I think i'm in trouble sbc44uc boot gone?

[Tom@Nottingham]

I have had this board about 2 weeks and it is based around a Pic18f4550cpu together with picbasicPro. To download programs I have used the mplabs software via the usb connection etc. I have succeeded in getting the "HELLO WORLD" program to work in hyperterminal etc. I then tried to load a demo in pbp.bas and then to .hex then to pic4550. Unfortunately I ignored the warning about bootloader may be damaged when downloading program as I thought it was write protected, but it is not?. Nothing will download now, and all I get is access violation 00407880 in module etc.

Has anyone any ideas please?

Thanks

ps I have an old epic plus serial programmer, the pic however is surface mount?.

[skimask]

I have had this board about 2 weeks and it is based around a Pic18f4550cpu together with picbasicPro. To download programs I have used the mplabs software via the usb connection etc. I have succeeded in getting the "HELLO WORLD" program to work in hyperterminal etc. I then tried to load a demo in pbp.bas and then to .hex then to pic4550. Unfortunately I ignored the warning about bootloader may be damaged when downloading program as I thought it was write protected, but it is not?. Nothing will download now, and all I get is access violation 00407880 in module etc.

Has anyone any ideas please?

Thanks

ps I have an old epic plus serial programmer, the pic however is surface mount?.

Yes, the PIC is surface mount, but a quick look at the website shows that the board has an ICSP connector built into it.
If you think you screwed up the bootloader, you should be able to reprogram the bootloader via the epic programmer (assuming it supports the '4550 and assuming the company will send you the file you need). Besides that, bootloaders are generally fairly well protected against overwriting themselves.

As far as the access violation goes, that sounds more like Windows/USB thing than a problem with the PIC board itself. I don't really see how the board could generate an 'access violation', unless the bootloader is screwed up in such a way that it can magically generate just the right messages for Windows...I don't see it happening though...
I think I would clean out your PC, get rid of everything PIC related, and reload from scratch...first the SBC programmer software (if there is any), then MPLAB 8.00 (plus any patches), then PBP 2.50 + the patch, then MCS 3.0.0.5....Work from the bottom to the top. I think it's easiest that way.

[Tom@Nottingham]

Hi

Apologies for my delay in replying. Story so far is - I tried to reset the sbc44 from other hard drive etc with fresh software but all to no avail. The program I had downloaded had somehow corrupted the boot loader and this meant that the program mode could not be entered and the led program mode indicator was not flashing as it should be.

I then ordered a k8076 kit programmer in order to reprogram the boot loader into the sbc via the icsp connector. Unfortunately this programmer requires a proper serial port and Windows XP. My laptop has no serial port but has XP. I have an old Win 98 computer with a proper serial port that I was hoping to use. Also the programming software supplied only supports the 2550 pic not the 4550.

While searching the internet I came across pc-prog (which you may be aware of) and noted it could work with my now-built serial programmer. This software is very good and I was able to reprogram the boot.hex bootloader program back into it and it then came back to life. (Software also works in Windows 98 and supports loads more pics.) Hopefully I can now continue where I left off.

Many thanks.