mirror of
https://github.com/catseye/SixtyPical.git
synced 2024-11-28 12:51:10 +00:00
55 lines
1.2 KiB
Plaintext
55 lines
1.2 KiB
Plaintext
// petulant.60p - The PETulant Cursor, a "display hack" for the Commodore 64
|
|
// Originally written by Chris Pressey sometime in the late 1980's
|
|
// Rewritten in P65 assembly and released March 2008
|
|
// Rewritten in SixtyPical in March 2018
|
|
// This work is part of the public domain.
|
|
|
|
// ----- Types -----
|
|
|
|
typedef routine
|
|
inputs border, blnon, color, background
|
|
outputs border
|
|
trashes a, z, n
|
|
irq_handler
|
|
|
|
// ----- Addresses -----
|
|
|
|
vector irq_handler cinv @ $314 // hw irq interrupt, 60x per second
|
|
|
|
byte blnon @ $cf // was last cursor blink on or off?
|
|
byte color @ $286 // current foreground colour for text
|
|
|
|
byte border @ $d020 // colour of border of the screen
|
|
byte background @ $d021 // colour of background of the screen
|
|
|
|
// ----- Variables -----
|
|
|
|
vector irq_handler save_cinv
|
|
|
|
// ----- Interrupt Handler -----
|
|
|
|
define our_cinv irq_handler
|
|
{
|
|
ld a, blnon
|
|
if not z {
|
|
ld a, color
|
|
} else {
|
|
ld a, background
|
|
}
|
|
st a, border
|
|
goto save_cinv
|
|
}
|
|
|
|
// ----- Main Program -----
|
|
|
|
define main routine
|
|
inputs cinv
|
|
outputs cinv, save_cinv
|
|
trashes a, n, z
|
|
{
|
|
with interrupts off {
|
|
copy cinv, save_cinv
|
|
copy our_cinv, cinv
|
|
}
|
|
}
|