Fixed issue with IN and OUT instructions to support the upper byte of the address

[abelykh0]

I was testing Sinclair emulator and realized that BREAK in BASIC didn't work. My changes fix this.

Their code for BREAK is like this:
1F54 BREAK-KEY
LD A,+7F Form the port address
IN A,(+FE) +7FFE and read in a byte.
RRA Examine only bit 0 by shifting
it into the carry position.
RET C Return if the BREAK key is
not being pressed.
LD A,+FE Form the port address
IN A,(+FE) +FEFE and read in a byte.
RRA Again examine bit 0.
RET Return with carry reset if
both keys are being pressed.

[anotherlin]

Hi Andrey,

Thank you for reporting and fixing that bug.
I totally missed the fact that the port address may be 16-bit.
My targeted device (Sega Master System) makes only use of 8-bit.
I've double checked the Z80 User's manual.
And the output instructions will also need to be fixed as the upper 8-bit of the address is also relevant.
I'll work on that.

Best regards,

[leighbb]

@abelykh0 @anotherlin
I think it would better to simply specify the port as a 16-bit value in the Z80_INPUT_BYTE and Z80_OUTPUT_BYTE macros. Also, we should update the documentation for those macros in
z80user.h.

I have created a branch in my fork with those proposed changes. I'm not sure the best way to
reference them, so here is a link to the branch:

leighbb/z80emu 16_bit_port branch

I'm not an expert on github but I can send a patch or create a separate pull request if you like this approach.

Cheers,

Leigh.

[abelykh0]

That's fine with me. Whatever seems more logical to @anotherlin.

[anotherlin]

Hi everyone, I've been quite busy lately and I haven't had time to work on this project. I'll have a look this week-end. Thank you for your interest and contribution. Best regards,

…

On Thu, Jun 20, 2019 at 8:02 PM Andrey Belykh ***@***.***> wrote: That's fine with me. Whatever seems more logical to @anotherlin <https://github.com/anotherlin>. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#8?email_source=notifications&email_token=AAIIOQO4YJM2QK6DPWE4FZDP3PA2HA5CNFSM4FHRBWBKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGODYGFKMA#issuecomment-504124720>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAIIOQJNTWNAXOYTWAZX6OLP3PA2HANCNFSM4FHRBWBA> .

-- /* Lin Ke-Fong * [email protected] * I always do what I say, especially if it's something stupid. */