Re: Asm graphics

 BBS: Inland Empire Archive
Date: 03-23-93 (21:31)             Number: 331
From: BOB SEWELL                   Refer#: NONE
  To: RICH GELDREICH                Recvd: NO  
Subj: Re: Asm graphics               Conf: (2) Quik_Bas
 In what possibly was a momentary lapse of reason, Rich Geldreich said:

 RG>    It sounds like you're not resetting everything back to what QB
 RG> expects it to be. I never could remember that they're called, but are
 RG> you messing with port 03C4h and port 03C5h, the write plane select
 RG> register? QB expects that to be set to 0Fh, or otherwise everything

     Actually, it's ports 03ceh and 03cfh. I'll post the code that sets and
(supposedly) resets these ports.

        mov     dx, 3ceh         ; prep EGA register to set mode
        mov     al, 5            ;              "
        out     dx, al           ;              "
        inc     dx               ; set EGA graphics write mode 2
        mov     ax, 2            ;              "
        out     dx, al           ;              "

        mov     dx, 3ceh         ; prep EGA register to set mode
        mov     ax, 5            ;              "
        out     dx, al           ;              "
        xor     ax, ax           ; set EGA write mode 0
        inc     dx               ;              "
        out     dx, al           ;              "

     So, you think maybe that last "out" should be with a 0fh rather than a
0h in the AL register?

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