schlae / comix-35

The COMIX-35 is an improved clone of the COMX-35 1802 home computer
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Key auto-repeats under PAL setting #4

Open 0ddjob opened 21 hours ago

0ddjob commented 21 hours ago

Hi,

My machine is configured as PAL with Y1 = 17.73MHz and JP1/2/3 = PAL.

However the JP3 = PAL setting causes keys to auto-repeat with BASIC v1.03 and v1.04 (haven't tried others).

COMiX_35_key_autorepeat_PAL

When it is set to NTSC then the auto-repeat issue is solved, but the screen display is incorrect (top line is repeated at bottom).

COMiX_35_key_autorepeat_fixed

The diodes are installed as per the PCB silkscreen: D1 cathode north (PAL) and D2 cathode south (NTSC).

I can see that JP3 affects the RPT/RTP auto-repeat signal from the CDP1871 and the EF2 signal into the CDP1802 but I don't really understand why NTSC or PAL makes a difference.

Thanks!

Brett.