The Intel 8088 has a nasty bug.

It has to do with string operations. The 8088 has a number of instructions that work on blocks of memory. They include SCAS which scans memory, CMPS which compares memory, MOVS which moves copies memory, LODS which loads (reads) memory, and finally STOS which stores (writes) memory.

When paired with a REP prefix, these instructions keep going for a count of bytes/words equal to CX. That means in the worst case scenario you could have 64K iterations, which could take over a million cycles to execute.

That's quite a while, especially with a slow CPU. So these instructions are interruptible.

#retrocomputing #vintagecomputing

Analyse des titres de transport de Montpellier (TAM) - oui ça tient en un seul toot

La ville a rendu le transport gratuit uniquement pour les habitants, ce qui nécessite de garder des contrôleurs et une billettique 💀 mais la validation a été supprimée.

Les tickets sont simplement horodatés par l'automate au moment de la vente avec de l'encre et valides 1h30. Il n'y a ni encodage magnétique ni qrcode ni puce ni rien.

I'm giving away all my Sparc hardware:

2x SparcStation 10s
1x Lunchbox form-factor 32-bit SparcStation, maybe an LX? Basically a single processor SS10 in a lunchbox form factor with a microSparc CPU
1x Ultra 1e that doesn't boot with a graphics card
1x Ultra 5 with no cards or any other accessories

And a bunch of other random related stuff including some HDDs for the Ultra1e, several sBus graphics cards, an sBus ESP wide SCSI card, some random SCSI cabling and adapters, and an mBus HyperSparc CPU.

This is free to anyone who can either:
- collect it from the inner west of Melbourne
- or lives anywhere within ~15km of a line between the Melbourne and Geelong CBDs that is accessible by car (if you're not sure, ask)

I'm not going to split this up, so if you don't want all of this, please give away or recycle the rest.

I'll update this post when it's gone.

(Please boost for reach, I'd really like to give all of this away instead of recycling it)

#freetoagoodhome #sparc #sparc64 #sparcstation #sparclinux #giveaway #fleamarket #ultrasparc

Just for fun, I also confirmed that I can output 15kHz video and get around 832x288 pixels. I tried interlaced mode but it is flickering and uncomfortable.
Also this is pushing the timings a bit, you can see the scanlines getting noticeably wider accross the screen, not sure how to improve thatbut I can tweak the timings further.
Also, uboot doesn't have a 8x8px font, that would be helpful here. And I didn't manage to enable the 4x6px one.

Electronics pro tip: whatever sketchy thing you're doing, putting the plastic casing on your DB and DE connectors will make it look more profesionnal (and less likely that you break a solder joint)

Someone at the sticker factory decided to have fun with fonts

Now let's get a serious operating system running! The good news is this is not any more broken than last time I tried. The kernel is loaded from the network and started, but it doesn't have a driver for the network interface yet. So the remote rootfs can't be found.
Let's port a driver!

Ok I'm done with adjusting the timings for this display for now. The refresh rate is somewhere between 50 and 60Hz and this is as sharp as I can get it in this setup (I could bypass all the vga stuff and wire the lcd panel directly, but it doesn't use the right connector and I want to keep this usable as a vga display)

My Zoom F3 talks now.

As a blind field recordist, I've modded the F3's firmware so it speaks: every menu item as you scroll, which option is selected, popups like "SD Card Full!", confirmation dialogs, and even the date and time setup. No sighted help needed.

Would you want a step-by-step guide, with no technical knowledge needed, to put this on your own F3?

#Accessibility #Blind #ZoomF3 #FieldRecording

Ada lovelace day : j'ai dans mon disque dur depuis longtemps une petite collection d'affiches que nous avions faites avec Liz Walton, Philip Tchernavskij et Wendy Mackay il y a quelques années pour venir hacker une galerie de portraits d'informaticiens masculins qui peuplait les murs de la bibliothèque du labo. On les avait mises sous cadre et accrochées en loucedé. Je partage ici en fil… #adalovelaceday

Generating VGA using the Allwinner V3s LCD controller

https://pulkomandy.tk/_/_Electronique/_Generating%20VGA%20Using%20The%20Allwinner%20V3s

I'll have to try and see if I can set the display engine to emit an extra black column at the right of the display to work around that.
It also took me wny too long to realize that I can poke the lcd controller registers manually from the uboot hromht instead of rebuilding everything to test different timings

Today I tried to improve the vga timings. I use the LCD driver on the allwinner v3s and some resistors to imhlement a cheap vga output. I determined that my vga display has a 800x480 panel, but couldn't figure out the right timings. It always has a few extra or missing columns to the left and right.
I also noticed that during the blanking and porch, the rgb lines retain the last pixel value and are not reset to 0, which creates some glitches.

Things done today:
- my lichee pi baseboard yocto is up to date with current yocto versions. But I'm not so interested in doing linux things anymore
- configured it for 15kHz output, but it can't do composite sync and my cable to commodore 1084s is missing the vertical sync pin
- struggled to test my changes due to my laptop pretending to write to sd cards out not doing it, wasted a lot of time
- ordered the right din connector for the cable, and several other parts from my "to order" list

Am I missing something here? Or should I burn this computer and get another one?

I erased the entire card with dd from if=/dev/zero (and also tried to write other things to it), it shows as empty, but it still has a partition that I can mount. This persists after ejecting and reinserting the card.

Trying to run fdisk on it also doesn't see a partition table. But the kernel does, and finds a partition.

The SD controller is 1217:8621 O2 Micro, Inc. OZ711 SD/MMC Card Reader Controller (rev 01)

Beta testing time!

If you have a #windowsce device around, you can try the CAB file here and see what happens:

https://gitlab.com/GrafX2/grafX2/-/jobs/17041705178/artifacts/file/install/GrafX2.CAB

Do you get a nice painting program, or do you get a crash? :D

Anyway, there's apparently an SDK and a custom programming language (seems smallalk or java-ish with a custom C-like syntax and reference couning memory manager). Unfortunately all closed source. I may have a try at making an app someday to display the day's nearest geohash point direction and distance

I am sad that things did not go that way, and also that rost reviews for this watch complained about the black and white display, not understanding why it's a good idea:
- MIP (memory-in-pixel) displays don't need active refresh. Keeping it always on uses limited power
- transflective display, highly visible even in direct sunlight
- there is a solar cell under the display (even if most of the charge comes from the part of the solar cell that's around the display)

I have a Garmin smartwatch now (for health monitoring reasons). It has a monochrome 160x160 pixel display, and oespite having only a tiny battery and running a not of sensors, bluetooth, gps, etc, it lasts for a month or so, even more if you spend enough time in the sun to recharge it.

Specifications seem similar to Palm PDAs. So, if we wanted to, we could have computers that fit in your pocket and can run forever on solar power (you'd have shace for more solar panel surface and more battery)

Ok, we have a shortcut!
It's not so complicated in the end, but the documentation for cabwiz that I could find is very unclear. It helped to add some logs to the hython code and know what I expected to see in the generated "manifest" file.