Sharp EL-9300 Graphics Calculator, 296 bytes
This was my secondary school graphing calculator, getting on for 20 years ago! in the early '90s. I remember writing a mandelbrot generator for it way back then. And sure enough, its still sitting there in the NV memory:
ClrG
DispG
Range -2.35,2.35,.5,-1.55,1.55,0.5
y=-1.55
Label ly
x=-2.35
Label lx
n=1
zx=0
zy=0
Label ln
tzx=zx²-zy²+x
zy=(2*zx*zy)+y
zx=tzx
If zx²+zy²>4Goto esc
n=n+1
If n<20Goto ln
Label esc
If fpart (n/2)=0Goto npl
Plot x,y
Label npl
x=x+.05
If x<=2.35Goto lx
y=y+.05
If y<=1.55Goto ly
Wait
It took about 90 minutes to render. Only 20 iterations, but at this resolution it probably doesn't make much difference.
This is totally ungolfed. I'm sure I could save a bit of space, but I just wanted to share this historical curiosity!.
I love that the only control statements available are ifs and gotos.
Here's a photo. I don't have any other means to get the graphical output out:
