I recently purchased a refurbished HP-85 from Larry Atherton. Here's what it looks like:
To say it's "spotless" is an understatement. Larry refinishes the case with epoxy paint, replaces the CRT, cleans the interior, and upgrades the cassette drive.
Even the bottom looks perfect. The rubber feet might not be precisely the right size, but they're brand new.
Included with the computer were 4 DC100 tapes: two with the HP Standard Pac and Math Pac, and two blanks.
The interior of the computer looks brand new. There is no dirt or dust anywhere. It even smells new.
Even the circuit boards appear to have been washed.
The printer belts are replaced, and the tape drive rebuilt as shown here:
The screen is razor sharp, especially considering it's a CRT and we're all used to flat panels now:
Graphics look nice, too, within the limited resolution available:
And the printer is fast, silent, and otherwise perfect:
Performance-wise: well, let's just say we've come a long way. Here's a simple BASIC program to find all the 3-digit numbers equal to the sum of the cubes of their digits:
10 OPTION BASE 0 @ DIM A(10)
20 FOR X = 0 TO 9 @ A(X) = X*X*X @ NEXT X
30 X = 100
40 FOR H = 1 TO 9 @ FOR T = 0 TO 9 @ FOR 0 = 0 TO 9
50 IF X = A(H) + A(T) + A(O) THEN DISP X
60 NEXT X
70 END
Bracketing this code with TIME statements reveals that it takes the 85 11.757 seconds to check the numbers 100 to 999. A similar algorithm in C executes in less than a millisecond on my desktop system.
Those sine curves in the graphics images? Just drawing a straight line on the screen from one corner to the other takes almost a second.
Still, there's something nostalgic and attractive about this computer. I love it.