copying RSS without an installer, see if this attributes on any file are archive or read only. some RSS executables need to write to files to work.

It's actually copied from my Compaq Portable II that runs the software just fine. I just copied the directory to a CF card and plugged it into my T3100e with and XTIDE card.

 

[K9RPL]

Old electronics, suspect component value drift or failure. Resistors off spec, capacitors that are leaky or off value or in the case of tantalum capacitors, hard shorted. Absolutely these can cause digital circuits to malfunction and error out.

I would agree, but I've run some extensive diagnostics on the T3100e with CheckIt. I put a loopback on both serial ports and ran the full serial port diagnostics. It passed with no errors.

 

[K9RPL]

Also if the computer is too fast then the port timing/communications get messed up.

The Toshiba runs at either 12 or 6MHz. I've tried both speeds. The Compaq runs at 8MHz. Both are 80286 CPU's. This version of the RSS takes into account faster machines and doesn't use the old timing loop method (per the release notes).

 

[K9RPL]

When copying RSS without an installer, see if this attributes on any file are archive or read only. some RSS executables need to write to files to work.

Double checked. All are full access.

 

[K9RPL]

I'm really hoping I can track down a copy of the COMMCHK program...

 

[AM909]

Thinking along the lines of what someone said about old hardware and voltages, it could be out of spec enough to not work with an external device but still be able to pass a loopback test to itself, since both would be using the same out-of-spec rails. What are the voltages on DTR (DE-9 pin 4) and DSR (pin 6) relative to ground (pin 5), with nothing attached or running and then with the loopback test?

 

[K9RPL]

I can certainly check that. I will say I have tested with other RS-232 devices like the Wi-FI SmartModem which is a replacement board for the Hayes SmartModems. The T3100e running ProcCommPlus had no issues.

 

[K9RPL]

Thinking along the lines of what someone said about old hardware and voltages, it could be out of spec enough to not work with an external device but still be able to pass a loopback test to itself, since both would be using the same out-of-spec rails. What are the voltages on DTR (DE-9 pin 4) and DSR (pin 6) relative to ground (pin 5), with nothing attached or running and then with the loopback test?

Nothing attached except my IDS Blue Box breakout which has the test points I need.

On nthe T3100e I'm measuring 8.39V on both DTR and RTS.

On the Portable II I'm measuring 10.3V on DTR and RTS.

Could it really be a matter of a 2V difference?

 

[K9RPL]

I got to thinking about this and I think I know what the issue is. I usually use a RIB for most of my older radios. But in this case I bought a RIB-Less. Ok, so why would it fail me?

Well, if the Portable II is putting out at least 10V, it's possible it's providing enough power to make the circuit in the RIB-Less cable work. The T3100e, since it's 2V lower at 8.4V, may not be enough to fully power the cable. I have another RIB-Less cable for a different radio, but it needs a 9V battery to work.