Re: [M100] In over my head? Or a Challenge!!
On 26/3/21 10:49 pm, Jeffrey Birt wrote: Most people use Isopropyl Alcohol (IPA) I tend to use denatured alcohol (methylated spirits) as I can get it locally and inexpensively. Each type works a little better as a solvent on different types of things. I did see it referred to as IPA, but I'm with Jonathan on this - I associate IPA with beer, which, given the context of using alcohol, was confusing. :) On an unrelated note, does anyone want to buy a beer soaked M100? (j/k). Cheers, --dt
Re: [M100] have O'scope loaner available to Brad Re: in over my head? Brad Grier
Wow, good thing I check my spam folder every so often -- this was in it!
Thanks for the kind offer Dale but I'm not local (Edmonton, AB, Canada).
Not a math major but will give that pi algo a try :D
On Wed, Mar 24, 2021 at 5:08 PM wrote:
> Brad & all,
> If you are in the Los Angeles, Calif area I could loan you a dual chan
> O'scope (20 or 30 MHz)
>
> I live in Torrance (SW of LA proper adjacent to Redondo & Hermosa Beach):
> dalescie...@aol.com
>
>
> For you PC-8201a owners here is a short 1 line pgm to iterate to 17
> significant digits of PI, in 25 mins 25sec for 4.9MHz clock.
>
> Why use 22/7 or 355/113 =6sd, 355/113# <8sd
>
> 4 powerCONT: defDBLd,i: Time$="00"::for J=2 to 46378 step4: i=J: d=d
> +4/(i*(i+1)*(i+2)) -4/((i+2)*(i+3)*i+4)): next:
> ?Time$" 3"chr$(27)d;(i-2)/4;:beep
>
> algorithm:
>
> pi = 3 +4/(2*3*4)-4/(4*5*6) +4/(6*7*8)-4/(8*9*10)repeat sequence
> until reach limit of 8201a double precision math routines
>
> =16 sig digits, squeezed out 17th by cutting iteration just before it
> breaks down - result begins slow downward plunge (decreases)
> (46378-2)/4 = 11594 actual iterationsAssumes 1st digit of PI is 3
>
> Result: 3.1415926535897932 (25 min, no spaces between pgm cmds) {does
> 12 sig digits in 3min}
>
> Any motivated Math majors able to design an algorithm that expands beyond
> 17sd independent of double prec assy lang limit?? :-)
>
> if there is interest, I could post more:
>
> 1..array of 17 for/next targets for each add'l digit displayed on separate
> lines in two columns taking up the whole display area.
> (displays time & expanding PI, current For/Next tgt) adds 25 sec for
> extra displays (25:50)
>
> 2. creative way to save same to a file, formatted as was displayed.
> (ordered: 1st - 8th, 2nd - 9th) in lieu of print screen to file!!! TBD
>
> Dale... K3MNN /6 since 1967 retired TRW Space & Electronics 2006
> Redondo Beach, Calif
>
--
--
Brad Grier
Re: [M100] In over my head? Or a Challenge!!
Most people use Isopropyl Alcohol (IPA) I tend to use denatured alcohol (methylated spirits) as I can get it locally and inexpensively. Each type works a little better as a solvent on different types of things. Jeff Birt -Original Message- From: M100 On Behalf Of Daryl Tester Sent: Thursday, March 25, 2021 8:39 PM To: m...@bitchin100.com Subject: Re: [M100] In over my head? Or a Challenge!! On 24/3/21 11:49 pm, Jeffrey Birt wrote: > I suspect it would work by itself, but it will take a lot of it. I > have used alcohol followed by a typical flux/PCB cleaner product which > works (to save on the more expensive flux cleaner). A transcontinental question - what type of alcohol are y'all talking about here - isopropyl or something else? Cheers, --dt
Re: [M100] In over my head? Or a Challenge!!
Hello, Where I am, IPA is something I generally get at a pub... When there were pubs open. Though I suspect it is isopropyl alcohol in this post Sorry, been isolated too long.. Jonathan Ursprungligt meddelande Från : b...@bradgrier.com Datum : 2021-03-26 - 02:50 (CEST) Till : m...@bitchin100.com Ämne : Re: [M100] In over my head? Or a Challenge!! I've got some glycerine on my grocery list now and I've got IPA, so flux removal is in the near future. It's a quiet night so I think I'm going to test your PCR again Jeff ; maybe I missed something. On Thu, Mar 25, 2021 at 7:39 PM Daryl Tester < dt-m...@handcraftedcomputers.com.au> wrote: On 24/3/21 11:49 pm, Jeffrey Birt wrote: > I suspect it would work by itself, but it will take a lot of it. I have used > alcohol > followed by a typical flux/PCB cleaner product which works (to save on the > more > expensive flux cleaner). A transcontinental question - what type of alcohol are y'all talking about here - isopropyl or something else? Cheers, --dt -- -- Brad Grier
