Dataman Forum

Hi

I have a Dell Latitude C840 (P4 2Ghz) notebook running Win2K.

My S4 is connected to the onboard COM1 serial port.

Even at 28.8kbps I cannot reliably receive a HEX file from my Dataman S4, even when using hardware flow control.

I end up with dropped characters, so, instead of 20H data bytes per Intel Hex record, I might end up with a few missing.

Thus, the resulting HEX file being written to my hard disk is corrupted. So much for the idea of using my S4 to make backups of my valuable EPROMs.

I am using S4 driver V2.04 (the latest), and library PROM version 2.93.

What REALLY annoys me is that the PC-based driver program does not even perform a basic integrity check on the received data being written into the HEX file. At least this would indicate that there is a problem with my serial communications, and I would know not to trust the HEX file.

I know that DELL Laptops have a problem sometimes with serial communications because there is some non-standard hardware for the UARTs, i.e. the multifunction I/O chips they use do not emulate a 16550 completely accurately.

I also know from experience that certain serial communications packages do far better under heavy load than others. WRQ Inc's "Reflection" package is far better than Hyperterminal.

I can get around DELL's problems by adding a PCMCIA serial port from SocketCom (excellent and worth the money !!!) however this is no excuse for the S4 PC-based driver to not validate the received HEX file.

Anybody else experienced problems using a DELL Notebook, or other system where HEX files are corrupted.

Please Dataman - how about fixing the PC-based S4 driver software to check the resulting HEX files ?

Cheers

Jason Armistead

Jason

Our engineer is looking into incorporating this in the software.

I will keep you updated here.

Neil

Yes - I cannot upload large hex files from the S4 to my PC without losing characters on my Win98 system - some lines are short. Also I always get a different checksum reported. If the S4 is clever enough to work out the ROM checksum from the hex data, then it could verify this checksum against the real checksum of the RAM in the S4.
I just haven't been able to upload a 512K byte (not 512K bit) EEPROM at any baud rate. I have Xon/Xoff enabled and I have played with the Windows COM buffer thresholds. Has anyone made thus work for large uploads?

Hi,

After thorough testing we do not have any problems at all. It may be that your computer is slow or has a slow serial interface.
Xon/Xoff does not work with S4, there is no place in code RAM for that.

Neil

Hi
I have disabled 16550 FIFO support in CP but still get errors.
What is strange is that the Examine file... panel after saving the hex file says
Binary length=$00080000 every time, but the file length and the checksum is different every time.

Have you tried uploading this length of file using just TX/RX/GND only in Intel Hex format?
My guess is that Windows cannot cope as it has to save to disk at some point ?? May depend on how much RAM is spare in Windows, etc.

Would it be possible to implement XON/XOFF on the S4 for HEX file xfer? Surely this could not take more than 20 lines of code or so and would be compatible (unless XON/XOFF is not trapped by Windows - then you will also have to update the comms driver too)?

Hi,
I have now made up a full h/shake cable and connected up an RS232 breakout box. During a S4>PC Transfer neither RTS CTS DSR or DTR never seem to go inactive (at least its not registering on the breakout box).
needless to say I still can't get reliable large uploads even with a full handshake cable as in the S4 manual. Using FLASH 1.12 with 512K RAM.

The fault is DEFINITELY with the DELL C840's COM port implementation. This is not a slow system, it has a 2GHZ P4 processor in it. Yet the S4 is able to overrun the C840s COM port buffer at baud rates as slow as 19200 baud.

Other PCs, even way slower than a 2GHZ P4 do not have problems. This issue seems to be specific to DELL, and I've read other postings on Usenet and other bulletin boards about how bad the DELL COM ports are.

If I connect my S4 to a Socket Dual Serial PCMCIA card, the transfers are 100% rock solid. This is an EXCELLENT card indeed, and I'd recommend it to anyone wanting reliable COM ports (especially multiple ones for protocol analysis, etc) !

Cheers

Jason Armistead