What a find this was! I occasionally visit thrift stores and second-hand stores, looking for interesting calculators. The other day I had a very successful hunting trip: I returned home with an old scientific calculator (an APF Mark 50), a Casio FX-795P, and this rare Sharp PC-1450, all three machines in excellent working condition.

The PC-1450 is a BASIC programmable calculator. It shares a highly useful feature with the TI-74: it is a calculator mode, in which its buttons function much like the buttons on an ordinary scientific calculator. In other words, you can invoke functions that operate on the contents of the display register, as opposed to having to key in BASIC expressions in immediate mode. (As to why the designers of many newer calculators abandoned this calculator mode altogether, opting for the more cumbersome "formula display" mode of operation, I really have no idea.)

I have no manual for this beast, but I was able to discover a few things about its built-in BASIC interpreter anyway. For one thing, the PC-1450 BASIC has PEEK and POKE keywords, indicating the possibility of accessing the hardware or doing machine language programming. For another, the BASIC is fairly advanced and complete, it even contains the DATA statement, which I found is missing from the BASIC implementation on many a handheld device.

As usual, I wrote a Gamma function program to test the capabilities of this machine. In it, I made use of the DATA statement to simplify the program a little. Here's the result:

10:DATA 76.18009172,9.5E-9
20:DATA -86.50532032,-9.4E-9
30:DATA 24.01409824,8E-10
40:DATA -1.231739572,-4.5E-10
50:DATA 1.208650973E-3,8.7E-13
60:DATA -5.395239384E-6,-9.5E-16
100:INPUT "X=",X
110:T=1
120:IF X>=0 THEN 160
130:T=T*X
140:X=X+1
150: GOTO 120
160:G=1.9E-10+1
170:FOR I=1 TO 6
180:READ C,D
190:G=G+(C+D)/(X+I)
200:NEXT I
210:G=LN (SQR (2*π)*G/X)
220:G=G-X-5.5+LN (X+5.5)*(X+.5)
230:PRINT EXP(G)/T