Mountain Computer ROMPlus+ Operating Manual

Appendix ACONTROL ROM SOURCE LISTING48*'49*'50*'WE USE 3 DIFFERENT ENTRY51*'POINTS: "FIRST", FOR THE52*'INITIAL ENTRY AND "0ENTR'r'"5~. -' *'AND "IENTRY" FOR THE OUTPUT54*'AND INPUT RE-ENTRIES. THE55*'C AND V BITS ARE USED TO56*'REMEMBER WHICH ENTR'T' OCCUR ED.co"",-_, i*'6300: 2C 58 FF 58 FIRST BIT 10RTS SET ',/FLAG FOR INITIAL ENTRY6303: 38 59 SEC .. MAKE INITIAL ErHI':'T' OUTPUT6304: 70 04 60 BVS ENTF.:'r' AU~A'r'S TAKEN6306: 38 61 OENTR'T' SEC6307: 90 62 HD~ 90 mrCK TO SAVE A B'iTE6308: 18 63 I ENTRY CLC j HIDE A'- ::.' BRANCH OFFSET6309: B8 64 CLV6566*'*COMMON ENTF.:'!' POINT67 :+:630A: 48 68 ENTR'T' PHA630B: SA 69 TXAG30C: 48 70 PHA630(): 98 71 TVA630E: 48 7;;-! PHA630F: 08 73 PHP74 :+:75 :+: Nm~ ~,jE MUST FIND OUT WHAT SLOT76 :+: i4E "I