What is that?
It's a duck pond.
Why aren't there any ducks?
I don't know. There's never any ducks.
Then how do you know it's a duck pond?

Wednesday, July 31

Geek

Daily News Stuff 30 July 2019

Women Minorities Hardest Hit Edition

Tech News



Disclaimer: In the future, every package manager will be a teapot for fifteen minutes.

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Monday, July 29

Geek

Daily News Stuff 29 July 2019

One Shiny Aluminum Penny Edition

Tech News

  • AMD might have some more Ryzen 3000 parts on the way.  (Tom's Hardware)

    It could be an error, but the document does specifically list a 65W Ryzen 3900 non-X part.  A 65W 12 core CPU is pretty impressive stuff.

    Now they just need to get them into servers.

  • Now you can Switch to Android.  (WCCFTech)

    On your Switch.  With Android.  Which now runs...  Never mind.

  • Oh look more malicious code delivered right to your door by NPM.  

    These are far from the worst examples of useless crap masked as packages in NPM; one is nearly a hundred lines of code.

  • I went to London and I got was this lousy pencil.  (The Guardian)

    Only in 70 AD, and in Latin.

  • Notqmail is a successor to Qmail.  (Github)

    Actually, it is Qmail.  Mostly.  There are some recent updates, bust most of the code is old enough to vote.

  • HyperCard died because it was too beautiful to live.Money quote:
    And if you think that XCode, Python, Processing, or the shit soup of HTML/Javascript/CSS are any kind of substitute for HyperCard, then read this post again.  And if you continue to think so, then you might be an autistic typical software "engineer,” and please don’t waste your time commenting here.  Sink back into the cube farm hellpit from whence you came.
    Yeah, that's the stuff.

  • TSMC discuss their N7 (7nm), N7P, N7+, N6, N5, N5P, and N3 fabrication processes.  (Wikichip)

    N7 is in full production now; N7+ and N7P are ramping up.  N3 won't reach production until 2022, so between now and then there are only five upgrades in the pipeline.

    After AMD spent five years stuck at 28nm, this borders on the ridiculous.

  • AliBaba has announced its own 16-core 64-bit CPU.  (The Register)

    It's based on the open-source Risc V core so it's not a remarkable feat of engineering, but interesting nonetheless that this came from a shopping mall rather than a major semiconductor company.

    It's been done before though.  Back in 1980, Scottish hi-fi company Linn developed it's own CPU from the ground up to improve its process automation.  (Wikipedia)  Money quote:
    The last known copy of a Rekursiv computer ended up at the bottom of the Forth and Clyde canal in Glasgow.
    And stay out!

  • YouTubers are unionising.  (One Angry Gamer)

    I didn't know they'd been ionised in the first place.  Maybe check the power supply.


Retrocomputing Journal

There are no good small project cases.  They're all garbage.

About the smallest size you can get a nice looking case is mini-ITX.  Something like this:

http://ai.mee.nu/images/A750Case.jpg?size=600x&q=95

That one is A$70 from Amazon Australia, nearly as much as the entire rest of my BOM including a four-layer mini-ITX sized board and PCB assembly in qty 20.  Some of them run about US$25 each on AliExpress, but the one I particularly like with no visible screws is naturally among the more expensive.

It's so pretty I'm not even sure I want to drill a dozen holes in that front panel for the LEDs.

I also started on a BOM for the A1250, the version with the Renesas RZ/A1 and 3MB internal RAM instead of 1MB.  It uses many of the same components, but adds about $12 for more powerful CPU, supports DVI, adding another $12, and a lot more flash storage and a RAM expansion option, totalling another $12 or so.

Board and assembly costs are identical - because it has only three more components; it just uses more expensive components - about $20 in qty 20, falling to $8 in qty 200.

So for a small pre-production run, the A750 is looking at around A$75 for a complete board, and the A1250 about $110.*  In a run of 200, about $60 and $85 respectively.  Add $70 for the nice case (or $40 for a fairly nice case).... 

And $225 for the keyboard.

Ouch.


* The A1750 would run about $185, so I'm not even thinking about that at the moment.**

** On the other hand, I've found that I can get the RZ/A1M from Avnet for about A$6 more than the RZ/A1LU, and it's a much better chip.  Instead of 3 graphics planes, it can produce a total of eight.  Normally those would be across two screens, but that magical FPGA retimer can fix all that.  Might need to bump it up to have more pins if it's acting as a video crossbar as well as a scaler though.



Video of the Day

Meanwhile, here's a project built using a Chinese microcontroller that costs three cents in small quantities.




Disclaimer:  Ack.  Pfft.

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Sunday, July 28

Geek

Daily News Stuff 28 July 2019

One Man's Treasure Is Another Man's Treasure Edition

Tech News



Retrocomputing Journal

A couple of weeks ago my video of the day was an exploration of an enormous warehouse stacked twenty feet high in classic 8 bit and 16 bit computer hardware, ranging from old broken stuff that had been exposed to the weather for years and was basically unrepairable, to complete original systems still factory-sealed.


A few different retrocomputing hobbyists took the time to sort through the place (the owner is getting old and apparently not in the best of health) and more importantly, to take video of everything.  And an eagle-eyed viewer of one of those videos said:

WAIT STOP GO BACK THAT'S A @&#*#@&$#@ MINDSET!!!!!!

And indeed it was.



Here's Mindset serial no. 854, complete and in perfect working order (the only thing that needed replacing was the fan), with original keyboard, mouse, joystick, expansion cartridges, software, and all documentation including programming guide and service manual.  There's even a dump of the custom BIOSes available.  (Several of them since it has two ROMs for the CPU and two embedded microcontrollers.)

Mindset 854 is a fully-expanded unit with 256k RAM and dual floppy drives.  And one - count them - one game.

Mindset was not a financial success, but the engineering here was better than anything that came to market for the next...  Ever.  Look at those expansion slots.  You pop the slot cover off, push the expansion cartridge in, and off you go.  None of the bullshit you have to go through with "modern" computers.  Just plug it in and go.

Anyway, they've gone back and scoured the warehouse and discovered more Mindset stuff, presumably in various states of completeness and repair.

And there is now one video about the Mindset on YouTube.  It's search result #5 for me.


Meanwhile, I've started on a BOM for the A750 as a sanity check.  Not including the case, PCB creation and assembly, or power circuitry (which might be very simple - the H750 only uses 500mW at full load), it comes to A$44.56 in qty 1 so far.  (Plus up to $25 in optional extras.*)

That includes:
  • STM32H750 microcontroller

    400MHz Arm Cortex M7 with 1060k RAM.  Might actually be 480MHz by the time I get anything working, because they're updating the stock with a new version.

  • iCE40HX1K FPGA

    Video upscaling and retiming; I'm proceeding on the basis that it will be needed.

  • Intel 5M80Z CPLD

    System controller, console video, and 74LS avoidance mechanism.

  • USB2514 hub

    This will convert one USB port from the microcontroller to four downstream ports.  Another advantage is that it has built-in ESD protection so you're less likely to blow up the entire system just plugging in a keyboard.

  •  2 x Winbond 8M NOR flash

    One in QSPI mode for running code (read-only in normal operation), the other in SPI mode for read/write storage.

  • 2 x VGA output

    One full-colour graphics, the other just for a two-colour text console for programming and debugging.

  • 2 x TinkerPort

    DA-26 port combining 8-bit parallel, 4-wire serial, 5V and 3.3V power, fast and slow clock sources, and GPIO on whatever pins are left.  One external for hacking, one internal for expansion.

  • 1 x USB type B

    Upstream connection to a PC or power supply.  Might be a micro B instead.  Carries both data (for programming / debugging / file transfers) and power (for power).

  • 4 x USB type A

    Two of the common two-high stacks.  USB 1.0 only unless I add a an external PHY.  Hmm.  How much is an external USB 2.0 PHY anyway?  Oh, A$1.90 qty 1.  I'll add that to the list for consideration.  Though with only 1MB RAM and 16MB storage you can transfer the entire system contents in or out over USB 1.0 in less than 15 seconds.

  • 10 x indicator LEDs 

    Mostly because I can get 3mm LEDs in 10 different colours at about 2¢ each.  Box of 500 for $10.74.

  • 21 0.5% resistors for VGA DACs

    15-bit colour on the main port, 6-bit on the console so you can have something resembling an amber or green screen.

    Plus a bunch more 1% resistors for general pull up/pull down/current limiting/whatever.

* Oh, need an SD/MMC slot or two. Those are about A$2 each. And at least one 1/8" inch audio jack. That's about $1, and I even get to pick a colour. So that's a another five bucks.  All drop rapidly to about half that price even in small volumes.

The other possible addition is general-purpose serial ports.  Not sure how much that is needed with upstream and downstream USB and the two TinkerPorts.  But RS-232 drivers are dirt cheap (at least if you do a minimal null-modem connection), and RS-485 isn't too expensive.

Replacing the main VGA port with DVI-I is the single most expensive option; that's a $12.38 difference for the driver chip and the DVI-I connector itself, which is about three times the price of a DA-15.

Actually, the most expensive option is the custom keyboard.  Those are US$160 each with Cherry MX Brown keyswitches, so probably three times the price of the computer itself.


Disclaimer: 3mm white, warm white, pink, red, orange, yellow, yellow-green, green, blue, and purple LEDs are about 2¢ a piece, with flat or rounded cap.  IR transmitters and receivers around 5¢, and the H750 supports IRDA, so I'll look into that.  Can also get amber (if that's different to orange), cyan, and turquoise, and various two-colour and colour-cycling variants.  But not proper RGB, not in 3mm.

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Geek

Daily News Stuff 27 July 2019

Ducks Guts Edition

Tech News


Video of the Day



Anime gets everywhere.



Retrocomputing Journal

I've renamed the design from the A800 to the A750 because, duh, the processor is the H750.  If I follow up with the second design it will be the A1250 because the processor is the A1.

I've done a keyboard layout which can actually be made if this goes ahead.  Not cheap to order one, because it's all Cherry MX keyswitches, but hey.

https://ai.mee.nu/images/A750Keyboard.png?size=720x&q=95

I now know how to do AM, FM, and PWM via LFO on a software wavetable synthesizer; the FPGA I was thinking of using has dropped in price by 20%; and there's also a CPLD I can use for under A$3.

Advantage of the CPLD is that it's nonvolatile and starts up in half a millisecond.  Also, cheap.  The problem I had with the FPGA is that it's terribly inviting to use it for system control as well as the video controller, but then if you mess up while reconfiguring the video controller the whole system stops working.

So an $11 MCU for all the hard stuff, a $3 CPLD so that I won't need to suddenly add a random AND gate or latch somewhere, and a $7 FPGA to do video retiming and upscaling from the built-in LCD controller to proper 1080p - only if I can't get that to work in software, which I'll find out after the developer kit arrives.

As a nice touch they're all QFP-100 packages, which is not in any way necessary but is nice and clean.  CPU and custom chips all lined up neatly.  Hmm.  Need a QFP-100 DSP with 16-bit DACs...

That system control CPLD also means I can add a second VGA port running off a spare SPI output, in monochrome or possibly in character-cell colour.  So you can run one screen off that while you tinker with the settings for the LCD controller and FPGA on the other.  The added cost is just six resistors and the D-15 socket itself.

Update: Wait, how many SPI ports does the H750 have anyway?  I've assigned one to the "hard drive", one to console video, one to the TinkerPort, and one for internal expansion (which might be another TinkerPort).  Which is four gone before even thinking of anything else...  Six.  It has six.  Good.



Disclaimer: Flat out like a chicken dazzler.

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Saturday, July 27

Geek

Daily News Stuff 26 July 2019

One What Edition

Tech News



Video of the Day



This looks like fun.  The A800 won't have enough memory to really do sample-based sound and won't have an analog synth because they're pretty much gone - though there are plenty of Yamaha OPL2 and OPL3 chips floating around on sites like AliExpress for a dollar a piece.

But the H750 has plenty of processing power to fuss about with audio waveforms, even including DSP extensions.  And this looks like it's mostly straightforward programming so long as you have the CPU performance.

Basically, as far as I can see, I can start with a table of a sine wave, say 128 16-bit values.  The CPU scans through the table at, say, 96kHz, working out the next value to be output based on the selected frequency and a bit of interpolation.  Easy.

Then I add an ADSR envelope, which is amplitude modulation of that waveform.  Also easy.  I can make that a second 128-value lookup table, with a much lower frequency, automatically generated from the specified parameters, and just multiply with the audio sample.  That makes it dead easy to implement inverted and multipoint envelopes like DAHDSR (with delay and hold parameters).  Once the envelope waveform is generated it's just a bunch of MAC operations.

The next trick that is also easy is to shift a voice between wave tables in a pattern controlled by an LFO - low frequency oscillator - which can be done as yet another wavetable.  So at T=1 the voice will be a sine wave, at T=10 50% sine and 50% triangle, and at T=15 100% triangle.

Another way to envision that is to have two primary wavetable oscillators per voice, each with independent amplitude modulation.  Same result, but possibly easier to understand.

The next step beyond that is frequency modulation, where an LFO would adjust not the value from the wavetable but the index used to find the value in the wavetable.  With sufficient CPU power, though, that is also easy.

I need to find some more videos to see all the tricks these synths do, but so far I think it's all relatively straightforward.  DSP stuff can certainly get hairy, but this doesn't seem to be.

Update: Found what looks like a good series of articles on this.  (EarLevel Engineering)  The author points out that you need multiple wavetables per waveform to avoid aliasing as you increase the frequency.  That means more ROM space, but ROM will be plentiful.


Disclaimer: Bleep bloop.

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Friday, July 26

Geek

Daily News Stuff 25 July 2019

That'll Slow The Fish Down Edition

Tech News



Disclaimer: It's okay to reinvent the wheel if you want to emulate a 30-year-old wheel rather than have one that actually, I don't know, works, or something.

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Wednesday, July 24

Geek

Daily News Stuff 24 July 2019

It's Completely Fine Edition

Tech News

  • Way to go Steve, almost making me feel sorry for Nvidia.



    The RTX 2080 Super is about 6% faster than the RTX 2080.  And that's basically it.  The 2070 Super is much better value, and so is the 5700 XT.

  • AG Barr, who I was really warming up to, has joined the ban arithmetic brigade.  (Tech Crunch)

    He wants to outlaw unbreakable encryption.

    Unbreakable encryption is just arithmetic.

  • Walmart spent $17 billion to acquire Flipkart last year.  It was widely considered an unwise purchase.

    Just one of Flipkart's subsidiaries that was included in the transaction - mobile payments firm Phone Pe - is now estimated to be worth $10-$15 billion.  (ZDNet)

  • BipBop has acquired DupTape, a British DweebCore startup.  (Tech Crunch)

    Basically.

  • Anonymised data is not anonymous.  (Tech Crunch)

    Even if a database is only searchable in general terms and returns statistical results, with enough queries you can triangulate any individual.

    This is not new.  We covered this in my Databases and Networks class at university, which was, oh, several years ago now.

  • An 8-core AMD APU with Navi graphics has surfaced on a benchmark site.  (Tom's Hardware)

    It's evidently a power-constrained part, with a base clock of just 1.6GHz and a boost clock of a more respectable 3.2GHz.

    Graphics were identified as Navi 10 Lite running at up to 1.8 GHz, which is encouraging, because the recently released Radeon 5700 and 5700 XT are Navi 10, and clock in the same range.

    If this is the Xbox Next chip, it promises to be twice as fast as the Xbox One X on graphics, and up to four times as fast on CPU.

  • Apple is looking to buy Intel's mobile modem unit because it's cheaper than dealing with Qualcomm.  (Tom's Hardware)

  • The developer board I wanted for my A800 project is back in stock, so I'll be getting that and polishing up my C skills.  Or maybe Rust.  But probably C.

    This has the STM32H743, the $19 big brother of the $11 H750 chip I want to use.

    It's the same core and peripherals, but with 2MB of flash instead of just 128KB.  For my own board I'm planning to add two external 8MB flash chips - one for code, one for data - which will cost a total of $2.76.  They just use a 4 or 6 wire interface so it's easy enough and gives a lot more flexibility.  For the dev board the 2MB is plenty and very convenient.


Video of the Day

Ever wondered what's inside a 40-channel mixing console?

Someone nodded!  Someone at the back nodded!

Here you go.




Disclaimer: Objects in the mirror are BEHIND YOU!

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Tuesday, July 23

Geek

Daily News Stuff 23 July 2019

Tuesday Teardown Edition

Tech News

  • Sure, Twitter bans conservatives every chance it gets and never admits to it but the White House website has a condent moderation policy so there.  (TechDirt)

    I see the bad Mike Masnick has the keyboard today, because this article is profoundly stupid.  Either that or deliberately disingenuous, but I'll assume he's an honest idiot.

  • Hackers are exploiting WordPress plugins to hack other computers.  (Bleeping Computer)

    Next step, they'll distributed hacking tools with secret backdoors via hacked WordPress sites so that when other hackers download them they can subvert their payloads to serve their own purposes.

  • Google not only removed Winter Wolves Games' games from the app store, they banned their developer account, because why?  Because Google is run by crazy people and cannot be trusted.  (Says Pixy, typing this in Chrome.  Sigh.)



  • Wired ran a puff piece on the creators of the new Twitter desktop app design which has 95% negative ratings.




  • Someone get this guy a 9845.  I love how excited he is about the HP 85 when in the previous video he complaining about how slow the spectrum analyser in his digital oscilloscope was when displaying a signal that was three times faster than this computer.



    This one is made of custom ASICs and looks to be pretty robust.  And the manual is full of sample BASIC code.

  • On second thought, give him a broken 9845.  It looks like he fixes broken computers  but breaks working ones.



  • 25 8" x 6" 6-layer boards printed, silk-screened, and assembled, with 120 SMT components and 20 through-hole parts (I have no idea if that is accurate, but it's a number) for $1000.  250 boards for $2700.  Adding more SMT parts doesn't increase the price much so long as don't use too many different parts.

    That would be a limitation of the pick-and-place machine.  They basically load it up with your components and let it run.  More boards doesn't increase the setup cost, and placing five of the same component from a reel just takes a few extra seconds for the machine.  

    But if you have too many different components that does increase the setup cost, plus they might have to put you on the big machine or do two passes.  Not sure exactly.  The assembly cost I'm looking at doubles when you go from 90 distinct components to 91, so I'm guessing two passes.  It's slightly cheaper to assemble something with 500 total parts of 90 distinct types than 100 total parts of 91 distinct types.

    I'm hoping I won't have even 100 parts, but those little SMT pull-down resistors and decoupling capacitors breed and multiple given any chance at all.

    Only problem is finding the money for even 25 sets of components, if I want to do the fancy build.  But it's an indicator if this ever gets anywhere.

    If I go for my simplest design - more of a Commodore 256 than an Amiga (though far below the scope that C256 Foenix project), 50 boards would cost around $680 to build and ship to Australia, plus components.  That's basically a $5 microcontroller plus a $2 NOR flash chip and some I/O connectors.  That I could potentially afford.

    Update: Actually, the simple version would be rather cheaper than that - it should be fine on a 4" x 4" double-sided board, which is a lot cheaper than an 8" x 6" six-layer board.  I got one quote for $370 for 50 boards, assembled.

Video of the Day



Sydney's new Metro line at sunset.  A lot of it is underground, but the bits that aren't can be quite nice.


Disclaimer: That's a big if.

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Monday, July 22

Geek

Daily News Stuff 22 July 2019

1,702,001,293 And Counting Edition

Tech News

  • More new websites are created every hour than existed in 1994.  (Internet Live Stats)

    Stop that.  Stop that right now.

    Half of all the websites in the world were created in 2016.

  • Dietary supplements are the new micro SD card.  (Ars Technica)

    Look for the "ships from and sold by" tagline, and even then double-check what you actually receive.

  • No.  No they can't.  Stop asking.  (Ars Technica)

    Even in 1994 they couldn't do that, not with a complete printed list of every website in the world.

  • The hackers hacked.  (ZDNet)

    A contractor for the Russian FSB got hacked and 7.5TB of hacking tools and related data exfiltrated and uploaded to PornHub.  I may have added that last part.

  • George sold his face for five lousy bucks and all he got was...  Wait, that doesn't work.  (ZDNet)

    "Truthfully, I didn't read the full waiver thing."

    Don't be George.

  • The C256 Foenix is an interesting project.

    It takes a 14MHz 65C816 - the same chip used (at a rather lower clock speed) in the Apple IIGS, adds three Altera MAX10 FPGAs for video, sound, and system control, and 6MB of static RAM.

    It is not, despite the choice of CPU, compatible with the C64 or C128.  It's not directly compatible with anything.

    The motherboard - the product of a single engineer - is a work of art that I'd like to frame and hang on my wall.  But it costs $299, so that probably won't happen.

    I can understand why it costs that much.  Not only is doing this a lot of work, there's quite the bill of materials there.  Apart from the CPU and the three FPGAs (each about A$11) there's three 2MB SRAM chips which could run to $15 a piece.

    You can see the DVI encoder chip too, though I can't tell the part number.

    Then there's a whole bunch of connectors - DVI-I (avoiding the HDMI tax), serial, parallel, PS/2 keyboard and mouse, MIDI in and out, a floppy connector, an MMC card slot, four joystick ports, and stereo RCA jacks for audio in and out.  Every one of those adds cost.

    The weak part is the 65C816 CPU, which is actually reasonable fast compared to, say, the 8MHz 68000 found in the original Macintosh (let alone a 4.77MHz 8088), but a pain in the bum to program.

    The MAX10 FPGAs are quite nice.  They cost a bit more than the Lattice iCE40 ($11.06 for the cheapest useful part vs. $5.51) , but they are much faster (450MHz vs. 125MHz) and have much more internal RAM.  The cheapest iCE40 parts have none, but above that they have between 64 and 128 kbits.  Which is enough (for example) for colour lookup tables and video FIFOs.

    The cheapest MAX10 has 96 kbits, so it's in the same ballpark.  The next model MAX10 up, costing $17.12, has 1248 kbits, nearly 10 times the largest iCE40 model.  Also, the MAX10 is configured in internal flash, so you don't need an external SPI ROM or to configure it from the CPU.

    I'm not keen on using an FPGA if I don't have to.  They're neat, no question, and can do things that would otherwise soak up a ton of CPU time, but it takes a lot of effort to get even a modestly complex design working right.

  • The cheapest and easiest way to add HDMI output to a device might well be a Raspberry Pi Zero...  But the HDMI association would probably insist you pay for a license anyway.

    The Pi Compute module, though, is interesting.


Video of the Day



Watching experts struggle with things that should be simple is a whole new under-explored genre.  This time other Linus doesn't drop a $10,000 CPU though.


Picture of the Day

http://ai.mee.nu/images/A1600-1.PNG?size=720x&q=95

Well, it's a design for a possible prototype.  Fully routed, but it doesn't let me directly get at the CPU's video and networking capabilities.


Disclaimer: F the PGA.

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Sunday, July 21

Geek

Daily News Stuff 21 July 2019

We've Got It All Edition

Tech News

  • Only two things are certain: The death of Stadia, and taxes.  (One Angry Gamer)

    And we're trying to do something about taxes.

  • NASA's Orion crew capsule is officially complete.  (Tech Crunch)

    A test flight to lunar orbit is planned for next year, using the SLS.

  • SpaceX's Starship is expected to have a test launch within 3 months.  (Tech Crunch)

    Their StarHopper had an engine test a few days ago that ended abruptly due to anomalous fuel conditions.



    The Hopper seemed to be fine afterwards, at least outwardly.  Looked spectacular though.

  • HDMI is a pain in the bum.

    If you want to output a VGA signal, you can do that with a few TTL chips and a handful of resistors:



    Or a PIC driving an SPI serial bus and a handful of resistors:



    Or an ESP32 with some internal timers and a handful of resistors:



    But if you want to do HDMI, well, first you have to pay $5000 to the HDMI Licensing Association.  Second, whatever pixel clock you are using, the HDMI clock is ten times as fast.  You can just barely get that out of a low-end FPGA like the Lattice iCE40, using DDR signals, if your pixel clock is no more than 25MHz. 

    (And I'm not sure whether pixel-doubling tricks work with HDMI, so that limits you to 640x480 as the one and only available resolution.)

    You can buy DVI interface chips, which have exactly the same video signalling as HDMI at up to 1080p (you can get a DVI<->HDMI cable for $6 and it will work perfectly as long as you don't go above that resolution).  There's no license fee, no NDA, and no royalties.  It's still basically impossible to generate the signal yourself, though.

    You could use a Texas Instruments TFP410, but if you're working with parts like that Amiga-on-a-chip (the STMicro H750) it would be the most expensive component in your entire build.  480MHz Arm microcontroller with 1MB RAM and onboard blitter and LCD controller, $10.91; DVI transmitter $11.24. 

    (A$, qty 1.  Volume prices in US$ will be far lower, but I need to buy one of them to start with.)

    The NXP TDA19988 is described as an HDMI transmitter but would be equally happy being wired to a DVI socket, and at $7.94 would at least be only the second most expensive component.  For comparison, a DisplayPort to VGA adaptor, which is actually complicated, costs $3.00, and a three-port HDMI switch costs $2.40.

    It's at least an option, probably.  And it's cheaper than a proper video DAC that will run at 1080p60 resolutions - the cheapest one I've found is $9.80.  I wasn't planning to use one of those, though;  15 bit colour can be done well enough with cheap 0.5% resistors.

  • Speaking of Amigas-on-chips, I found another one.  This is the Renesas RZ/A1L.

    Performance is very similar to the STMicro H750 - it's a 400MHz Cortex A9 vs a 480MHz Cortex M7, and the A9 is 20% faster than the M7.

    It has a blitter and a video controller, and all the usual periphery like counters, timers, DMA, PWM, Ethernet, USB, SPI, SPDIF, and SD/MMC.

    The big difference is that this is a microprocessor rather than a microcontroller, meaning that (a) it has no on-board flash at all, so it has to have an external boot ROM to do anything, and (b) it has 3MB of RAM vs. 1MB on the H750.

    Oh, and it seems to have four independent playfields - four graphics layers - compared to two on the H750.  So you could have a static game background, a background sprite layer, a static foreground, and a foreground sprite layer, with all the hard parts done by the hardware.

    Which makes it more like the Amiga 1200 than the Amiga 1000. 

    It also has several siblings - the A1LC with 2MB RAM, the A1M with 5MB, the A1H with 10MB, and the faster A2M with 4MB and hardware sprites.  (But only 16 of them; I checked.)  They're not all pin-compatible, though the A1M and A1H are.  And they're available in QFP, unlike many higher-end chips which are only in BGA and a pain for small production runs.

    The A1M, A2M, and A1H also drive two displays simultaneously.  Not sure if they can drive two displays with four graphics layers though.  And it looks like the display controller can do the pixel-doubling and line-doubling that I need without having to constantly fiddle with control registers.

    The RZ/A1LU starts at A$23.52 qty 1.  That's twice as much as the H750, but that chip is an anomaly; the STMicro F469, which has 384K of RAM and runs at 180MHz (but does have 2MB of flash) costs $23.46.

    The 5MB part is nearly double the price, though.  Avnet supposedly have it cheaper, but their search function is bugged all to hell right now.  But hey, a dual-display 400MHz Amiga-on-a-chip for about US$28 is not exactly bad.  (Price does not include two of those darn DVI transmitters.)

  • You also need a license for SD cards, it turns out.  If you want to build something that SD cards can plug into, you need to pay $2500 a year.  Good old MMC, no license fees.

    Wonder why all those cheap Chinese gadgets have TF cards - "TransFlash" that look and work just like micro SD but technically aren't?  There you go.


Video of the Day

It was thirty years ago today.  Approximately.



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