Older blog entries for svo (starting at number 51)

T80 Core To Be The Most Precise 8080 To Date

8080 Emulation Quality



8080 has many dark corners. Unlike its more popular successor Z80, 8080 had never been studied enough and most emulator code, and FPGA cores, relied on data from various books and often even word of mouth. Thusly, it's known that DAA instruction doesn't yield correct result after subtration but it's not known why and AC flag has mysterious ways too..
Just recently a few enthusiastic people from a Russian Vector-06c fans forum found a piece of software for Vector-06c which could not be started in any of the existing emulators, couldn't be started in my FPGA replica yet had no problem running in the real Vector-06c at all. After some investigation it turned out that 8080 ALU had AC flag inverted after SUB operation. This involves SUB, SBB, SBI, DCR, CMP, CPI instructions. The pesky ware used the contents of 8080 flags register as a branch address. Ultimately it led to this discovery of auxilliary carry anomaly.

While fixing this issue in the T80 core, which I use in my Vector-06C replica, I discovered a lot of other discrepancies with the original CPU. Thanks to the ultimately inquisitive CPU test written by Ian Bartholomew, 8080 Exerciser, I was able to verify my version of T80 against the baseline set by the real CPU in a real computer.

Probably not an earth-shattering news, but this is a milestone in emulation of 8080 CPU nevertheless. As of now, there are no known tests that could tell my version of T80 in 8080 mode from the real thing. Update your emulators or you're going to lose the edge :) Only my version has these changes at the moment, they had not been merged with the "official" opencores.org version.

One thing worth noting: real CPU tests were done on a KR580VM80A, which is known to be a gate-level clone of 8080, but still not exactly the real thing. If you have a real 8080 CPU computer which can run CP/M 2.2 or similar, please try Ian's test on your computer and send the results to him or to me.

Syndicated 2009-09-23 21:21:02 from svo's interactive persuasion vehicle

Motöri the Plotter Video



Chaos Constructions 2k9 is over. It was the most awesome party ever. I had several exhibits, the primary one was of course the Motöri and the crowd totally loved it.

Since it's not a very reliable contraption, I prepared a video to show in case I won't be able to run the plotter live. Everything went smoothly and it wasn't necessary, but the video is pretty nice and it shows the plotter from every possible angle and lets you hear its lovely sounds. Enjoy!

Syndicated 2009-09-01 14:37:09 from svo's interactive persuasion vehicle

The Release (2005)

Arvaa mikä päivää?



PERJANTAI!
This happened in 2005.

Syndicated 2009-08-12 14:13:55 from svo's interactive persuasion vehicle

Обновление «Базиса@home»

An update of the offline version of Bazis, the Vector-06C database: Bazis@home: 754 records.
Direct link for the online-challenged: some megabytes

Обновление оффлайновой версии картотеки программ для Вектора «Базис@home»: 754 записи.
Ссылка на архив: много мегабайт

Syndicated 2009-08-05 22:57:03 from svo's interactive persuasion vehicle

Принцип Бернулли — почему шарик не падает

Почему шарик не соскальзывает в сторону, когда он болтается в струе воздуха. Рассказ с иллюстрациями.

Why the ball doesn't slip away when it's levitating in an air jet. A short illustrated demo. No English captions, sorry, unless I figure how to do them faster than doing the rest of other video tasks combined.

Syndicated 2009-08-01 14:21:43 from svo's interactive persuasion vehicle

okno okno

24815162342 39382479.26256002.1248022598.bcc655af6d541849e4f769e6959d5d2e

Syndicated 2009-07-19 16:58:59 from svo's interactive persuasion vehicle

Motöri The Plotter gets a Laser

Моторий теперь вооружен 300мВт лазером.

Motöri now wields a 300mW laser.

Woodburning the Pionner plaque

English link: Motöri
Русский линк: Моторий

Syndicated 2009-07-16 16:47:46 from svo's interactive persuasion vehicle

Perjantai

Arvaa mikä päivää?
Perjantai!!!

The music for this was composed on a real C64. Duh.

Syndicated 2009-07-10 12:58:02 from svo's interactive persuasion vehicle

Как двигать головками дисковода с помощью энкодера

Я рассказываю, как можно двигать головками дисковода с помощью одного энкодера, не прибегая к помощи микроконтроллера и компьютера.

I tell how one can use a rotary encoder to directly control floppy heads without using a microcontroller or a computer. The video is closed-captioned for English viewers.

Syndicated 2009-07-04 17:27:30 from svo's interactive persuasion vehicle

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