Using a W65c02 Simulator:

'Search n Go' Function

Overview:

A portion of the SBC30 code has been sliced and edited as  SBC30_TEST_SEARCH_02.asm for the Search For & Execute a Program function (Search N Go) that is executed by typing "G" or "g" in the terminal.

In the Sim the user is prompted:

1) To select a starting address for the search. Example: $8000

2) To select a starting address of the programs found. Example: $8029 which is where the ASCII program is located.

Tester:

Oshonsoft 6502 Simulator IDE v1.41

Setup:

Setup your IDE as shown in the top screenshot.

In the Peripheral Devices window:

- set Device 1 to be an INput on port $5000 with a One-Shot IN value of 47 (for the letter G)

- Set Output Terminal to I/O Port $5000

- Set Input Terminal to I/O Port $5000

- Send Hex Bytes 38,30,30,30,38,30,32,39.  (8000, 8029)

Adjust the 3 Memory Editors to show addresses $0000, $0200 and $8000.

In the Watch Variables window, you may wish to add:

- EAcnt_LoHi at $0034

- EAloc_LoHi at $0036

- PCnt_LoHi at $0038

- AddrLoHi at $0006

SIM Breakpoints:

The only BPs needed are at 906 and 908 to show the JuMP to address $8029 found in AddrLoHi at $0006, as well as the usual RTS.

Use <CTRL><F6> to get you to the breakpoints, use <F2> at each to get a feel for what is occurring, then continue to the next BP using <CTRL><F6>.

App Operation:

Using the FlashROM code and not the Sim, here are the keystrokes needed to produce the adjacent lower screenshot:

- Press Reset button

- G

- 8000

- 8B9D

IDE Operation:

If you wish to burn the code to flashROM, try this latest build: SBC30_0_R8.bin

Oshonsoft 6502 Simulator IDE

(Click to Enlarge)

Sim IDE

ASCII Terminal