fortran90语言程序设计进行《传热学》问题编程 急求~

fortran77程序，在fortran90上可正常调试运行：
dimension a0(7,8),a1(7,8)
do 10 i=1,7
a0(i,1)=200
a0(i,8)=50
a1(i,1)=200
a1(i,8)=50
10 continue

do 20 j=2,7
a0(1,j)=100
a0(7,j)=150
a1(1,j)=100
a1(7,j)=150
20 continue

k=100
n=0
do 30 i=2,6
do 30 j=2,7
a0(i,j)=125
30 continue

36 do 40 i=2,6
do 40 j=2,7
a1(i,j)=(a0(i-1,j)+a0(i+1,j)+a0(i,j-1)+a0(i,j+1))/4.0
40 continue
n=n+1
m=0
do 50 i=2,6
do 50 j=2,7
if (abs(a0(i,j)-a1(i,j)).gt.0.001) m=m+1
50 continue
if ((m.gt.0).and.(n.le.k)) then
do 60 i=2,6
do 60 j=2,7
a0(i,j)=a1(i,j)
60 continue
goto 36
endif

write(*,*) n,m
write(*,100)((a1(i,j),j=1,8),i=1,7)
100 format(1x,8f6.1)
stop
end

50 0
200.0 100.0 100.0 100.0 100.0 100.0 100.0 50.0
200.0 147.8 125.8 113.8 104.8 95.0 80.2 50.0
200.0 165.5 141.6 124.7 110.4 95.2 75.7 50.0
200.0 172.6 150.5 133.0 117.0 99.5 77.4 50.0
200.0 174.3 154.8 139.6 125.3 108.4 84.5 50.0
200.0 169.8 155.0 145.2 136.2 124.2 102.2 50.0
200.0 150.0 150.0 150.0 150.0 150.0 150.0 50.0
Stop - Program terminated.