bugs found on eo

Emulator and emulator development specific topics
dr beep
Posts: 1165
Joined: Thu Jun 16, 2011 8:35 am
Location: Boxmeer

Re: bugs found on eo

Post by dr beep » Sun Apr 21, 2019 11:29 am

It looks like my game POLICE PATROL isn't accepting keyinput anymore.

I have loaded multiple versions of the game, even version in a downloadlink that I have marked OK for distribution.
games.zip
(229.15 KiB) Downloaded 5 times

dr beep
Posts: 1165
Joined: Thu Jun 16, 2011 8:35 am
Location: Boxmeer

Re: bugs found on eo

Post by dr beep » Sun Apr 21, 2019 11:35 am

Looks like all versions were corrupt somehow. Altered the code a bit.
Now working.

dr beep
Posts: 1165
Joined: Thu Jun 16, 2011 8:35 am
Location: Boxmeer

Re: bugs found on eo

Post by dr beep » Sat Apr 27, 2019 4:32 pm

Is opcode 9 wrong in emulation?

I tried same code in EightyOne and on ZX Spin.

LD HL,#FAFF
LD BC,#501
ADD HL,BC

RET Z

In EightyOne the Z-flag is not set when result is #100000 (1 goes to C-flag, but HL becomes 0, thus Z is set)
bug_EO.png

olofsen
Posts: 158
Joined: Wed Jan 08, 2014 12:29 pm

Re: bugs found on eo

Post by olofsen » Sat Apr 27, 2019 4:57 pm

Per design, the Z condition bit is not affected by ADD HL,BC...

dr beep
Posts: 1165
Joined: Thu Jun 16, 2011 8:35 am
Location: Boxmeer

Re: bugs found on eo

Post by dr beep » Sat Apr 27, 2019 5:18 pm

So it is a bug in ZX Spin.

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