Comments on: Pi Day Rematch: Apple II vs. HP-41C

By: bdeckers

bdeckers — Mon, 05 Mar 2012 09:23:34 +0000

Hi,

I am selling on eBay “HP-41C Synthetic Programming Manual”, the original manual (Larken Publications-Oregon, 92 pages (letterformat), March 1982)
http://www.benl.ebay.be/itm/120871262164?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1558.l2649

I you are interested, could be an opportunity….

Thank you,

By: datajerk

datajerk — Sat, 05 Nov 2011 23:54:26 +0000

Yep. Now I really want to see your code.

By: datajerk

datajerk — Sat, 05 Nov 2011 23:54:05 +0000

Machine code. That’s hard core. :-)

Stomer’s Arc-tangent is a bit faster than Machin (http://sense.net/~egan/hpgcc/#Example:%20%20%CF%80%20Shootout).

If you still got your code, I’d really like to see it.

BTW, I am working on an article about the Apple II cassette tape. Hopefully I’ll be done in about a month.

By: Craig Peterson

Craig Peterson — Thu, 03 Nov 2011 18:46:15 +0000

PS – Using your ‘square of the ratios of the digits’ method, I would guess that the program above would have calculated the value of Pi to 1000 digits in about 2 minutes and 23 seconds. I’m sure I did some timings for this in 1980, but I can’t find any record of it. So machine code was faster than integer basic, but we all knew that anyway.

Craig Peterson

By: Craig Peterson

Craig Peterson — Thu, 03 Nov 2011 18:11:14 +0000

Just a quick note. Although the old Apple II (not Plus, not e, not c, not gs) was VERY limited in some ways, with an inexpensive 8 bit 6502 processor with a limited instruction set and a 1 mHz cpu clock speed, its real strength was that it finally gave the public nerds inside access to a computing machine, largely because of Steve Wozniak’s contributions, a hacker at heart. And they took off and ran with it, helping to start Apple into becoming the company that it is today.

I, too, was intrigued by Bob Bishop’s _Micro_ magazine article on calculating Pi. So much so that in 1980 I wrote a machine language program for my 48K Apple II that was able to calculate Pi to 36,364 digits in 52 hours, 28 minutes and 29 seconds. I was able to check the accuracy of my result by visiting the UCLA library and comparing the last few hundred digits in my result. I wrote it in machine code (no assembler), using Woz’s internal disassembler to check my work. I tried Gauss’ equation and Stirling’s equation, but I found Machin’s formula to be the fastest on my Apple II. I printed the result with a short AppleSoft program that ‘co-habitated’ memory with my machine code. A major issue in outputing 36,000+ on a 48K machine (minus room for the lower 2k+ used for the Applesoft program) is that you don’t have a lot of room for partial results as you complete the task, particularly when changing the binary to decimal for output. And the code was fully relocatable on this 8 bit processor. It was a fun challenge.

I actually submitted it to Apple as a lark program. It was submitted on the media of that time, a cassette tape. :-)

Craig Peterson
Apple II owner since 1978
(and Apple II Plus, Apple IIgs, Macintosh 128K, 512K, iMac, Mac LC, and PCs as well)

By: Mike Fikes

Mike Fikes — Fri, 22 Jul 2011 21:49:53 +0000

Interestingly, Glen Bredon’s assembly solution produces its result in 3:14.

By: datajerk

datajerk — Thu, 17 Mar 2011 19:10:08 +0000

35x faster on my 2.13GHz MacBook Air.

By: Pete Ashdown

Pete Ashdown — Thu, 17 Mar 2011 18:02:00 +0000

How long does it take the Apple ][ in emulation with the speed governor off? :)

By: Calibrator

Calibrator — Tue, 15 Mar 2011 20:52:46 +0000

If using a CPU accelerator is fair game one could use an 8 MHz “Zip Chip” for the Apple II.
This this a) 20 year old technology and b) should result in a speedup of 7 to 8 times regular CPU speed (slightly above 1 MHz on the Apple II).
24 minutes divided by 8 would give around 3 minutes, obviously…

By: hp lover

hp lover — Tue, 15 Mar 2011 15:08:03 +0000

Yep, no problem. Will do.

I do think the MCODE program had to have had some problems to run at 60% of the user code speed. That just can’t be right. :-)