From 45dce42475e15968503dfceb867ef667dea72e8c Mon Sep 17 00:00:00 2001 From: "matthias@arch" Date: Wed, 27 Dec 2023 21:38:10 +0100 Subject: [PATCH] Revert "add keyboard" This reverts commit 302e49a9f79f8e2255b6227e7c3bf23c7f924c19. --- system/keyboard.h65 | 23 ---------- system/keyboard.s65 | 106 -------------------------------------------- 2 files changed, 129 deletions(-) delete mode 100644 system/keyboard.h65 delete mode 100644 system/keyboard.s65 diff --git a/system/keyboard.h65 b/system/keyboard.h65 deleted file mode 100644 index 8e3fa97..0000000 --- a/system/keyboard.h65 +++ /dev/null @@ -1,23 +0,0 @@ -;;******************************************************************************** -;; @module keyboard -;; @type drive -;; @details: -;; Support for a PS2 Keyboard using the shift register of a 6522 VIA -;; Pressing a key causes 11 bits to be sent: 1 start - 8 keycode - 1 parity - 1 stop -;; The VIA is set up to interrupt after 8 bits have been shifted into the shift register -;; from the external clock pulses of the keyboard (additional hardware required to -;; address the hardware bug of the VIA, where bit get lost when the external clock -;; transition happens during falling edge of PHI2). After reading the shift register, -;; the VIAs T2 timer is set to interrupt after the last 3 bits have been shifted in, -;; which takes about ~230ms. -;;******************************************************************************** -.ifndef INCLUDE_KEYBOARD -INCLUDE_KEYBOARD = 1 -.include "system.h65" - -.scope kb -Import kb,init,irq_shift_reg_handler,irq_timer_handler,keycode,key_read -KB_IO = IO1 - -.endscope -.endif diff --git a/system/keyboard.s65 b/system/keyboard.s65 deleted file mode 100644 index 17c369f..0000000 --- a/system/keyboard.s65 +++ /dev/null @@ -1,106 +0,0 @@ -.include "keyboard.h65" -.include "string.h65" -.include "lcd.h65" -Export kb,init,irq_shift_reg_handler,irq_timer_handler,keycode,key_read - -.bss -key_read: .res 2 -keycode: .res 1 - -.code -;;******************************************************************************** -;; @function Initialize the PS2 keyboard -;; @modifies: A -;;******************************************************************************** -.proc init - ; - use the shift register interrupts to read the first 8 bits - ; set shift register to shift in under external clock on CB1 - ; - configure timer for timing the read of the last 3 bits - ; timer 2 one shot mode is sufficient, leaves T1 available - lda #(IO::ACR::SR_SIN_PHIE | IO::ACR::T2_IRQ_LOAD) - tsb kb::KB_IO + IO::ACR - ; the 3 last bits take about 230us, at @1MHz => wait 230 cycles and then the shift register - ; (this could be shorter since the it takes a few cycles after the interrupt) - lda #230 - sta kb::KB_IO + IO::T2CL - stz key_read - stz key_read+1 - - ; enable SR interrupts - lda #(IO::IRQ::IRQ | IO::IRQ::SR) - sta kb::KB_IO + IO::IER - ; load SR to reset - lda kb::KB_IO + IO::SR - rts -.endproc - - -;;******************************************************************************** -;; @function Read the first 8 bits an -;; @modifies: A -;; @details -;; - read shift register -;; - disable shift register interrupts -;; - reset shift register -;; - enable timer 2 interrupts -;; - start timer 2 -;; IO::SR has to be read before the next bit is shifted in, which happens ~75us after the irq -;; at 1MHz, handling this interrupt takes about 50us (without any additional debug code), -;; so it should work -;;******************************************************************************** -.proc irq_shift_reg_handler - lda kb::KB_IO + IO::SR - sta key_read - stz kb::KB_IO + IO::SR - - ; disable SR interrupts - lda #IO::IRQ::SR - sta kb::KB_IO + IO::IER - ; enable timer interrupts - lda #(IO::IRQ::IRQ | IO::IRQ::T2) - sta kb::KB_IO + IO::IER - ; start timer, low order count already in latch after init - lda #1 - sta kb::KB_IO + IO::T2CH - rts -.endproc - - -;;******************************************************************************** -;; @function Read the last 3 bits after after timer 2 is up -;; @modifies: A -;; @details -;; - read shift register -;; - disable timer 2 interrupts -;; - enable shift register interrupts -;; - reset shift register -;;******************************************************************************** -.proc irq_timer_handler - lda kb::KB_IO + IO::SR - sta key_read + 1 - - lda kb::KB_IO + IO::T2CL ; clear interrupt flag - - ; disable timer interrupts - lda #(IO::IRQ::T2) - sta kb::KB_IO + IO::IER - ; enable shift register interrupts - lda #(IO::IRQ::IRQ | IO::IRQ::SR) - sta kb::KB_IO + IO::IER - ; reset SR - stz kb::KB_IO + IO::SR - - ; rotate bit 2 (last bit of keycode) into the carry - lda key_read+1 - ror - ror - ror - lda key_read ; not affecting carry - rol ; rotate carry into byte, rotate startbit into carry - ; TODO byte is inverted, maybe consider wasting 256 bytes for a bit reverse lookup table? - sta keycode - - stz key_read - stz key_read+1 - rts -.endproc