Apple-2-SW
/
prodos-drivers
mirror of https://github.com/a2stuff/prodos-drivers.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

ROMX: Update driver c/o Jeff Mazur 

This ensures all of page 2 is preserved for full compatibility.
This commit is contained in:
Joshua Bell 2022-06-02 22:14:48 -07:00
parent b1c3d52e0a
commit c323b205bc
1 changed files with 15 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
romx/romxrtc.system.s
View File

@ -1,10 +1,11 @@
;;; ROMX ProDOS RTC Driver
;;; Based on:
;;; * Ver 0.91
;;; * Ver 0.92 Added ZIP slowdowns - 11-Aug-2021 -
;;; Ver 0.91
;;; Ver 0.92 Added ZIP slowdowns
;;; Ver 0.93 Moved StubLoc to $0110
;;; Ver 0.94 Moved StubLoc to RTC_BUF + 7. Save/restore in stack
;;;
;;; Modifications by Joshua Bell inexorabletash@gmail.com
;;; * Converted to ca65 syntax and adapted to driver wrapper.
;;; * Driver core rewritten to ensure that $220 and up are saved/restored.
.setcpu "6502"
.linecont +
@ -171,17 +172,13 @@ loop: lda ClockDrv,y
;;; ROMX RTC driver - Relocated into ProDOS clock driver space
;;; ============================================================
;;; The first ~$20 bytes of $200 (input buffer) are safe to
;;; overwrite. They are also used by the built-in Thunderclock
;;; slot-clock driver in ProDOS ($200-$20C).
StubLoc := $0200 ; RAM stub for ROMX (<$20 bytes)
;;; ROMX Firmware writes RTC data into this fixed location.
;;; It risks conflicting with some applications (e.g. A2DeskTop),
;;; so the data is saved/restored around clock reads.
RTC_BUF := $02B0
RTC_BUF := $02B0 ; use keyboard buffer
StubLoc := RTC_BUF+7 ; RAM stub for ROMX
ClockDrv:
;; --------------------------------------------------
@ -193,12 +190,12 @@ ClockDrv:
;; --------------------------------------------------
;; Copy the stub to RAM, and preserve RTC_BUF
ldx #RamStubEnd-RamStub-1 ; copy stub to RAM
RELOC1 := *+1
: lda RamStub - ClockDrv,x ; self-modified during relocation
sta StubLoc,x
lda RTC_BUF,x ; save `RTC_BUF` too (way more than needed)
ldx #RamStubEnd-RamStub+7 ; preserve and copy stub to RAM
: lda RTC_BUF,x
pha
RELOC1 := *+1
lda RamStub-ClockDrv-7,x ; self-modified during relocation
sta RTC_BUF,x
dex
bpl :-
@ -215,7 +212,7 @@ bufloop:
lda RTC_BUF,y
RELOC2 := *+1
and MaskTable-1 - ClockDrv,y ; self-modified during relocation
and MaskTable-1-ClockDrv,y ; self-modified during relocation
;; BCD to Binary
;; On entry, A=BCD value &00-&99
@ -270,7 +267,7 @@ bufloop:
: pla
sta RTC_BUF,x
inx
cpx #RamStubEnd-RamStub
cpx #RamStubEnd-RamStub+7+1
bne :-
;; --------------------------------------------------