C172 PLT ENTERS ABE CLASS C AIRSPACE WITHOUT CLRNC.

Narrative

I WAS ABOUT 15 MI W OF ABE ARPT AT 2000 FT; TRAVELING E; CALLED APCH AND REQUESTED A TRANSITION THROUGH THEIR AIRSPACE AND THAT I HAD TFC IN SIGHT AT 10 O'CLOCK POS AND 2 MI. THEY REPLIED MAINTAIN VISUAL SEPARATION AND GAVE ME A SQUAWK CODE. MY GND SPD MUST HAVE BEEN AROUND 135 KTS AS THE WIND WAS FROM THE W AT ABOUT 20 KTS. WHILE I WAS WAITING FOR APPROVAL FOR THE TRANSITION THROUGH THEIR AIRSPACE; ABE APCH CONTACTED ME AND TOLD ME I HAD PENETRATED THEIR AIRSPACE; AND THAT I SHOULD TURN N TO A HDG OF 360 DEGS WHICH I IMMEDIATELY DID. IN RETROSPECT I SHOULD HAVE REALIZED MY POS TO THE CLASS C AIRSPACE WAS CLOSER THAN I THOUGHT AND THAT THE WINDS WOULD BRING ME CLOSER YET. I SHOULD HAVE AVOIDED THE CLASS C AIRSPACE ON MY OWN. I HAD A CURRENT SECTIONAL AND HAD REFERRED TO IT SEVERAL TIMES DURING THIS FLT; BUT BECAUSE THIS AREA BEING MY HOME AREA; I WAS NOT PAYING AS MUCH ATTN TO MY POS AS I SHOULD HAVE. AN ADDITIONAL DETAIL IS THAT THE SKYHAWK I WAS FLYING IS EQUIPPED WITH GPS WITH A MOVING MAP. HOWEVER; EVEN THOUGH I'VE FLOWN THIS AIRPLANE MANY TIMES; I'VE NEVER LEARNED HOW TO OPERATING THIS PARTICULAR GPS UNIT. BEFORE MY NEXT FLT; I WILL. AS AN ASIDE AND NO EXCUSE FOR MY ERROR; IT WOULD BE NICE IF ALL GPS UNITS HAD BEEN STANDARDIZED RELATIVE TO HOW THEY OPERATE THE WAY VOR RECEIVERS HAVE BEEN.