20
Jan
'17

Windows30

I installed Windows 3.0 for the first time today* From seven 720 kilobyte stiffy** disks. And it worked first time.

 

* Windows 3.1, I’ve installed countless times. Windows 3.0, never.

** Yea that’s what we call them here.








28
Feb
'16


Do go read

 





16
Feb
'16

PM2421-cropped

Mahala gratis verniet and for free, nogal.

And it seems to work, that’s indeed a 4.7k resistor.

Look at the ridiculous scale on this thing — not only uA but nA as well. Why would I want to measure a nano-amp?

I think this will become part of my permanent test setup.





Lindgren liked to sit on the small second-floor balcony with a view of the sea. There is a bench in a corner of the balcony. Karin Nyman, Lindgren’s daughter, who is now over 80 and closely resembles her mother, says: “Take a look under the bench.”

It’s easier said than done. Dates, a few words and many stenographic symbols are written in pencil on the underside of the bench: “July 3, 1963. Summer. Radiant. Like in the good old days. The early summer was magical. I was here all of June and wrote “Michel from Lönneberga.” The book is now finished. We bought a sailboat, the ‘Saltkrokan.'” Lindgren must have laid flat on her back to write these words, with her feet sticking out from underneath the bench. Perhaps she even wiggled her toes, just like Pippi.

Read the whole article here.





Early eighties, to be more precise.

You see, there was Apple DOS (Disk Operating System). And then there were other Disk Operating Systems, faster and therefore better (OK, faster because very often they left out a whole lot of error checking that the Apple DOS performed — but if you have an error there’s not much you can do about it so why check :-)

One of these was Diversi-DOS. It had a splash screen, which of course was stored on the disk, along with display code.

So of course I promptly hacked the splash screen to display my own message. Recently came across a printout from way back then. So here we have some of the first machine code I ever wrote.

086C-   20 2F FB    JSR   $FB2F       JSR $FB2F and $FC58 clears the High-Res and normal text screens.
086F-   20 58 FC    JSR   $FC58
0872-   A0 00       LDY   #$00
0874-   B9 A2 08    LDA   $08A2,Y     Y=0, load from $08A2 (it's down there, 8D 8D 8D etc)
0877-   F0 07       BEQ   $0880       If the value you've loaded is zero, go to $0880 ($00 marks the end)
0879-   20 ED FD    JSR   $FDED       Otherwise print the character ($FDED prints the accumulator A), increment Y
087C-   C8          INY
087D-   4C 74 08    JMP   $0874       And get the next character
0880-   A0 04       LDY   #$04        Now, load Y with 4 and jump to the subroutine at $0895, below.
0882-   20 95 08    JSR   $0895
0885-   C8          INY
0886-   C0 20       CPY   #$20
0888-   D0 F8       BNE   $0882       Then, increment Y and loop, stop when Y reaches $20 (32 -- $ indicates base 16)
088A-   20 95 08    JSR   $0895
088D-   88          DEY               Now do the same thing, but from $20 down to 4.
088E-   C0 04       CPY   #$04
0890-   D0 F8       BNE   $088A
0892-   4C FD 08    JMP   $08FD       And then exit (back to Diversi-DOS)

                                      So here we are with Y=4..31, then 32..5
0895-   98          TYA               Move Y to X via A (because this is how a 6502 works) Second TYA maybe a bug*
0896-   AA          TAX
0897-   98          TYA
0898-   8D 30 C0    STA   $C030       Click the speaker by accessing $C030 (yes, one bit, on or off, no Soundblaster)
089B-   20 A8 FC    JSR   $FCA8       $FCA8 delays for some time dependent on the value in A
089E-   CA          DEX               Now decrement X and loop, i.e. do this as many times as the value in Y
089F-   D0 F6       BNE   $0897
08A1-   60          RTS               And return
08A2-   8D 8D 8D    STA   $8D8D       This is the text that gets displayed by the code up there from $872 to $87E
08A5-   8D 8D 8D    STA   $8D8D       Says "COPIED BY THE DIRTY DEVIL"** in the middle(-ish) of the 40 x 24 screen
08A8-   8D 8D 8D    STA   $8D8D
08AB-   8D 8D 8D    STA   $8D8D
08AE-   A0 A0       LDY   #$A0        $A0 = Spaces
08B0-   A0 A0       LDY   #$A0
08B2-   A0 A0       LDY   #$A0
08B4-   C3          ???               $C3 = C, $CF = O and so on.
08B5-   CF          ???
08B6-   D0 C9       BNE   $0881
08B8-   C5 C4       CMP   $C4
08BA-   A0 C2       LDY   #$C2
08BC-   D9 A0 D4    CMP   $D4A0,Y
08BF-   C8          INY
08C0-   C5 A0       CMP   $A0
08C2-   C4 C9       CPY   $C9
08C4-   D2          ???
08C5-   D4          ???
08C6-   D9 A0 C4    CMP   $C4A0,Y
08C9-   C5 D6       CMP   $D6
08CB-   C9 CC       CMP   #$CC
08CD-   00          BRK

* As I said, the second TYA is not needed, TAX doesn’t change A. But it’s from the earlier code, which didn’t vary the time of each “note”.

** Which is what I called myself waybackwhen.

The result is a sliding note that slows down as it gets lower, then speeds up again. At full volume (erm, there only was one volume) it’s guaranteed to get attention. Of course some guys were much much more into this than I was.

Stay tuned (might take a few years) for when I blog about the digitized voice I once hacked into the Diversi-DOS startup screen… yes, you can recognizably digitize a voice using only one bit.

 





22
Mar
'15

Today, seventeen years ago, we re-entered South Africa from Lesotho as part of the 50th Anniversary Tour of South Africa. All through 1996/1997 I’d been frantically putting a Land-Rover together, with much accelerated effort towards the end (if it wasn’t for the last moment I’d never get anything done).

With help from my brother, we ended up getting the Rand-Lover through roadworthy at the end of February 1998, and Elmari and I left on the trip on the 6th of March. It was a bit… frantic.

Since then, this mysterious package has been kicking ’round the back of the Rand-Lover.

Look, it’s wrapped in period-authentic newspaper.

But what can it be?

Look! It’s the trim…

…that goes on the back doors, here.

The intention was to fit these somewhere on the trip. A lot of things did get fitted, but the trim did not make the list.

Yesterday, Eskom blessed us with some more electricity rationing. There’s a round ‘tuit for me! Yay!

I used these captive nuts and M5 machine screws.

And there you go (actually it was a lot more finicky than it looks).

The colour mismatch is 17 years’ worth of fade on the door. Not too bad, actually.

I decided to leave the nearside door for another 17 yea… nah, kidding, I did both.

 





We have at least one copy of everything Sir Pterry ever wrote. At least one, because both Tanya and I were fans long before we met, and the libraries merged.

I discovered Discworld when The Colour of Magic hit paperback, back in ’85 or so. Been hooked since. Re-read the whole thing recently, it’s so obvious that while the author really wants to write parody, the Discworld keeps forcing him back into Being Serious.  And that’s the thing. While Discworld is light-hearted, the issues are serious. You can read right over all of that without skipping a beat, or you can take your time and realise that real issues are being addressed.

*Sigh* I guess we sort of expected him to be Cohen the Barbarian, so adept at surviving that nothing can kill him.

Alas.





Ah yes, New Years’ resolutions. Gotta love ’em.

However, I have too much stuff. There. I said it. I mean, I firmly believe in the William Morris quote,  however, times have changed.

This collection of Elektor magazines I grew up with — obsolete.
A collection of GE Ham News that someone spent money on to have nicely bound — obsolete.

Byte magazines? Obsolete.

Creative Computing? Not quite yet obsolete.

And even if I can’t find it online, scanning and dumping* is better than storing the originals until my container is auctioned off one day.

Don’t get me wrong — I’m still keeping mountains of stuff. Just not… this stuff.

 

* Yes, Jason doesn’t like dumping. I’m not dumping anything that’s even slightly rare, so chill.





3
Dec
'14

Well, almost. In Ham Speak, a boat anchor is an old, large, probably obsolete piece of radio equipment. I have more than one.

However:

The Heathkit HW-32 only qualifies if you have a tiny boat. At about 30cm wide and 15cm high, it’s actually quite small for a 14 valve transceiver rated for 200W PEP output. OK, it only does this on a single band, 20m in this case (the HW-12 and HW-22 covers 80m and 40m respectively).

Frequency coverage is 14.2 to 14.35 MHz, for mobile SSB operation. There’s no provision for CW and no coverage of the CW portion of the band.

At 5 1/2 kilos, it’s also too light to be a boat anchor — but that’s because it doesn’t have a built-in power supply. You need to supply 800V DC, 250V DC, and -130V DC bias, as well as 12V for the filaments.

We’ve come a long long way in 50 years.

 





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