習作。 マークダウンにF#ってないのな。
module hoge
// プログラムカウンター=r7
let r = [| 0; 0; 0; 0; 0; 0; 0; 0 |]
let main file =
let aout = System.IO.File.ReadAllBytes file
let read16 (a:byte[]) b =
(int a.[b]) ||| ((int a.[b+1]) <<< 8)
let write16 (a:byte[]) b c =
a.[b] <- byte c
a.[b + 1] <- byte (c >>> 8)
let tsize = read16 aout 2
let dsize = read16 aout 4
let mem = aout.[16 .. 16 + tsize + dsize - 1]
let fetch() =
let ret = read16 mem r.[7]
r.[7] <- r.[7] + 2
ret
let mutable running = true
// dd書き込み w order
let mov27 w =
let t = ((w >>> 3) &&& 7)
let rn = w &&& 7
if rn = 7 then
match t with
| 6 ->
let w1 = fetch()
let w2 = fetch()
write16 mem (r.[7] + w2) w1
| _ -> printfn "??"
else
match t with
| 0 ->
let w1 = fetch()
r.[rn] <- w1
| 1 ->
let w1 = fetch()
write16 mem r.[rn] w1
| 6 ->
let w1 = fetch()
let w2 = fetch()
write16 mem (r.[rn] + w2) w1
| _ -> printfn "??"
// dd書き込み w order v fetch
let mov w =
let t1 = ((w >>> 9) &&& 7)
let rn1 = ((w >>> 6) &&& 7)
let t2 = ((w >>> 3) &&& 7)
let rn2 = w &&& 7
match t1 with
| 0 ->
match t2 with
| 1 ->
write16 mem r.[rn2] r.[rn1]
| 2 ->
let v = fetch()
write16 mem (r.[rn2] + v) r.[rn1]
| 6 ->
let v = fetch()
write16 mem (r.[rn2] + v) r.[rn1]
| _ -> printfn "??"
| 2 ->
if rn1 = 7 then
mov27 w
else
match t2 with
| 6 ->
let v = fetch()
r.[rn2] <- read16 mem v
| _ -> printfn "??"
| _ -> printfn "??"
// dd書き込み w order
let movb27 w =
let t = ((w >>> 3) &&& 7)
let rn = w &&& 7
if rn = 7 then
match t with
| 6 ->
let w1 = fetch()
let w2 = fetch()
mem.[r.[1] + w2] <- byte w1
| _ -> printfn "??"
else
match t with
| 1 ->
let w1 = fetch()
mem.[r.[rn]] <- byte w1
| 6 ->
let w1 = fetch()
let w2 = fetch()
mem.[r.[rn] + w2] <- byte w1
| _ -> printfn "??"
// dd書き込み w order v fetch
let movb w =
let t1 = ((w >>> 9) &&& 7)
let rn1 = ((w >>> 6) &&& 7)
let t2 = ((w >>> 3) &&& 7)
let rn2 = w &&& 7
match t1 with
| 0 ->
match t2 with
| 1 ->
mem.[r.[rn2]] <- byte r.[rn1]
| 6 ->
mem.[r.[rn2] + fetch()] <- byte r.[rn1]
| _ -> printfn "??"
| 2 ->
if rn1 = 7 then
movb27 w
else
printfn "??"
| _ -> printfn "??"
let swab w =
let t = ((w >>> 3) &&& 7)
let rn = w &&& 7
match t with
| 0 ->
r.[rn] <- ((r.[rn] &&& 0xff) <<< 8) ||| ((r.[rn] &&& 0xff00) >>> 8)
| _ -> printfn "??"
let sub27 w =
let t = ((w >>> 3) &&& 7)
let rn = w &&& 7
if rn = 7 then
match t with
| 6 ->
let w1 = fetch()
let w2 = fetch()
let addr = r.[7] + w2
write16 mem addr ((read16 mem addr) - (w1))
| _ -> printfn "??"
else
match t with
| _ -> printfn "??"
// dd書き込み w order v fetch
let sub w =
let t1 = ((w >>> 9) &&& 7)
let rn1 = ((w >>> 6) &&& 7)
let t2 = ((w >>> 3) &&& 7)
let rn2 = w &&& 7
match t1 with
| 2 ->
if rn1 = 7 then
sub27 w
else
printfn "??"
| _ -> printfn "??"
while running && r.[7] < tsize do
match fetch() with
// mutableを付けない変数は中身が変わらないので、ビットシフト演算しても中身は変わらない
| w when (w >>> 12 = 0o01) -> mov w
| w when (w >>> 12 = 0o11) -> movb w
| w when (w >>> 12 = 0o16) -> sub w
| w when (w >>> 12 = 0o00) -> swab w
// sys 1 ; exit
| 0o104401 ->
// exit r.[0]
running <- false
// sys 4 ; write
| 0o104404 ->
let arg1 = fetch()
let arg2 = fetch()
let bytes = mem.[arg1 .. arg1 + arg2 - 1]
printf "%s" (System.Text.Encoding.ASCII.GetString bytes)
| w ->
printfn "%04x: %04x ???" r.[7] w
running <- false
