Answer some questions by RTFM

This commit is contained in:
Joshua Bell 2017-11-24 16:47:49 -08:00
parent a445735244
commit 34acbaf822

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@ -53,17 +53,17 @@ loop: lda driver,y
;; Configure SSC ;; Configure SSC
lda #%00001011 lda #%00001011
sta COMMAND sta COMMAND
lda #%10011110 ; 9600 baud, 8 data bits, 1 stop bit lda #%10011110 ; 9600 baud, 8 data bits, 2 stop bits
sta CONTROL sta CONTROL
: lda STATUS : lda STATUS
and #(1 << 4) ; transmit register empty? (bit 4) and #(1 << 4) ; transmit register empty? (bit 4)
beq :- ; nope, keep waiting beq :- ; nope, keep waiting
;; Send command ;; Send command
lda #('@' | $80) lda #('@' | $80) ; '@' command
sta TDREG sta TDREG
read_len := 7 ; read 7 bytes (?/M/D/Y/h/m/?) read_len := 7 ; read 7 bytes (w/m/d/y/H/M/S)
;; Read response, pushing to stack ;; Read response, pushing to stack
ldy #(read_len-1) ldy #(read_len-1)
@ -95,7 +95,7 @@ ready: lda RDREG
bpl rloop bpl rloop
;; Convert pushed response to ProDOS time field ;; Convert pushed response to ProDOS time field
pla ; ??? pla ; day of week (unused)
pla ; minute pla ; minute
sta TIMELO ; -- stored as-is (TIMELO 5-0) sta TIMELO ; -- stored as-is (TIMELO 5-0)
@ -120,7 +120,7 @@ ready: lda RDREG
sta DATELO sta DATELO
rol DATELO+1 rol DATELO+1
pla ; ??? pla ; seconds (unused)
;; Restore prior state ;; Restore prior state
done: pla ; restore saved command state done: pla ; restore saved command state