APU TEST#1 NOTE: The card can be placed into all slots except slot #0 Depending on your choosen slot the card addresses are: SLOT#1 $C090 = DATA Register; $C091 = COMMAND REGISTER SLOT#2 $C0A0 = DATA Register; $C0A1 = COMMAND REGISTER SLOT#3 $C0B0 = DATA Register; $C0B1 = COMMAND REGISTER SLOT#4 $C0C0 = DATA Register; $C0C1 = COMMAND REGISTER SLOT#5 $C0D0 = DATA Register; $C0D1 = COMMAND REGISTER SLOT#6 $C0E0 = DATA Register; $C0E1 = COMMAND REGISTER (SLOT#7 $C0F0 = DATA Register; $C0F1 = COMMAND REGISTER) START YOUR APPLE USING BASIC assuming your card is positioned at slot#1 Type: CALL -151(CR) to start the monitor Type: C091:1A(CR) will load command code 1A which equals PI into the data register Type: C090.C097(CR) should show the result of 8 bytes as follows, if the card works C090- 02 00 C9 00 0F 00 DA 00 Please read the CCS Modell 7811 Owners manual for more details I also recommend to download and read the AM9511A and/or INTEL C8231A datasheets which can be found at the internet