Simple Frequency Generator #1
RCA 1802 Program
For use on the Elf2000
Mem Instructions Explanation
00 90 B6 Put R0.0 (00) into Reg 6 high
02 F8 30 A6 Load 30 into D and place into R6 low
05 E0 Set X to Reg 0
06 64 01 Output 01 to LEDs
08 E6 Set X to Reg 6
09 3F 09 If EF4 Input is Null go to 09 i.e., wait until toggled
0B 6C Get input from the Toggle switches (Data Bus)
0C 64 Display the data out the LEDs
0D 26 Decrement Reg 6
0E 37 0E Wait here until the main Input Toggle Switch goes low
10 F0 A1 Load the byte entered from M(R(X)) which is Reg 6 into D
Place D into Reg 1.0 as a counter to work down from
12 7B Switch Q light ON
13 32 22 If D is 00 then skip down to End (22)
15 21 81 Decrement Reg 1, and then get Reg 1.0 into D
17 3A 15 If D is NOT Null then go back and keep decrementing R1
19 F0 A1 Load the original byte entered from M(R(X)) (Reg 6) into D
Place D into Reg 1.0 as a counter to work down from
1B 7A Switch Q Light OFF
1C 21 81 Decrement Reg 1, and then get Reg 1.0 into D
1E 3A 1C If D is NOT Null then go back and keep decrementing R1
20 3F 10 If EF4 is Null then go back to 10 and keep this up
22 30 00 Else, Go to 00 and start over