Service Forum

wolfman · Last edited by wolfman on Thu Dec 01, 2005 4:53 am; edited 1 time in total

Are the capacitors used in the driven circuit polarized? Your circuit diagram does not indicate this, but other references to the Maxim232A IC do show polarized caps.

I ask because I'm having trouble getting my interface running--either that or my cmos is corrupt (IBMpass returns junk); I'd rather it was a problem with the circuit! I first built it with polarized electrolytic caps but am going to substitute plain ceramic caps this evening and see how that works.

Thanks for your help--this is a wonderful resource! I built the driven circuit on a breadboard and will post pictures here if you'd like, for those like me whose electronics courses were several decades ago and had to look up a lot of stuff.

victor · S.F. Boss Joined: 07 Mar 2004 Posts: 2581 Location: Staff

MAX232A doesn't need elcos. There are only unpolarised capacitors 0.1 uf = 100nf.
Check the circuit carefully, specially D1R2 -D2R1 area.

wolfman · Last edited by wolfman on Thu Dec 01, 2005 4:54 am; edited 1 time in total

Thanks!

So, if the bin file read by the simple circuit gives nonsense where the password should be, should I expect any different from the driven circuit? This happens with IBMpass lite and 2.0, original and alt scan codes formats.

I get an error that the time/date are bad before the password prompt. The cmos battery had discharged and had to be replaced. This is a T22.

If this does indicate corruption I'll send you my bin and cash and have it repaired and license the writer module.

victor · S.F. Boss Joined: 07 Mar 2004 Posts: 2581 Location: Staff

SIPROG works very well on t22. If is well built, of course.
So, SIPROG or driven-i2cprog the results have to be the same. Maybe you could send the eeprom dump to see what you have read at support-at-allservice.ro.
Also some pictures of your work would be helpful

Cheers

wolfman · Posted: Fri Dec 02, 2005 5:30 am Post subject: when to power the driven circuit?

thanks!

I am pretty stubborn, so I'll persist until I get the driven circuit to work. I haven't had time to get back to it, and don't have a digital camera here; will borrow one and send pics.

Question--when should the circuit be powered--before or after connecting GND, SDA, SCL to the 24RF08?

Let me echo the other comments you've received about what a great service you provide. The entire rest of the 'net seems empty of help on this topic, and I'm not about to buy a new motherboard for a four-year-old laptop--your circuit and programs are going to be my salvation!

bob · Posted: Sun Dec 04, 2005 1:55 am Post subject:

The circuit must be powered before. So, connect the circuit to the serial port and power on. Turn on the laptop, connect the wires and read. That's it.

I saw plenty of Arizona guys around here lately. Smile

Welcome to the board!