Here's a snippet I found which shows orthogonal projection:
sync on
sync rate 80
ortho = 361.45
perp = 61.962
load image "castle02.bmp", 1
make matrix 1, 100, 100, 10, 10
prepare matrix texture 1, 1, 1, 1
randomize matrix 1,100
fill matrix 1,0.0, 1
update matrix 1
make object sphere 1, 4
texture object 1, 1
position object 1, 30, 2, 30
make object sphere 2, 8
texture object 2, 1
position object 2, 50, 4, 50
global x#, y#, z#
y# = 100
do
if upkey() = 1 then z# = z# + 2
if downkey() = 1 then z# = z# - 2
if rightkey() = 1 then x# = x# + 2
if leftkey() = 1 then x# = x# - 2
position camera x#, y#, z#
point camera x#, 0, z#
if inkey$() = "o"
set camera fov ortho
y# = 3000
endif
if inkey$() = "p"
set camera fov perp
y# = 100
endif
sync
loop c:/dos
c:/dos run
run dos run
