Because some people do have problems every time they try to set PMG, here is simple example showing "A" letter using PMG with mentioning which setting is obligatory and which not. In addition, in normal "legal" use (system interrupts on), shadow-registers must be used or else efect of writing to registers lasts for at most 1 frame.
It is worth noting, that PMG is drawn by ANTIC (GTIA is fed with bytes read by ANTIC dma), thus some registers belong to ANTIC, some to GTIA.
org $4000
; to avoid blink, here should be a loop waiting for interrupt
lda #%111110 ; obligatory, double line, no missle DMA;
sta $22f ; DMACTL - 62 - single line, normal playfield
lda #$80 ; obligatory
sta $D407 ; PMBASE
lda #$7c ; obligatory
sta $D000 ; HPOSP
lda #1 ; default is good for this example, may be skipped
sta $26f ; first PM then PF
lda #%11 ; obligatory
sta $D01D ; GRACTL -set both players and missles
lda #2 ; default is good for this example, may be skipped
sta $D008 ; SIZEP
lda #$2f ; this is the color of the
sta $2c0 ; PCOLR0, surely may be skipped.
ldx #7
; let's display 'A' letter
show
lda $e108,x ; get 'A' letter rows from char generator
sta $8440,x ; store it in PLAYER0 memory chunk.
dex
bpl show ; do it eight times
end
bne end ; wait for eternity.