Threaded Mode | Linear Mode

**Katie Wasserman** · (This post was last modified: 07-07-2014 01:00 PM by Katie Wasserman.)

(07-06-2014 05:43 PM)Mike Morrow Wrote: I never owned any of the unfortunate clamshells except the HP 28C and HP 28S. These do not have RTCs. I never had much issue with their battery life, except for the battery door area breakage that occurred, especially in the S model, if batteries were left installed for a long time. :-)

The RTC in the 28C/28S is hidden. You need to do SYSEVAL to access it, but it's there and there have been many programs written that use it. Here's one, for example.

Tugdual · 07-06-2014, 08:20 PM

(07-06-2014 05:45 PM)Katie Wasserman Wrote:
(07-06-2014 05:18 PM)Tugdual Wrote: Also I read somewhere that unlike the 30b, the 15CLE cannot be flashed though it has the same connector.

What you read is absolutely wrong!

The 15CLE uses the same hardware as the 12C+ (also 12CAE) and they both flash just fine via the 6 point connection.

Thanks, you just restored some hope. So now we can also fully blame Hp for not moving a finger to get issues fixed.

Mike Morrow · 07-07-2014, 04:28 AM

(07-06-2014 05:52 PM)Katie Wasserman Wrote: The RTC in the 28C/28S is hidden. You need to do SYSEVEL to access it, but it's there and there have been many programs written that use it. Here's one, for example.

Thanks much for that information, Katie. This is the first I've heard of an RTC in the HP 28 series, even though I purchased my HP 28C 28 years ago. One must wonder why the RTC was not made an explicit user function...maybe it's like the RTC in the HP 38gii...its firmware does not present it to the user. The HP 42S is similar...RTC in hardware but not presented to the user...in contrast to the HP 17Bi. Perhaps the real problem was not enough ROM to implement in the 42S or 28C/S.

I never warmed up to the 28-series nor spent much time with mine, nor any later RPL machines until the HP 50G appeared (albeit with its somewhat buggy RTC functions).

Thomas Radtke · 07-07-2014, 07:30 AM

(07-06-2014 08:20 PM)Tugdual Wrote: Thanks, you just restored some hope.

IIRC, there's an update to the 30b that's not available to the public. I *know* there's an update to another calculator sharing the same fate. I have no hope for the 15C LE as it is not even in production anymore.

(07-06-2014 08:20 PM)Tugdual Wrote: So now we can also fully blame Hp for not moving a finger to get issues fixed.

If it makes you feel better ... ;-(

ElectroDuende · 10-01-2014, 01:52 PM

(07-06-2014 04:27 PM)Katie Wasserman Wrote: I agree, this, the PSE (pause) problem and the possibility of corrupting memory when the old self-tests are run are the biggest issues with 15CLE. It sure would be nice to have new firmware available for download.

I learnt yesterday about the memory corruption using the old tests... in the hard way!
I've just searched the forum now to confirm it.

:-(

brouhaha · 10-05-2014, 03:57 AM

(07-07-2014 04:28 AM)Mike Morrow Wrote: One must wonder why the RTC was not made an explicit user function...

"Life is short and ROM is full." -- Dr. William C. WIckes, one of the inventors of RPL

Paul Dale · 10-05-2014, 04:34 AM

(10-05-2014 03:57 AM)brouhaha Wrote: "Life is short and ROM is full." -- Dr. William C. WIckes, one of the inventors of RPL

Don't I know this. Oh for more flash on the 34S Smile

- Pauli

robert rozee · 10-06-2014, 06:44 AM

(10-05-2014 04:34 AM)Paul Dale Wrote: Don't I know this. Oh for more flash on the 34S

- Pauli

am i right in saying that many people have opened up their 34S to add a crystal for improved timing accuracy? and looking at the internal photos (as i recall) there does seem to be an empty SO-8 footprint(s) on the PCB - perhaps intended to accommodate and 8-pin EEPROM?

widespread willingness to add crystal + available footprint (or other connection points) for an EEPROM = possibility to add auxiliary flash memory.

are my calculations correct?

cheers,
rob :-)

Paul Dale · 10-06-2014, 07:39 AM

(10-06-2014 06:44 AM)robert rozee Wrote: there does seem to be an empty SO-8 footprint(s) on the PCB - perhaps intended to accommodate and 8-pin EEPROM?

Unfortunately, no. There is an exposed SPI bus which we could use for extra storage space. How would one program it? What would the performance be like?

We've hit the limits of the 30B hardware very hard. We're out of flash, non-volatile RAM and volatile RAM. Marcus managed to find 55 bytes of semi-non-volatile RAM in the LCD driver by not having a blinking cursor. This is completely used. We really are down to a couple of *bits* of RAM left. Flash is completely full. We've pushed this one pretty much as far as possible.

Walter will willingly inform anyone as to how awesome and complete the 30B display is Smile

Pauli

walter b · 10-06-2014, 08:27 AM

(10-06-2014 07:39 AM)Paul Dale Wrote: Walter will willingly inform anyone as to how awesome and complete the 30B display is

We all know Smile

One big reason why we're longing for a 43S.

d:-)

robert rozee · 10-06-2014, 09:30 AM

(10-06-2014 07:39 AM)Paul Dale Wrote: There is an exposed SPI bus which we could use for extra storage space. How would one program it? What would the performance be like?

Pauli

the performance would be mediocre at best, but then that is one of the trade-offs. i'd envision any such storage being used for infrequently used code written in the high-level "calculator language", that could be swapped into ram when required.

or it could be used just to hold user programs. this is what the MicroMite does - a single-chip basic interpreter that runs basic programs from flash.

but then, as others have noted, with the 30B being retired the future is rather limited.

btw, i am surprised that the 43S has such a long lead. it seems that with a 32MX795 and a few wires (quite literally) one could have hardware running within a few weeks. 512k flash, 128k ram, 2.3v to 3.6v (4.0v max) power supply range.

rob :-)

brouhaha · 10-06-2014, 10:10 AM

(10-06-2014 09:30 AM)robert rozee Wrote: btw, i am surprised that the 43S has such a long lead. it seems that with a 32MX795 and a few wires (quite literally) one could have hardware running within a few weeks. 512k flash, 128k ram, 2.3v to 3.6v (4.0v max) power supply range.

By all means, go for it!

As I recall, we had what's now called the XC-42 hardware "running within a few weeks".

I think it's time to finally reveal our formerly super-secret business plan to make a fortune selling calculators:

Design calculator hardware
Build calculator hardware
???
Profit!

We're currently working on step 3, but I'm confident that we'll have it licked Real Soon Now.

walter b · 10-06-2014, 10:19 AM

(10-06-2014 10:10 AM)brouhaha Wrote: I think it's time to finally reveal our formerly super-secret business plan to make a fortune selling calculators:

Design calculator hardware

Build calculator hardware

???

Profit!

We're currently working on step 3, but I'm confident that we'll have it licked Real Soon Now.

axd1967 · (This post was last modified: 10-01-2015 08:55 AM by axd1967.)

(07-04-2014 06:38 PM)Tugdual Wrote: - the original 15C keyboard is probably made of rubber or something that became extremely stiff and I can't really use it without pressing very hard on key with the risk to deteriorate it. Wonder if there is a way to fix that BTW...

Interesting: are there more people having this issue, or references to it?

brickviking · 10-01-2015, 10:48 PM

(10-06-2014 09:30 AM)robert rozee Wrote: …
btw, i am surprised that the 43S has such a long lead. it seems that with a 32MX795 and a few wires (quite literally) one could have hardware running within a few weeks.
…

rob :-)

I'm after an emulator for the 43S, as I've been collecting those. I seem to have far more emulators than I do real calculators.

(Post 1 SL 5)

Marcio · 01-12-2016, 08:56 PM

(10-01-2015 08:55 AM)axd1967 Wrote:
(07-04-2014 06:38 PM)Tugdual Wrote: - the original 15C keyboard is probably made of rubber or something that became extremely stiff and I can't really use it without pressing very hard on key with the risk to deteriorate it. Wonder if there is a way to fix that BTW...

Interesting: are there more people having this issue, or references to it?

I bought 2 15C's last year. The first one was a tad bitten up and the keys were a joy to press. Eventually I sold it and bought the second one, which looks like new but the keys are not as soft. So maybe this has to do with use?

David Hayden · 01-12-2016, 10:45 PM

(10-06-2014 10:10 AM)brouhaha Wrote: I think it's time to finally reveal our formerly super-secret business plan to make a fortune selling calculators:

Design calculator hardware

Build calculator hardware

???

Profit!

We're currently working on step 3, but I'm confident that we'll have it licked Real Soon Now.

I've seen much worse business plans than this. Smile

BillCRAV · 03-13-2016, 01:17 PM

(07-05-2014 03:52 PM)Katie Wasserman Wrote: {snip} The Voyagers used SOS (Silicon on Sapphire) CMOS technology that HP had developed just a couple of years earlier. {snip}

If you are referring to the RCA 1802 chip, that is incorrect.

Members of the Yahoo COSMAC ELF group have verified that ONLY the Galileo spacecraft used the 1802.
Neither Pioneer, Viking, Voyager, nor any other spacecraft, used the 1802.
(the Space Shuttle MIGHT have used one in one of its systems)
There are a few Earth-orbiting satellites that used the 1802. (OSCAR?, ...)

Dave Frederickson · (This post was last modified: 03-13-2016 03:08 PM by Dave Frederickson.)

(03-13-2016 01:17 PM)BillCRAV Wrote:
(07-05-2014 03:52 PM)Katie Wasserman Wrote: {snip} The Voyagers used SOS (Silicon on Sapphire) CMOS technology that HP had developed just a couple of years earlier. {snip}

If you are referring to the RCA 1802 chip, that is incorrect.

Members of the Yahoo COSMAC ELF group have verified that ONLY the Galileo spacecraft used the 1802.
Neither Pioneer, Viking, Voyager, nor any other spacecraft, used the 1802.
(the Space Shuttle MIGHT have used one in one of its systems)
There are a few Earth-orbiting satellites that used the 1802. (OSCAR?, ...)

I believe Katie was referring to the Voyager calculator series, not the space probes.

**Katie Wasserman** · 03-13-2016, 03:53 PM

(03-13-2016 03:07 PM)Dave Frederickson Wrote:
(03-13-2016 01:17 PM)BillCRAV Wrote: If you are referring to the RCA 1802 chip, that is incorrect.

Members of the Yahoo COSMAC ELF group have verified that ONLY the Galileo spacecraft used the 1802.
Neither Pioneer, Viking, Voyager, nor any other spacecraft, used the 1802.
(the Space Shuttle MIGHT have used one in one of its systems)
There are a few Earth-orbiting satellites that used the 1802. (OSCAR?, ...)

I believe Katie was referring to the Voyager calculator series, not the space probes.

Of course! This is an HP calculator forum after all, so the context is implied.