[tex-k] Can't reproduce the illustrations on page 201 of The METAFONTbook

[胡亚捷 (Hu Yajie)]

I tried defining a new mode
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autorounding:=smoothing:=0;    % optional
mode_def medres = lowres_; pixels_per_inch:=600; enddef;
mode=medres; mode_setup;
u#:=10/18pt#; define_pixels(u);
beginchar(0,15u#,250/36pt#,70/36pt#);
pickup pencircle scaled (.4pt+blacker);
lft x1=round u-eps; x3=x1; x2=x4=w-x1;
y1=y2=good.y(.5[-d,h]+pt); y3=y4=h-d-y1;
draw z1--z2; draw z3--z4;
lft x6=round 3u; x7=w-x6;
x8=good.x .5w; x5-x6=x7-x8;
top y5=top y7=h+eps; bot y6=bot y8=-d-eps;
draw z5--z6; draw z7--z8;
tracingonline:=1; show currentpicture;
endchar;
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But I still got (MiKTeX and TeX Live 2017)
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row 57: 52+ 54- 33+ 35- |
row 56: 55- 51+ 36- 32+ |
row 55: 55- 51+ 36- 32+ |
row 54: 55- 51+ 36- 32+ |
row 53: 54- 50+ 35- 31+ |
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That is, the fourth row is the same as the second and third, not the fifth.
Do different machines produce different results?

By the way, you mentioned that the printed illustration has no `*****'
(five black pixels in a row) in the diagonal strokes. Yet mfbook.tex has
QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQPPQQQQQQQQQQQQQQQQQPPQQQQQQQQQQQQQQQ\cr
QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQPPPPQQQQQQQQQQQQQQQPPPPQQQQQQQQQQQQQQ\cr
QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQPPPPQQQQQQQQQQQQQQQPPPPQQQQQQQQQQQQQQ\cr
QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQPPPPPQQQQQQQQQQQQQQPPPPPQQQQQQQQQQQQQQ\cr
QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQPPPPQQQQQQQQQQQQQQQPPPPQQQQQQQQQQQQQQQ\cr
since line 11734...

If the printed illustration has no `*****' it's better to drop the issue.