From 6c910757d995643d49923f8081c735b752c47ea6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20L=C3=B6fgren?= <henrik.lofgren@gmail.com>
Date: Sat, 31 Aug 2024 19:15:26 +0200
Subject: [PATCH 1/4] Added serial driver
---
src/arch/nano6502/nano6502.S | 94 +++++++++++++++++++++++++++++++++++-
1 file changed, 92 insertions(+), 2 deletions(-)
diff --git a/src/arch/nano6502/nano6502.S b/src/arch/nano6502/nano6502.S
index c679f892..404297e9 100644
--- a/src/arch/nano6502/nano6502.S
+++ b/src/arch/nano6502/nano6502.S
@@ -54,6 +54,11 @@ uart_tx_done = $fe01
uart_rx_data = $fe02
uart_rx_avail = $fe03
+uart_b_tx_data = $fe04
+uart_b_tx_done = $fe05
+uart_b_rx_data = $fe06
+uart_b_rx_avail = $fe07
+
keyb_data_avail = $fe00
keyb_data = $fe01
@@ -309,7 +314,7 @@ zproc tty_conin
lda pending_key
zif_eq
tty_input_wait:
- lda #IO_page_uart
+ lda #IO_page_uart
sta IO_page_reg
lda uart_rx_avail
beq tty_input_keyb
@@ -347,7 +352,7 @@ zendproc
; --- SCREEN driver -------------------------------------------------------
-defdriver SCREEN, DRVID_SCREEN, drvstrat_SCREEN, 0
+defdriver SCREEN, DRVID_SCREEN, drvstrat_SCREEN, drv_SERIAL
; SCREEN driver strategy routine
; Y = TTY opcode
@@ -548,6 +553,91 @@ normal_style:
rts
zendproc
+; SERIAL driver strategy routine
+; Y = TTY opcode
+
+defdriver "SERIAL", DRVID_SERIAL, drvstrat_SERIAL, 0
+
+zproc drvstrat_SERIAL
+ jmpdispatch serial_jmptable_lo, serial_jmptable_hi
+
+serial_jmptable_lo:
+ jmptablo serial_inp
+ jmptablo serial_out
+ jmptablo serial_open
+ jmptablo serial_close
+ jmptablo serial_outp
+ jmptablo serial_in
+serial_jmptable_hi:
+ jmptabhi serial_inp
+ jmptabhi serial_out
+ jmptabhi serial_open
+ jmptabhi serial_close
+ jmptabhi serial_outp
+ jmptabhi serial_in
+zendproc
+
+; SERIAL driver
+
+zproc serial_inp
+ lda #IO_page_uart
+ sta IO_page_reg
+ lda uart_b_rx_avail
+ zif_eq
+ ; No data available
+ sec
+ rts
+ zendif
+ lda uart_b_rx_data
+ clc
+ rts
+zendproc
+
+zproc serial_out
+ tax
+ lda #IO_page_uart
+ sta IO_page_reg
+wait_serial_out:
+ lda uart_b_tx_done
+ beq wait_serial_out
+
+ txa
+ sta uart_b_tx_data
+ rts
+zendproc
+
+serial_open:
+serial_close:
+rts
+
+zproc serial_outp
+ tax
+ lda #IO_page_uart
+ sta IO_page_reg
+
+ lda uart_b_tx_done
+ zif_eq
+ sec
+ rts
+ zendif
+ txa
+ sta uart_b_tx_data
+ clc
+ rts
+zendproc
+
+zproc serial_in
+ lda #IO_page_uart
+ sta IO_page_reg
+
+wait_serial_in:
+ lda uart_b_rx_avail
+ beq wait_serial_in
+
+ lda uart_b_rx_data
+ rts
+zendproc
+
; -- Rest of the BIOS ---
; Sets the current DMA address.
From 7f126c7a0e2177301ff5281ccb5029f870ec7748 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20L=C3=B6fgren?= <henrik.lofgren@gmail.com>
Date: Sat, 31 Aug 2024 19:59:59 +0200
Subject: [PATCH 2/4] Avoid messing up the X register
---
src/arch/nano6502/nano6502.S | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/src/arch/nano6502/nano6502.S b/src/arch/nano6502/nano6502.S
index 404297e9..487c5880 100644
--- a/src/arch/nano6502/nano6502.S
+++ b/src/arch/nano6502/nano6502.S
@@ -594,14 +594,14 @@ zproc serial_inp
zendproc
zproc serial_out
- tax
+ sta ptr
lda #IO_page_uart
sta IO_page_reg
wait_serial_out:
lda uart_b_tx_done
beq wait_serial_out
- txa
+ lda ptr
sta uart_b_tx_data
rts
zendproc
@@ -611,7 +611,7 @@ serial_close:
rts
zproc serial_outp
- tax
+ sta ptr
lda #IO_page_uart
sta IO_page_reg
@@ -620,7 +620,7 @@ zproc serial_outp
sec
rts
zendif
- txa
+ lda ptr
sta uart_b_tx_data
clc
rts
From 23dd2912ef512d09a1b337d95a1df71ad070c3c0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20L=C3=B6fgren?= <henrik.lofgren@gmail.com>
Date: Thu, 5 Sep 2024 10:28:42 +0200
Subject: [PATCH 3/4] Clean up of comments
---
src/arch/nano6502/nano6502.S | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/src/arch/nano6502/nano6502.S b/src/arch/nano6502/nano6502.S
index 487c5880..eeb2efe1 100644
--- a/src/arch/nano6502/nano6502.S
+++ b/src/arch/nano6502/nano6502.S
@@ -355,7 +355,7 @@ zendproc
defdriver SCREEN, DRVID_SCREEN, drvstrat_SCREEN, drv_SERIAL
; SCREEN driver strategy routine
-; Y = TTY opcode
+; Y = SCREEN opcode
zproc drvstrat_SCREEN
jmpdispatch screen_jmptable_lo, screen_jmptable_hi
@@ -553,8 +553,11 @@ normal_style:
rts
zendproc
+
+; --- SERIAL driver -------------------------------------------------------
+
; SERIAL driver strategy routine
-; Y = TTY opcode
+; Y = SERIAL opcode
defdriver "SERIAL", DRVID_SERIAL, drvstrat_SERIAL, 0
@@ -577,8 +580,6 @@ serial_jmptable_hi:
jmptabhi serial_in
zendproc
-; SERIAL driver
-
zproc serial_inp
lda #IO_page_uart
sta IO_page_reg
From a16cf0d51d7d10de6626d7e955762cd0f3eed015 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20L=C3=B6fgren?=
<106430829+venomix666@users.noreply.github.com>
Date: Thu, 5 Sep 2024 17:24:05 +0200
Subject: [PATCH 4/4] Update README.md with info on nano6502 SERIAL driver
---
README.md | 1 +
1 file changed, 1 insertion(+)
diff --git a/README.md b/README.md
index 781ce756..939e3135 100644
--- a/README.md
+++ b/README.md
@@ -334,6 +334,7 @@ the same time.
- To use, write the `nano6502.img` file into the SD-card using `dd` or your preferred SD-card image writer. If you are updating the image and want to preserve the data on all drives except `A`, write the `nano6502_sysonly.img` instead.
- User area 1 on drive `A` contains utilities for setting the text and background colors, and a demo application which blinks the onboard LEDs.
+ - A SERIAL driver is available for the second UART, connected to pin 25 (RX) and 26 (TX) of the FPGA (and the UART header on the nanoComp carrier board). The baudrate is currently fixed to 115200.
### KIM-1 with K-1013 FDC notes