Post Reply 
Benchmarks 71B versus 48GX
05-02-2014, 09:23 PM
Post: #1
Benchmarks 71B versus 48GX
Does anyone have a raw chip speed comparison between the 71B and the 48GX?
Find all posts by this user
Quote this message in a reply
05-03-2014, 01:48 AM
Post: #2
RE: Benchmarks 71B versus 48GX
Quote:Does anyone have a raw chip speed comparison between the 71B and the 48GX?

Somehow I recall the 71 CPU to be on the order of 600KHz whereby the 28C was 1 MHz, the 28S was 2 MHz and the 48SX and GX were 4 MHz. Hopefully, I didn't mess that up :-)

Jake
Find all posts by this user
Quote this message in a reply
05-03-2014, 01:57 AM
Post: #3
RE: Benchmarks 71B versus 48GX
(05-02-2014 09:23 PM)John W Kercheval Wrote:  Does anyone have a raw chip speed comparison between the 71B and the 48GX?

From Craig Finseth's invaluable HPDATAbase:

HP-71
Saturn, 4-bit, 640 KHz 1LK7 5 V CMOSC

HP-28C
1LK7 Saturn CPU (1 MHz)

HP-28S
Lewis, 1 MHz

HP-48SX
Clarke (147 pin TAB), 2 MHz

HP-48GX
Yorke (00048-80063, 160 pin QFP), 4 MHz

Mark Hardman

Ceci n'est pas une signature.
Find all posts by this user
Quote this message in a reply
05-03-2014, 12:37 PM
Post: #4
RE: Benchmarks 71B versus 48GX
Thanks the 48GX is a 4 bit machine correct?
Find all posts by this user
Quote this message in a reply
05-03-2014, 03:22 PM
Post: #5
RE: Benchmarks 71B versus 48GX
(05-03-2014 12:37 PM)John W Kercheval Wrote:  Thanks the 48GX is a 4 bit machine correct?

Yes. The Clarke and Yorke chips were four bits (nibble) with a 20 bit maximum address.

Mark Hardman

Ceci n'est pas une signature.
Find all posts by this user
Quote this message in a reply
05-04-2014, 10:56 PM
Post: #6
RE: Benchmarks 71B versus 48GX
(05-03-2014 01:57 AM)Mark Hardman Wrote:  HP-28C
1LK7 Saturn CPU (1 MHz)

Sorry, this is wrong. The HP-28C use the same LC frequency generator like in the HP-71B, so the CPU strobe frequency is 600-650 KHz. You can peek the 5 nibble =CSPEED content (#4F00Fh) on a HP-28C with an external peek program. The 5 nibble content is the CPU strobe frequency divided by 16. So a content of #09C05h mean: #09C05h -> #39941d * 16 = #639056d -> ~640 KHz.

(05-03-2014 01:57 AM)Mark Hardman Wrote:  HP-48GX
Yorke (00048-80063, 160 pin QFP), 4 MHz

This is also a mistake. Only very early HP48G Series calculators had a strobe frequency of 4 MHz. The frequency was then reduced to a nominal speed of ~3.68 MHz.
Visit this user's website Find all posts by this user
Quote this message in a reply
05-05-2014, 12:02 AM
Post: #7
RE: Benchmarks 71B versus 48GX
(05-04-2014 10:56 PM)Christoph Giesselink Wrote:  
(05-03-2014 01:57 AM)Mark Hardman Wrote:  HP-28C
1LK7 Saturn CPU (1 MHz)

Sorry, this is wrong.

(05-03-2014 01:57 AM)Mark Hardman Wrote:  HP-48GX
Yorke (00048-80063, 160 pin QFP), 4 MHz

This is also a mistake.

I will pass the corrections back to Craig.

Mark Hardman

Ceci n'est pas une signature.
Find all posts by this user
Quote this message in a reply
05-05-2014, 12:12 AM (This post was last modified: 05-05-2014 06:35 AM by Didier Lachieze.)
Post: #8
RE: Benchmarks 71B versus 48GX
(05-04-2014 10:56 PM)Christoph Giesselink Wrote:  
(05-03-2014 01:57 AM)Mark Hardman Wrote:  HP-48GX
Yorke (00048-80063, 160 pin QFP), 4 MHz

This is also a mistake. Only very early HP48G Series calculators had a strobe frequency of 4 MHz. The frequency was then reduced to a nominal speed of ~3.68 MHz.

For reference, on my 48GX SN 3443S in the interactive self-test (ON-D) test [A] returns a speed of ~3.93 MHz. (Exit of the self-test is done by ON-C)
Find all posts by this user
Quote this message in a reply
05-05-2014, 11:23 AM
Post: #9
RE: Benchmarks 71B versus 48GX
Ok I tried that test is it holding down the D key while starting it? It does not seem to do anything. How do you do the tests?
Find all posts by this user
Quote this message in a reply
05-05-2014, 11:43 AM
Post: #10
RE: Benchmarks 71B versus 48GX
(05-05-2014 11:23 AM)John W Kercheval Wrote:  Ok I tried that test is it holding down the D key while starting it? It does not seem to do anything. How do you do the tests?

With the 48 already ON - press ON and D simultaneously, for more details see the HP48 FAQ section 4.7 What are the different interactive self-tests?
Find all posts by this user
Quote this message in a reply
05-05-2014, 12:00 PM
Post: #11
RE: Benchmarks 71B versus 48GX
(05-05-2014 12:12 AM)Didier Lachieze Wrote:  
(05-04-2014 10:56 PM)Christoph Giesselink Wrote:  This is also a mistake. Only very early HP48G Series calculators had a strobe frequency of 4 MHz. The frequency was then reduced to a nominal speed of ~3.68 MHz.

For reference, on my 48GX SN 3443S in the interactive self-test (ON-D) test [A] returns a speed of ~3.93 MHz. (Exit of the self-test is done by ON-C)
Funny enough I was reading somewhere the other day(that seemed fairly reliable) that when the 48G series came out that they were having 4MHz yield problems -> binning. The Xs got the 4MHz "good" chips and the other got the not quite able to make 4MHz chips... (c. 3.5-7MHz IIRC)
Find all posts by this user
Quote this message in a reply
05-05-2014, 01:34 PM
Post: #12
RE: Benchmarks 71B versus 48GX
Ok got it.

How do we speed it up? What if we overclock it to 8MHZ for example?

Let's talk HP48GX hardware mods!
Find all posts by this user
Quote this message in a reply
05-05-2014, 01:42 PM
Post: #13
RE: Benchmarks 71B versus 48GX
Probably better to overclock a 50g. They're still making them, and supposedly they are underclocked as it is.

It ain't OVER 'till it's 2 PICK
Find all posts by this user
Quote this message in a reply
05-05-2014, 02:20 PM
Post: #14
RE: Benchmarks 71B versus 48GX
(05-05-2014 01:34 PM)John W Kercheval Wrote:  Ok got it.

What speed do you get?

(05-05-2014 01:34 PM)John W Kercheval Wrote:  How do we speed it up? What if we overclock it to 8MHZ for example?

Let's talk HP48GX hardware mods!

This has been done back in the 90's, the performance increase seems to be limited to 30-50% with some side effects: Digitalis Speed UP for HP48G/GX/G+.
See also this post on comp.sys.hp48: Overclocking the HP.
Find all posts by this user
Quote this message in a reply
05-05-2014, 05:10 PM
Post: #15
RE: Benchmarks 71B versus 48GX
I get 3.775024
Find all posts by this user
Quote this message in a reply
Post Reply 




User(s) browsing this thread: 1 Guest(s)