Intel 8080 assembly

README.md

@@ -103,7 +103,7 @@ This repository tracks a [misguided quest to write code in 100 different program
 | 94 | [Almost Equilateral Triangles](https://projecteuler.net/problem=94) | TBD |  |
 | 95 | [Amicable Chains](https://projecteuler.net/problem=95) | TBD |  |
 | 96 | [Su Doku](https://projecteuler.net/problem=96) | [Prolog](https://en.wikipedia.org/wiki/Prolog) ([SWI-Prolog](https://www.swi-prolog.org/)) | [p96.pro](src/p96.pro) |
-| 97 | [Large Non-Mersenne Prime](https://projecteuler.net/problem=97) | TBD |  |
+| 97 | [Large Non-Mersenne Prime](https://projecteuler.net/problem=97) | [8080](https://en.wikipedia.org/wiki/Intel_8080) assembly ([Altair 8800](https://en.wikipedia.org/wiki/Altair_8800)) | [p97.asm](src/p97.asm) |
 | 98 | [Anagramic Squares](https://projecteuler.net/problem=98) | TBD |  |
 | 99 | [Largest Exponential](https://projecteuler.net/problem=99) | TBD |  |
 | 100 | [Arranged Probability](https://projecteuler.net/problem=100) | TBD |  |

src/p97.asm

@@ -0,0 +1,77 @@
+main:
+    ; Add binary-coded decimal digits (10 digits, 5 bytes)
+    lda digits
+    add a
+    daa
+    sta digits
+    lda digits+1
+    adc a
+    daa
+    sta digits+1
+    lda digits+2
+    adc a
+    daa
+    sta digits+2
+    lda digits+3
+    adc a
+    daa
+    sta digits+3
+    lda digits+4
+    adc a
+    daa
+    sta digits+4
+
+    ; Update counter
+    lda counter
+    sui 1
+    sta counter
+    lda counter+1
+    sbi 0
+    sta counter+1
+    lda counter+2
+    sbi 0
+    sta counter+2
+    lda counter+3
+    sbi 0
+    sta counter+3
+
+    # Loop if needed
+    lda counter
+    adi 0
+    jnz main
+    lda counter+1
+    adi 0
+    jnz main
+    lda counter+2
+    adi 0
+    jnz main
+    lda counter+3
+    adi 0
+    jnz main
+
+    ; Add one, as given in the problem
+    lda digits
+    adi 1 ; TODO
+    sta digits
+
+    ; All done; inspect "digits" for resulting digits
+    hlt
+
+    ; Store data at 0xe0
+    org 0eh
+
+digits:
+    ; 28433 as 10 packed binary coded decimal digits (little-endian)
+    db 33h
+    db 84h
+    db 02h
+    db 00h
+    db 00h
+
+counter:
+    ; 7830457 as 32-bit little-endian
+    db 0b9h
+    db 7bh
+    db 77h
+    db 00h
+