DOS ain't dead

Hello,

recently a small bug was fixed in xcdrom32 that affected game "Tempest 2000":

https://github.com/Baron-von-Riedesel/Jemm/issues/44

The fix is rather trivial:


ReqMCS:
    call DoIOCmd        ;Issue "Test Unit Ready" command.
    mov edi,[AudAP]     ;Get media-change flag from table.
    mov al,[edi-1]
    mov [esi+1],al      ;Return media-change flag to user.
;--- v1.6: set audio status busy flag
;    ret
    jmp ReadAudioSt


Since xcdrom32 is based on one of J.R. Ellis' drivers (~ 20 years ago), those drivers may also benefit from a fix.

---
MS-DOS forever!

> Hello,
>
> recently a small bug was fixed in xcdrom32 that affected game "Tempest
> 2000":
>
> https://github.com/Baron-von-Riedesel/Jemm/issues/44
>
> The fix is rather trivial:
>
>
> ReqMCS:
> call DoIOCmd        ;Issue "Test Unit Ready" command.
> mov edi,[AudAP]     ;Get media-change flag from table.
> mov al,[edi-1]
> mov [esi+1],al      ;Return media-change flag to user.
> ;--- v1.6: set audio status busy flag
> ;    ret
> jmp ReadAudioSt
>
>
> Since xcdrom32 is based on one of J.R. Ellis' drivers (~ 20 years ago),
> those drivers may also benefit from a fix.

The latest FreeDOS package gathered by Mercury13 in 2021 indeed needs the fix:


;
; CD/DVD IOCTL Input "Media-Change Status" handler.
;
ReqMCS: call    DoCmd           ;Issue "Test Unit Ready" command.
        mov     di,[bx+AudAP-@] ;Get media-change flag from table.
        mov     al,cs:[di-1]
        mov     es:[si+1],al    ;Return media-change flag to user.
        ret                     ;Exit.


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FreeDOS / DOSEMU2 / ...