Apple II User Manual

observed:

When BASIC stores a program on cassette, it inserts a CTRL/Z after the last line. The

AIM 65 Editor will strip off the CTRL/Z when it retrieves the program. Therefore,

before storing a BASIC program from the Editor, the user must insert a CTRL/Z

following the last line of the program.

H ATN IMPLEMENTATION

The ATN function (see Subject 307) can be programmed in RAM using the AIM 65 Mnemonic

Entry (I) and Alter Memory Locations (/) commands, as shown below. The program is written

for the AIM 65 with 4K bytes of RAM. The ATN function can be relocated elsewhere in memory

by changing the starting addresses of the instructions and constants, the conditional branch

addresses, the vector to the constants start address and the vector to the ATN function starT

address.

ATN FUNCTION CONSTANTS ENTERED BY ALTER MEMORY <M>

<M> = 0F80 XX XX XX XX Constants Starting Address = 0F80

</> = 0F80 0B 76 83 83 8

</> 0F84 BD D3 79 1E

</> 0F88 F4 A6 F5 7B

</> 0F8C 83 FC B0 10

</> 0F90 7C 0C 1F 67

</> 0F94 CA 7C DE 53

</> 0F98 CB C1 7D 14

</> OF9C 64 70 4C 7D

</> 0FA0 B7 EA 51. 7A

</> 0FA4 7D 63 30 88

</> 0FA8 7E 7E 92 44

</> 0FAC 99 3A 7E 4C

</> 0FR0 CC 91 C7 7F

</> 0FB4 AA AA AA 13

</> 0FR8 81 00 00 00

</> 0FBC 00

ATN FUNCTION INSTRUCTIONS STORED BY MNEMONIC ENTRY (I)

<I>

XXXX *=0FBD Instructions Starting Address = 0F8D

0FBD A5 LDA AE

0FBF 48 PHA

0FC0 10 BPL 0FC5

0FC2 20 JSR CCB8

0FC5 AS LDA A9

0FC7 48 PHA

0FC8 C9 CMP #81

0FCA 90 BCC 0FD3

0FCC A9 LDA #FB

0FCE A0 LDY #C6

0FD0 20 JSR C84E

0FD3 A9 LDA #80 \ Starting Address of Constants = 0F80

0FD5 A0 LDY #0F /

0FD7 20 JSR CD44

0FDA 68 PLA

0FDB C9 CMP #81

0FDD 90 BCC 0FE6

0FDF A9 LDA #4E

0FE1 A0 LDY #CE

0FE3 20 JSR C58F

0FE6 68 PLA

0FE7 10 BPL 0FEC

0FE9 4C JMP CCB8

0FEC 60 RTS

0FEC

BASIC INITIALIZATION FOR ATN FUNCTION

BASIC memory must be initialized below the memory allocated to the ATN function. The ATN

vector in RAM must also be changed from the address of the FC error message to the starting