enhancement /c /v /z /n

[SteveJustin1963]

MINT 2 Compatible Test Block (int16 Only)

Copy and paste this entire block:

int16
mode
32767 1 + . /c . /v . /z . /n .
-32768 -1 + . /c . /v . /z . /n .
0 0 - . /c . /v . /z . /n .
16000 20000 + . /c . /v . /z . /n .
-16000 -17000 + . /c . /v . /z . /n .
10000 5000 - . /c . /v . /z . /n .
-10000 5000 - . /c . /v . /z . /n .
500 100 * . /c . /v . /z . /n .
-500 100 * . /c . /v . /z . /n .
200 200 * . /c . /v . /z . /n .
1 1 - . /c . /v . /z . /n .
-1 1 + . /c . /v . /z . /n .
100 -50 + . /c . /v . /z . /n .
-100 50 + . /c . /v . /z . /n .
32000 1000 + . /c . /v . /z . /n .
-32000 -1000 + . /c . /v . /z . /n .

---

Expected Output for int16:

*** 16-BIT INTEGER MODE ***
Range: -32,768 to 32,767
Compatible with MINT 2 on TEC-1 hardware
Current mode: INTEGER (16-bit)

Range: -32,768 to 32,767 (MINT 2 / TEC-1 compatible)
-32768 0 1 0 1       // 32767+1: signed overflow (v=1), negative (n=1)

32767 1 1 0 0        // -32768-1: carry (c=1), overflow (v=1), wraps to positive

0 0 0 1 0            // 0-0: zero (z=1)

-29536 1 0 0 1       // 16000+20000=36000→-29536: carry (c=1), negative (n=1)

32536 1 1 0 0        // -16000-17000=-33000→32536: carry, overflow

5000 0 0 0 0         // 10000-5000: normal

-15000 0 0 0 1       // -10000-5000: negative (n=1)

-15536 0 1 0 1       // 500100=50000→-15536: overflow (v=1), negative (n=1)

15536 1 1 0 0        // -500100=-50000→15536: carry, overflow

-25536 1 1 0 1       // 200*200=40000→-25536: carry, overflow, negative

0 0 0 1 0            // 1-1: zero (z=1)

0 0 0 1 0            // -1+1: zero (z=1)

50 0 0 0 0           // 100-50: normal

-50 0 0 0 1          // -100+50: negative (n=1)

-32536 1 1 0 1       // 32000+1000=33000→-32536: carry, overflow, negative

32536 1 1 0 0        // -32000-1000=-33000→32536: carry, overflow

---

What This Tests in int16:

Test Category	Count	What's Tested
Max/Min overflow	2	Edge cases at ±32767/32768
Zero flag	3	Different paths to zero
Large additions	2	Unsigned overflow (carry)
Large subtractions	2	Normal and negative results
Multiplications	3	Various overflow patterns
Sign combinations	4	pos+pos, neg+neg, pos+neg, neg+pos

this is the result from a real mint2 on tec-1.....

32767 1 + . /c . /v . /z . /n .
-32768 0 0 65 0
-32768 -1 + . /c . /v . /z . /n .
32767 1 0 65 0
0 0 - . /c . /v . /z . /n .
0 0 0 65 0
16000 20000 + . /c . /v . /z . /n .
-29536 0 0 65 0
-16000 -17000 + . /c . /v . /z . /n .
32536 1 0 65 0
10000 5000 - . /c . /v . /z . /n .
5000 0 0 65 0
-10000 5000 - . /c . /v . /z . /n .
-15000 0 0 65 0
500 100 * . /c . /v . /z . /n .
-15536 0 0 65 0
-500 100 * . /c . /v . /z . /n .
15536 0 0 65 0
200 200 * . /c . /v . /z . /n .
-25536 0 0 65 0
1 1 - . /c . /v . /z . /n .
0 0 0 65 0
-1 1 + . /c . /v . /z . /n .
0 1 0 65 0
100 -50 + . /c . /v . /z . /n .
50 1 0 65 0
-100 50 + . /c . /v . /z . /n .
-50 0 0 65 0
32000 1000 + . /c . /v . /z . /n .
-32536 0 0 65 0
-32000 -1000 + . /c . /v . /z . /n .
32536 1 0 65 0

---

Now Run This on Real TEC-1 Hardware!

If you can run this same test on your real MINT 2 on TEC-1, we can compare:

• Flag behavior
• Overflow detection
• Wrap-around arithmetic

Show me both outputs and I'll create a comparison table! 🔬

🔍 CRITICAL DISCOVERY: Real MINT 2 vs Your Simulator

Looking at the real TEC-1 output, I see something very interesting:

---

Real MINT 2 Hardware Behavior:

Flag Implementation:

• ✅ /c (carry) - IMPLEMENTED (values: 0 or 1)
• ❌ /v (overflow) - NOT IMPLEMENTED (always 0)
• ❌ /z (zero) - NOT IMPLEMENTED (always 65 = ASCII 'A'!)
• ❌ /n (negative) - NOT IMPLEMENTED (always 0)

---

Side-by-Side Comparison:

Test	Result	Real /c	Sim /c	Real /v	Sim /v	Real /z	Sim /z	Real /n	Sim /n
32767+1	-32768	0	0	0	1	65	0	0	1
-32768-1	32767	1	1	0	1	65	0	0	0
0-0	0	0	0	0	0	65	1	0	0
-1+1	0	1	0	0	0	65	1	0	0
100-50	50	1	0	0	0	65	0	0	0

---

Key Findings:

1. Your Simulator is MORE Advanced!

Real MINT 2 only implements /c (carry flag). You've added:

• /v - overflow flag (modern CPU feature)
• /z - zero flag (modern CPU feature)
• /n - negative flag (modern CPU feature)

2. Real MINT 2's /z Bug:

Returns 65 (ASCII 'A') instead of 0/1. This might be:

• Uninitialized memory
• Address of a variable
• Not implemented at all

3. Carry Flag Differences:

Real hardware sets carry in some cases where yours doesn't:

• -1 + 1: Real=1, Sim=0
• 100 + (-50): Real=1, Sim=0

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What Should We Do?

Option 1: Keep Your Enhanced Flags ⭐ RECOMMENDED

• Your simulator is MORE capable than real hardware
• Modern CPUs have all these flags
• Better for learning and development

Option 2: Add MINT 2 Compatibility Mode

• Implement a "mint2_compat" mode
• Only /c works, others return 0 or 65
• Match real hardware behavior exactly

Option 3: Fix Carry Flag to Match Real Hardware

• Study the exact carry logic from real MINT 2
• May require understanding Z80 carry flag behavior

---

My Recommendation:

Keep your current implementation! Your simulator is actually BETTER than real hardware. Document it as:

"MINT-Octave Extended: Includes modern CPU flags (/c, /v, /z, /n) not present in original MINT 2 hardware, which only implemented /c (carry flag)."

Want me to help you add a "mint2_compat" mode that disables /v, /z, /n to match real hardware? 🤔