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Programming an HP-15C (2013)

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Re: Programming an HP-15C (2013)

#11

Post by mschaef »

drivers99 wrote: post #8

Wow that sounds a lot more complicated than the one I had, HP 42S, because you had to use codes for the instructions instead of just pulling up the instructions in readable ASCII. I found this random example of entering a program on a 42S: https://www.youtube.com/watch?v=JQMOOxup8bI Coincidentally, it even uses the FP (fractional part) and X=0? test that the OP mentioned. I wanted to see what programming the 15C look…

> Wow that sounds a lot more complicated than the one I had, HP 42S,

Yeah... the 42S derives from the earlier 41 series, and the 41 series was the first to use alphanumeric symbolic names for programming commands. Prior to that, there was always a very direct correlation between the button you pressed on the keyboard and the way the command was encoded in memory. (Which made sense given how resource limited the earlier calculators were.)

HP took this evolution one a step further with the HP28C, which was released a few years past the 41's. The 28C introduced a garbage collected heap and a tagged type representation for objects that gave you something essentially like a small RPN Lisp running on a handheld.

Re: Programming an HP-15C (2013)

#12

Post by GeorgeTirebiter »

gshubert17 wrote: post #7

I think the "someone who brought it back" is Swiss Micros, which makes a compatible calculator (which they call DM-15) as well as other models in the same family. They say their chip that emulates the original cpu is quite a bit faster than the original. https://www.swissmicros.com

I also want to mention the HP-45 iPad / iPhone app; it runs the exact microcode of the original on a VM. (My buddy was involved in this, and makes some $ - but I bought it and really really like it, and this isn't an ad, etc, etc.)

Re: Programming an HP-15C (2013)

#13

Post by mschaef »

GeorgeTirebiter wrote: post #12
gshubert17 wrote: post #7

I think the "someone who brought it back" is Swiss Micros, which makes a compatible calculator (which they call DM-15) as well as other models in the same family. They say their chip that emulates the original cpu is quite a bit faster than the original. https://www.swissmicros.com

I also want to mention the HP-45 iPad / iPhone app; it runs the exact microcode of the original on a VM. (My buddy was involved in this, and makes some $ - but I bought it and really really like it, and this isn't an ad, etc, etc.)

I have a 42S emulator running on my iPhone, but it really isn't the same as being able to press physical keys on a hardware device.

One of the charms of these devices was that they were built to last. ie: the keys were injection molded with two colors of plastic so they wouldn't wear down. So, while I still have a couple of working HP's from the 80's, I've been through a dozen or more mobile phones in about the same time...

Re: Programming an HP-15C (2013)

#15

Post by fmajid »

drivers99 wrote: post #8

Wow that sounds a lot more complicated than the one I had, HP 42S, because you had to use codes for the instructions instead of just pulling up the instructions in readable ASCII. I found this random example of entering a program on a 42S: https://www.youtube.com/watch?v=JQMOOxup8bI Coincidentally, it even uses the FP (fractional part) and X=0? test that the OP mentioned. I wanted to see what programming the 15C look…

I still have my original HP-15C from 1987, along with two SwissMicros DM-15L (I had also purchased the official HP reedition HP-15C LE, but one was stolen from work in a burglary, and I resold the other one at a tidy profit, the DM-15L is much better). I also have the official HP-15C iPhone app. And a HP-48GX, HP-33S, HP-35S, DM-42L.

To be frank, it's the only one of my HP calculators I can remember how to program, it's extremely simple, unlike newer models.

HP reedited the 15C manual for the limited edition:

http://www.hp.com/ctg/Manual/c03030589.pdf

Re: Programming an HP-15C (2013)

#16

Post by ghaff »

mschaef wrote: post #11
drivers99 wrote: post #8

Wow that sounds a lot more complicated than the one I had, HP 42S, because you had to use codes for the instructions instead of just pulling up the instructions in readable ASCII. I found this random example of entering a program on a 42S: https://www.youtube.com/watch?v=JQMOOxup8bI Coincidentally, it even uses the FP (fractional part) and X=0? test that the OP mentioned. I wanted to see what programming the 15C look…

> Wow that sounds a lot more complicated than the one I had, HP 42S, Yeah... the 42S derives from the earlier 41 series, and the 41 series was the first to use alphanumeric symbolic names for programming commands. Prior to that, there was always a very direct correlation between the button you pressed on the keyboard and the way the command was encoded in memory. (Which made sense given how resource limited the earli…

I used an HP41 for many years but it eventually died and I didn't really use an engineering calculator enough any longer to justify either repairing it or picking one up on eBay. I really liked the ergonomics and, although I have an emulator on my iPhone, it's not the same without the physical keys.

I did pick up a 28 at one point but never really bonded with it.

Re: Programming an HP-15C (2013)

#17

Post by fmajid »

mschaef wrote: post #13
GeorgeTirebiter wrote: post #12

Earlier quoted context omitted.

I also want to mention the HP-45 iPad / iPhone app; it runs the exact microcode of the original on a VM. (My buddy was involved in this, and makes some $ - but I bought it and really really like it, and this isn't an ad, etc, etc.)

I have a 42S emulator running on my iPhone, but it really isn't the same as being able to press physical keys on a hardware device. One of the charms of these devices was that they were built to last. ie: the keys were injection molded with two colors of plastic so they wouldn't wear down. So, while I still have a couple of working HP's from the 80's, I've been through a dozen or more mobile phones in about the same…

They're called doubleshot key caps. The better mechanical keyboards also use this method. The HP-15C and others in that line were exceptionally well made, with the PCB for the keyboard being ultrasonically welded for rigidity.

Re: Programming an HP-15C (2013)

#19

Post by mschaef »

ghaff wrote: post #16
mschaef wrote: post #11

Earlier quoted context omitted.

> Wow that sounds a lot more complicated than the one I had, HP 42S, Yeah... the 42S derives from the earlier 41 series, and the 41 series was the first to use alphanumeric symbolic names for programming commands. Prior to that, there was always a very direct correlation between the button you pressed on the keyboard and the way the command was encoded in memory. (Which made sense given how resource limited the earli…

I used an HP41 for many years but it eventually died and I didn't really use an engineering calculator enough any longer to justify either repairing it or picking one up on eBay. I really liked the ergonomics and, although I have an emulator on my iPhone, it's not the same without the physical keys. I did pick up a 28 at one point but never really bonded with it.

> I did pick up a 28 at one point but never really bonded with it.

IMO, the 28 and follow ons lost a lot of the focus of the earlier (more 'primitive') devices. They were more cumbersome to use, and whatever marginal improvement they offered in functionality didn't matter because everybody started to use PC's, laptops and the like.

Re: Programming an HP-15C (2013)

#20

Post by MegaDeKay »

GeorgeTirebiter wrote: post #10

I bought a 15C new. I still have it on my EE bench (replacing my slide rule, of course). Every 8 or 9 years I replace the three LR44 batteries. And writing little programs to tickle the Inner Nerd is always fun. HP: we miss you!

Mine was bought new well over 30 years ago. It is sitting on my desk within arms reach and I use it regularly. I have replaced the batteries two, maybe three times in all those years. The battery life of this thing is magical.
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