Oldskooler Ramblings

In the USA, Kingston supports cross-shipment.  So I already have my replacement RAM.  Two days later.

With a lifetime warranty and such speedy RMA/warranty service, I think they’ve earned my money for life.

In 25 years of personal computing, I have never once had RAM go bad on me. So when my Athlon box started to reboot randomly, I was initially at a loss to troubleshoot it. It was only after a few sobering minutes in memtest86 and switching sticks from slot to slot that I learned both of my KVR400X64C25/512 sticks were bad. No idea how they got that way; one was REALLY bad (half of it is trashed), and the other I probably could live with (only a few single-bit errors) but I filled out an RMA for both of them anyway. I don’t need my main desktop randomly flipping bits on me.

I learned two things from this experience:

• Lifetime warranties are good.
• With my Athlon out of commission for a week, it’s so… quiet in here.

Maybe I’ll finally get some console game-playing in.

This weekend was spent obsessing over the fastest text editor I could find for a 4.77MHz 8088 that had a functional undo. The results were a bit too lengthy for a blog post, so you can view the article I posted regarding the subject.

Nerd Alert:  If you’ll never type on an XT for more than 10 minutes at a time for the rest of your life, don’t bother reading the article.  There are much better things to do with your time :-)

That was the IM I got from a “friend” who shall remain “nameless” who was “unhappy” with the state of my “blog”. Fine, so I’ll post something, but for the record I have had excuses for not posting the last four weeks:

• Not losing weight, so that alone is depressing
• Went to GDC and was very sick the entire damn time (although I did have some good experiences; more on that later)
• Still sick 2.5 weeks later (yes, I’m seeing a doctor)
• Weathered a layoff storm at work, sometimes violent, sometimes petty
• Child problems at school

etc. etc. My life is actually quite privileged, and it sounds utterly ridiculous to complain, but I am human, which means I’m damaged, and this stuff affects me. I know it’s irrational. I’m sorry.

So, until I can lose some weight or report on some other stuff that is actually interesting to someone, I’m going to Post Something Dammit. Today’s PSD is on the topic of: 8088 CPU bugs. It’s time for some st00pid k0mp00ter history! Yes, the 8088 had bugs in the first iterations. Forget the Pentium FDIV bug; they’ve all had issues from day one :-) Two of the bugs were caught by Intel in 1982-ish, but not until 200,000 IBM PCs were sold. The third was fixed in the 80186.

The first two bugs involved interrupts and the stack. The first bug was that a MOV to SS (the stack segment) did not disable interrupts for the next instruction, meaning that you could get an interrupt in the middle. This is bad, because the interrupt will try to set up it’s own stack (something you were trying to do with the MOV SS!) and the stack is unlikely to recover, taking the machine with it. The workaround was this:


CLI
MOV SS,DX
MOV SP,AX
STI


ie. disable interrupts before you do the switch, then re-enable them when done. Which sucks, but is a good practice that I would imagine most people were doing anyway because they didn’t know that MOV SS,reg was a special case that was supposed to disable interrupts. Hell, I didn’t even know that until I started researching the bug.

But not all was good in Intel land: If you didn’t know the state of the interrupt going in, then you were supposed to preserve it, like this:


PUSHF
POP BX
CLI
MOV SP,word ptr [my_stack]
MOV SS,word ptr [my_stack+2]
PUSH BX
POPF


…except there was a second bug in the original 8088 in the POPF opcode which meant that, even if the state was still CLI after the POPF, interrupts would still be enabled for a single cycle! Try tracking THAT bug down in your program! So the workaround, which is just st00pid, is to fake POPF using IRET. (BTW, the odds of this particular bug cropping up is somewhere in the neighborhood of 1 in 5 million, and only when you switch stacks, so it is such a longshot that I never bother in my own code.)

But wait, there’s more! There’s a third bug where, if you try to use a segment override on MOVS or LODS (ie. so you can attempt to use something other than DS as the source) and an interrupt fires off during, say, a REP MOVSW, it stores the wrong return address. This was fixed in the 80186… I think. Not sure. I’m not sure that behavior is even officially documented so I’ve never had the urge to try it.

Now that the MindCandy Volume 2 is finished, it’s time to archive the project and get all 550 gigabytes of it off of the video rig so that I can completely retrofit the rig with service pack 2, new drivers, the works. Compressed, it will fit onto about $20 of DVDs, so I decided to kill two birds with one stone and buy some 16x DVD-Rs and some 16x DVD+Rs to see which is faster.

The results are disappointing. They both suck, never coming anywhere near the rated burn speed until the very end of the disc (which is the last place you need speed).

Back when the DVD format wars were new, one of the major differences noted between the formats was that DVD+Rs burn at CLV (Constant Linear Velocity, where the disc slows down toward the outer edge so that data is burnt at the same speed “under the laser”), while DVD-Rs burn at CAV (Constant Angular Velocity, which means the disc spins at the same rate throughout the burn). CLV burns slower, but supposedly results in a higher quality burn. So you would think that DVD-R would spank DVD+R in terms of speed, right?

Wrong again. Burning 100 meg shy of a full disc, here are the numbers on my LITE-ON DVDRW SHW-160P6S PS0B:

• 16x DVD-R (Disc ID: RITEKF1): Average Write Rate: 15,208 KB/s (11.0x) - Maximum Write Rate: 21,779 KB/s (15.7x). Burn completed in 6m29s.
• 16x DVD+R (Disc ID: RICOHJPN-R03-04): Average Write Rate: 15,208 KB/s (11.0x) - Maximum Write Rate: 21,792 KB/s (15.7x). Burn completed in 6m20s.

They’re the same! Worse, the best you can do with a 16x drive feeding it 16x media is really 11x. At that rate, I’ll just keep buying 8x media; they cost less, but only take 80 seconds longer to burn.

So, what’s the point of 16x again?

My wonderful, trusty, always perfect six-year-old Sony G400 19″ Trinitron CRT monitor expired this evening. (I’m typing this on the company laptop.) Which leads to a very interesting problem: How to buy a new CRT?

The question isn’t really a serious one, since you can still order CRTs via the web. But the number of models produced, along with their quality level, is diminishing almost down to nil because of LCDs. I haven’t bought a monitor since the G400, and in those six years the landscape has completely turned 180 degrees: LCDs are now the preferred monitor for new computer purchases. There are new models out all the time, their prices are dropping while sizes are increasing, and they have greatly reduced energy consumption and radiation levels.

My problem is that, for my needs, they all suck.

There is no LCD that can do what I need out of a display device. Before you scream “gaming!”, I am already aware that response times have gone down to 16ms and below, making a true 60Hz refresh rate possible. But I have two very basic needs, one old and one new, that LCDs cannot accomplish today — and, in the case of one need, will never be able to accomplish:

1. Color depth: I need full 24-bit color out of my display device because of the video work I do (yes, I also have an external broadcast monitor, but I like to work in resolutions greater than 720×576, thanks), and LCDs today are capable of about 18-bit (cheap) to 20-bit (expensive) color output. If you don’t believe me, create some (non-dithered!) gradients in Photoshop of red, green, blue, and luma (black to white) of levels 0-16 and 236-255. Make those gradients go all the way across the screen. You should be able to pick out each level, right? Well, try. You’ll see that some of them are getting posturized.
2. Multiple resolutions: LCDs have a fixed resolution. If you want to work in a different res than what the LCD provides — like, oh, I don’t know, lowres oldskool gaming — you have to settle for some stretching of individual pixels. No matter how good the algorithm, it looks like ass.

My CRT hunt begins. If you know of any decent, professional 19″ or 21″ trinitron CRTs for sale under $400, lead me to them :-)

I am pretty proud of myself when it comes to the TV situation in our house: I own a ReplayTV instead of a TiVo, so for over two years I've been able to stream shows to any PC in the house (wirelessly), can dump shows to DVD, and generally hold more programming than I have time to watch. (This functionality was only recently duplicated by an unsanctioned TiVo hack, so TiVo owners, I fart in your general direction.) I'm even proud of myself for finding a free MPEG-2 player (VLC), with not only proper 60Hz progressive display of interlaced material, but also a mod to automatically skip commercials using the ReplayTV's built-in commercial-skip metadata. So, when it comes to watching DVR shows, I'd like to think I'm pretty bad-ass.

Last night I was settling down in bed to watch shows before I hit the sack, and I pulled up DVArchive and checked the list of shows I had downloaded and waiting for me:

• Daria
• Doctor Who
• Miami Vice
• Saturday Night Live
• The Outer Limits

All I could think was, "My god! I am such a flaming nerd!"

There is a great quote from David Cain that explains the birth of most of the underground electronic art scenes, like the demoscene, tracker scene, or ANSI/ASCII art scene: "It is the point where the desires of the creator are greater than the technology which is available." An expanded citing of this quote also reveals how such scenes can self-destruct, and helps illustrate why I dropped out of the demoscene in 1997. It goes:

There comes a moment where the technology gets closer and closer to the imagination and creativity of the writer, and in the end, if you're not careful, it overtakes. And suddenly, serendipity — which before was from your own sweat and blood — comes by saying "If I press one of these 397 buttons, maybe I'll get something out of it." Now, at that moment, the machinery is driving the creativity, and the creativity is (no longer) driving the machinery. — David Cain, BBC Radiophonic composer from 1967-1973

Of course, the challenge is for the end of one age to become the beginning of another.

While this isn’t technically true, I can definitely see how this myth was formed. My father ran on a 486/66 with a modem from 1995-2001. In 2001 he got cable modem broadband, but his 486/66 was so slow that it couldn’t process complex web pages much quicker than it already was, so he saw no actual speed benefit. So he went back to the modem, at which point I almost lost it (”How can you want to go slower?!”)

Later he upgraded to a Pentium 3 @ 450MHz, and could finally perceive the modem as a bottleneck.

Ironically, two years later, I did the same type of thing (downgrade powerful hardware): Through a telephone conversation mix-up, I agreed to reserve and purchase a Yamaha snowblower — and when I got there, I had reserved the wrong one. What I thought was going to be a $600 18- or 24-inch blower was actually a $1300 36-inch semi-industrial model. I was coerced into buying it because renigging on the reservation meant I would be charged $50 because these things were in demand in the middle of winter. So I bought it to avoid the fee, took it home, opened the box, took one look at it and knew I could never use it for my tiny driveway without being embarrased (it wouldn’t even fit in my garage with both cars), and proceeded to box it up and return it. On that day, a snowstorm began. As I’m returning this monster snowblower, I get a goofy look from the kid helping me; when I inquire, he says, “I’ve just never seen anyone return a snowblower in the middle of a snow storm!”.

Oh yes it can. Here’s a story for you: In my teens, I had a friend who got the IBM 5155 (the Portable Computer — you know, the heavy luggable one with the monochrome CRT monitor inside it) from a Computerland. He was screwing around with POKE in BASIC and POKE’d a value somewhere into CGA-land, saw some pretty squiggles for about 3 seconds, then poof and we smell the familiar smell of ozone. We went back to Computerland, but they told him that there was no way that software could have damaged hardware and they weren’t going to repair it (thinking that he had dropped it or something). So my friend, with salesman watching with one eye from across the room, walks over to another one on display, takes the diskette out, boots into BASIC, writes a 1-line program, and poof, ozone, and no more monitor. Salesman didn’t quite know what had happened, so my friend walked over to another one on display and does it again, but steps aside so that the salesman can see it this time.

Let me tell you, I’ve never seen an overweight, balding, 50+yr old move so fast. He sprang like a gazelle toward us and for a second I thought I was going to get the crap beaten out of me. Thankfully, all he did was yell, about how we were going to have to pay for that, etc. This got the attention of the manager, who came out and said they’d honor the warranty and fix his machine if the kid would stop blowing up all the IBM 5155 monitors in the store.