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11

Without reading the manuals it seems that both vasm and tasm decides if an operand is a number or a label is decided from the first character. A number MUST start with a digit in the decimal range, anything starting with a letter is considered a label. So you need to enter the number as '0A000H'. So, when tasm finds an argument A000H it thinks it a label ...


5

TL;DR The various issues are due clocking. In part by using 'unconventional' ways of clock handling but as well by simply violating specs. Main points are SIO (and in fact CPU) are not static designs but dynamic. As such they requite certain clock speeds and relation. Clocking the system at 10 Hz violates a whole bunch of rules Minimum system clock speed ...


4

[Uncle Bod's answer nails it. Vote for him. This is more of a background add on.] The underlying issue is a hodgepodge of language and number mixup, further complicated by using a different notation when thinking about the problem (writing the question) as the one used within the code written. In the question the OP asks about 0x9FFF vs. 0xA000, which is a ...


4

Comments have already covered that the CPU manual should answer all your questions, but above and beyond that, immediate observations: ld (nn), bc is encoded as ed43 so that's two reads; the actual address, 0x1000 is also two bytes long, so that's another two reads; bc is two bytes long, so that must be two writes. In total that's six memory accesses, from ...


4

I see some issues, but since this is an assignment, I shouldn't provide a complete solid answer right away. However: There are many Z80 variants out there. You may want to know exactly which chip is being used. Personally, I would tend towards using HCT-series logic there if you need TTL compatibility. However, I believe the I/O may be CMOS. Look at the ...


1

This is how my emulator stores this instruction: ---------------------------------------------------------------------- |opc T0 T1 MC1 MC2 MC3 MC4 MC5 MC6 MC7 mnem | |--------------------------------------------------------------------| |ED43L1H1 20 00 M1R 4 M1R 4 MRD 3 MRD 3 MWR 3 MWR 3 ... 0 LD (U16),BC| ----------------------------...


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