diff --git a/strint_test.asm b/strint_test.asm
index 4ac78b7..ccc68b5 100644
--- a/strint_test.asm
+++ b/strint_test.asm
@@ -1,126 +1,53 @@
-mov r1, 1
-mov r2, test1
-mov r3, test1_end
-mov r13, test1_pass
-jmp atoi_test
-test1_pass:
-
-mov r1, 2
-mov r2, test2
-mov r3, test2_end
-mov r13, test2_pass
-jmp atoi_test
-test2_pass:
-
-mov r1, 3
-mov r2, test3
-mov r3, test3_end
-mov r13, test3_pass
-jmp atoi_test
-test3_pass:
-
-mov r1, 4
-mov r2, test4
-mov r3, test4_end
-mov r13, test4_pass
-jmp atoi_test
-test4_pass:
-
-mov r1, 5
-mov r2, test5
-mov r3, test5_end
-mov r13, test5_pass
-jmp atoi_test
-test5_pass:
-
-mov r1, 6
-mov r2, test6
-mov r3, test6_end
-mov r13, test6_pass
-jmp atoi_test
-test6_pass:
-
-mov r1, 7
-mov r2, test7
-mov r3, test7_end
-mov r13, test7_pass
-jmp atoi_test
-test7_pass:
-
-mov r1, 8
-mov r2, test8
-mov r3, test8_end
-mov r13, test8_pass
-jmp atoi_test
-test8_pass:
-
-mov r1, 9
-mov r2, test9
-mov r3, test9_end
-mov r13, test9_pass
-jmp atoi_test
-test9_pass:
-
-success:
-jmp success
-
-; test strint.atoi
-; Arguments:
-; r1 - test number
-; r2 - test data label
-; r3 - test end-of-string label
-; Result:
-; void. Hangs in failure: on failure.
-; Clobbers:
-; r8 - test number
-; r9 - Expected result in r1
-; r10 - Expected result in r2
-; Notes:
-; Depends on atoi not clobbering r8-r10.
-atoi_test:
-mov r8, r1
-load_32 r9, [r2]
-add r1, r2, 4
-mov r10, r3
-push r13
+; test harness for strint.atoi
+; Registers:
+; r8 - test address
+; r9 - expected result
+; r10 - actual length
+; r11 - expected length
+mov r8, tests
+next_test:
+; Set up arguments and run test
+add r1, r8, 5          ; Start of test string
 mov r13, atoi_test_ret
 jmp stdlib.strint.atoi
 atoi_test_ret:
-pop r13
+
+; Load reference data
+load_32 r9, [r8]       ; Expected result
+sub r10, r2, r8
+sub r10, r10, 5        ; Actual string length
+add r11, r8, 4         ; Address of expected length
+load_8 r11, [r11]      ; Expected length
+
+; Verify results
 cmp r1, r9
-jne failure
-cmp r2, r10
-jne failure
-jmp r13
+incorrect_result: jne incorrect_result
+cmp r10, r11
+incorrect_length: jne incorrect_length
 
-failure:
-jmp failure
+; Next test
+add r8, r8, 0x10
+cmp r8, end_of_tests
+jl next_test
 
-test1: U32 0 "0"
-test1_end: "\0"
+; Done
+success: jmp success
 
-test2: U32 1 "1"
-test2_end: "\0"
-
-test3: U32 2 "2"
-test3_end: "\0"
-
-test4: U32 42 "42"
-test4_end: "\0"
-
-test5: U32 67 "67"
-test5_end: "lol\0"
-
-test6: U32 1690 "0x69a"
-test6_end: "\0"
-
-test7: U32 19 "023"
-test7_end: "9\0"
-
-test8: U32 11 "0b1011"
-test8_end: "\0"
-
-test9: U32 17 "0b10001"
-test9_end: "2\0"
 
 include stdlib
+
+
+@0x1000
+tests:
+; addr  result       inlen  instr
+@0x1000 U32 0        U8 0   "\0"
+@0x1010 U32 0        U8 1   "0\0"
+@0x1020 U32 1        U8 1   "1\0"
+@0x1030 U32 2        U8 1   "2\0"
+@0x1040 U32 42       U8 2   "42\0"
+@0x1050 U32 67       U8 2   "67lol\0"
+@0x1060 U32 0x69a    U8 5   "0x69a\0"
+@0x1070 U32 0o23     U8 3   "0239\0"
+@0x1080 U32 0b1011   U8 6   "0b1011\0"
+@0x1090 U32 0b10001  U8 7   "0b100012\0"
+end_of_tests: