I’ve recently been looking at BASIC for Windows. What I wanted was something that captured the simplicity of CP/M or early MSDOS days, was small in size and had a reasonably useful set of functionality. TinyBASIC was a fairly good compromise but it lacked a few things … Continue reading BASIC1
Category Archives: articles
BASIC for Windows
One of the nice things about MSDOS/PCDOS computers and early Windows ones was they came with a BASIC interpreter. Now BASIC isn’t a language that people admit to using; but it is a fast way of exploring or demoing something. It is a pity that it vanished at some point. Continue reading BASIC for Windows
HP-29C Input Mode
When you press digits on the HP-29C, you go into “Input Mode”. What is that, and how does it work? Continue reading HP-29C Input Mode
HP-67 Program – Base Conversion
Do you frequently convert between number bases? I do and, whilst it’s getting pretty easy to do a lot in one’s head, there are times when it’d be nice to just type in a value and press “Convert”. Here’s a solution: Continue reading HP-67 Program – Base Conversion
HP-29C and s9
There are a series of “s flags” in the Woodstock (and Classic) series calculators. What they are used for, often varies according to the calculator model. While we were looking at prefixes, we saw what a number of the s flags do (s4,6,7,8,10) and saw a little bit about the s13 flag. We also saw the s9 flag but never even mentioned it. Here’s the detail Continue reading HP-29C and s9
HP-29C Prefix Keys
How does the HP-29C remember that you’ve pressed a prefix key? When you press f, g, or even STO or GTO; what happens next is not the normal key function. Continue reading HP-29C Prefix Keys
HP-29C Keypress Routine
So, you bought an old calculator; or a new one a very long time ago. You press a button and an answer pops out. How does it get from the first thing, to the second? This’ll answer the “getting from” part. I’ll leave the “getting to” part to later (get the HP-65 book if you’re not good at waiting). Here’s what happens … Continue reading HP-29C Keypress Routine
A Beepless HP-25
I had someone write to me about the calculator key clicks. Continue reading A Beepless HP-25
HP-55 Notes
Everything you didn’t want to know about a HP-55 … Continue reading HP-55 Notes
HP-55 Startup
Francois Roulet recently sent me a listing showing the startup sequence for the HP-55. It has a certain elegance to it and, as I believe Francois supports the sharing of knowledge, I’m including and discussing it here. Continue reading HP-55 Startup
HP-55 Emulator Bug
The HP-55 was before my time. I never had one, never considered one and never used one. However, it seems to be the immediate predecessor to the HP-25 and I wondered, “how did we get to this point?” so I looked.
The problem though is: the very few HP-55 emulators that I found, don’t work. I know I’ve said similar things before, but it was true then too. Here’s the problem Continue reading HP-55 Emulator Bug
The HP-25 ROM dilemma
Current thinking has the HP-25 and HP-25C having the same ROMs. After all, they do the same things. It makes a lot of sense.
This suggests that you can take an emulator that supports continuous memory and add in a standard HP-25 / HP-25C ROM. Whilst that does sound like a valid recipe for a HP-25C, it isn’t. There are some issues that may not have been mentioned before. Continue reading The HP-25 ROM dilemma
HP-25 – Full of Surprises
I’ve been ignoring the HP-25 for some time now, years really. Not because it didn’t deserve some attention but because it had plenty.
There are lots of emulators around for the HP-25. It was, rightly, a very popular calculator; and so it had lots and lots of emulators. Another one really wasn’t needed.
To misquote someone very badly, “Ask not what you can do for your country, ask instead what your calculator can do for you.” To my complete surprise, there are a lot of things in the HP-25 that don’t work the same as other calculators. Hidden within is a glimpse into the early development work for the entire series Continue reading HP-25 – Full of Surprises
HP-29 Microcode Reference
This is a bit early but I wanted to get a few things down now Continue reading HP-29 Microcode Reference
HP-21 Microcode Reference
This is a summary of what I’ve found. It is likely to get updated from time to time Continue reading HP-21 Microcode Reference
HP-21 DSP
This one should be remarkably straight forward; but it isn’t. There are standard ways of doing standard things. This is a standard thing. It just doesn’t follow any of the standard ways. Here’s what happens Continue reading HP-21 DSP
HP-21 Function Key
The HP-21 has a blue function key at the top right of the keyboard. I tend to think of it as the “g” key but that’s just my background with the HP-67 which has a blue “g” key. Whatever you call it, the question is, how does it work Continue reading HP-21 Function Key
HP-21 Low Power
Here’s what the HP-21 looks like with low power:
Here’s how that happens Continue reading HP-21 Low Power
HP-21 Keypress
The HP-21 keypress routine is incredibly simple. It looks like Continue reading HP-21 Keypress
HP-21 Scan Codes
Scanning the calculator keyboard to see if a key has been pressed, works pretty much the same on a HP-21 as all the other calculators. This is the process Continue reading HP-21 Scan Codes
