Predecessor of the SIMM?
This comes from a piece of medical equipment made by the other S&W, Simonsen & Weel, Denmark, circa 1979.
Each module has 8 x AM2808PC 1024-bit dynamic shift registers, driven by a DS0025CN two-phase clock driver. That’s one kilobyte of storage per module, and you have to keep on clocking the data around the ring otherwise the capacitors making up the memory discharge and forget.
It’s a lot simpler than a mercury delay line memory, but functionally it’s not that much different.
Now go away.
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.
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.
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 :-)
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.
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.