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itty-bitty-vtty
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reformat scc magic constants

This commit is contained in:
Kelvin Sherlock 2021-10-17 19:33:28 -04:00
parent 892aed32f4
commit f13947a9c2
1 changed files with 14 additions and 10 deletions
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24
vt100.modem.S
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@ -29,7 +29,7 @@ init_modem ent
* sep #$30
* reset channel B (modem port)
ldx #9
lda #%01010001
lda #%01_0_1_0_0_0_1
stx SCCBREG
sta SCCBREG
nop
@ -37,24 +37,28 @@ init_modem ent
* x16 clock mode, 1 stop bit, no parity
ldx #4
lda #%01000100
lda #%01_00_01_0_0
stx SCCBREG
sta SCCBREG
* 8 bits/char, rx disabled.
ldx #3
lda #%11000000
lda #%11_0_0_0_0_0_0
stx SCCBREG
sta SCCBREG
* 8 data bits, RTS
ldx #5
lda #%01100010
lda #%0_11_0_0_0_1_0
stx SCCBREG
sta SCCBREG
* bit 7 = 1 for printer port, 0 for modem port.
* 5/6 = (%10) rcv clock = br output
* 4/3 = (%10) tx clock = br output
ldx #11
lda #%01010000
lda #%0_10_10_0_00
stx SCCBREG
sta SCCBREG
@ -79,7 +83,7 @@ init_modem ent
* enable baud rate generator
ldx #14
lda #%00000001
lda #%000_0_0_0_0_1
stx SCCBREG
sta SCCBREG
@ -87,14 +91,14 @@ init_modem ent
* 8 bits/char, rx enabled.
ldx #3
lda #%11000001
lda #%11_0_0_0_0_0_1
stx SCCBREG
sta SCCBREG
* 8 data bits, tx enabled, RTS
ldx #5
lda #%01101010
lda #%0_11_0_1_0_1_0
stx SCCBREG
sta SCCBREG
@ -106,7 +110,7 @@ init_modem ent
* reset ext/status interrupts
ldx #0
lda #%00010000
lda #%00_010_0_00
stx SCCBREG
sta SCCBREG
@ -122,7 +126,7 @@ init_modem ent
* status, visible, master interrupts disabled
ldx #9
lda #%00010001
lda #%00_0_1_0_0_0_1
stx SCCBREG
sta SCCBREG
nop