Zikzak - crummiest 8bit console/computer ever .. but I'm making it!


That looks pretty neat; I might try hacking somethign together .. I was fiddling with ESCs and so on (or making my own..) for a quadropter project, but quickly realize d(and from _everyones_ online advice) that I'd be crashing it into my kids and carving their eye sout, I'd best put it on hold a bit :) (well, till I can afford it.. buying kits or ARFs is cheaper than building yourself, but wheres the fun in that? HobbyKing in Hong Kong has really good prices...) -- I've got a gyro chip that does tilt, rotation, elevation, the works, but has a freakish API, so one day I'll see about pulling data out of it and build a self balancing copter or car or something....

RL been busy lately, with birthday parties and Christmas parties and so on already .. but once I get ZIF sockets i nthe post from China (any day now I'd hope, been 5 weeks+), I'll get to the z80 business. I just don't want to be pulling the eeprom in and out of sockets/boards all day long, the legs will pull out.. and it was pricey-ish and I only have 1 or 2 of them :)

jeff
 
skeezix said:
[…]RL been busy lately,[…]
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Your life is far busier than mine. But I still don't find free time to mess with electronics, game programming etc.  :(  


Quadcopters (and helicopters) are really interesting, but can be pricy (2/4 motors, complex electronic, …).


That's why I'm more interested by planes (they can be quite cheaper and are far simpler).


With the "Flack" (Flying hack), the great thing is that even if you crash it, you just have to retrieve the board with electr-ic-onic parts and make a new airframe out of cheap materials :p


The really pricy part is the transmitter/receptor pair (whatever device you make), I'll probably invest in a hackable one (turnigy 9X, FlySky FS-TH9X, as they're using Atmel µC as brain ^^). Even if the hardware is a bit lower quality, it fits better with my mindset. And with 9 channels, you can control quit a few accessories  ^_^
 
For quadcopter stuff, I was rolling my own electronics (balancing etc); I didn't go so far as to make the ESCs (bunch of H-bridges etc), though not too hard.. I'm just sort of intimidated by higher voltage yet :)

But yeah, shoudl buy a cheapo ESC (Hobby King, Turbigy ftw) and cheapo motors (Turnigy again there.. 1/4 the price they are here!)

But I'm with you.. simple planes.. theres awesome kits for $70 and such, crazy; more expensive to roll your own, but a nice simple flying wing is pretty cheap. All you need is one servo (rudder) and control elevation with speed throttle on the motor.. piece of cake. Maybe in Jan/Feb...

jeff
 
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We all have stomach flu here, big old disaster :)

I did manage to cram the robot car gutts into a plastic box so the kids stop ripping it apart .. much more robust now; car can roll onto its back and not get damaged. I need to recode the control system or add some more controls, so I can do fast speed changes, maybe do some stair climbing..

For zikzak though, still waiting on the PSG sound generators and ZIF sockets and some bits from China .. been like 7 weeks or somesuch now, taking forever; I assume holiday rush is blocking things up.

jeff
 
I stumbled across this bad-boy chip on the TI website, and ordered a few free samples:

http://www.ti.com/product/tfp410

Looks like a "all sorts of shit" -> DVI/etc chip

I need to go over the datasheet, see what capabilities it has .. but doesn't look like it itself has a framebuffer, so not going to help me here; looks like you use one of these on the sender side, and another similar chip on the receiver side, and this does the encode/decode handling.. but not resolution shifting or containing the frame or anything. Shucks.

jeff
 
The problem we've always been facing with the zikzak designs in video; I've ben trying to keep costs low, and limit the number of techs at play.. but the little avr microcontrollers just aren't cut out for high speed and large memory needs of a good VGA system; I do have some higher speed but even lesser memory chips around. Most of the cheap 'next step up' chips are the higher end ARMs which tend to run Linux.. and I really don't want to run Linux on this guy (since 1 - its sort of stupid to write your own mini OS and machine, and have a full linux environment sitting beside it to do video, and 2 - its slow to boot etc; I like the instant on I have now; and 3- see 1 :)

But I've not really gone looking around _Too much_ at other chips; think I will..

I did briefly look at some of the Parallax Propeller type chips, which are sort of neat.. but also low RAM, and using silly languages and so on.

I've got some MPS chips around, but didn't look much into them; I shall hit up the sites and see what other stuff TI has, etc.

Theres got to be a micro that is either faster (say 100MHz or more) or ha more RAM .. or both, that is not also running Linux or some big wanker chip with 300 pins; I want a little micrcontroller, mybe 64-100 pins, thats a little faster and a little more RAM.. damnit :)

.... but I've been itching to play with FPGAs more; I've done a little reading of some Verilog and VHDL, and I have the Firebee here (an FPGA based Atari ST machine, of sorts.) The MiST looks sweet as well. But I'd ratehr go bear bones FPGA.. not even a dev board if I can avoid it (and they're expensive, usually for some reason.. though theres a few $50/$75/$99 jobbies around..)

Some cheap Xilinux FPGAs are $5-$15 though.

You know, a FPGA video chip would be pretty sexy; they're suaully fast enough to spit out VGA, and do have a bit of RAM, and you can flash them to do whatever your bidding is.. not quite a mcu, but flash your own utility chip? Coudl do all sorts of shit with that..

... okay, let me consider if I can get an FPGA in there and simplify the design.

My whole problem ahs been the chiosp not fast enough to work with RAM, while doing VGA, without killing the performance on the 'cpu chips'; but with an FPGA, I can probably do it, and still maek it 'just a gpu', without cheating..

... fun fun :)

jeff

I suppose theres mega AVRs too.. I've always just ignored them, heard they stunk up the place. And xmegas.

More research time.. hopefulyl all my kdks are getting healthier.. this 2-3 weeks of back to back sick and up all nights been killing us.. but I want to get back to hacking! :)
 
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Or should I just build a NTSC/PAL tvout?

Those are easier .. a pita for sure, but easy to do on low speed; could have that up and going in full colour like a Spectrum or Vic-20 no problem.

But the holy grail is VGA, damnit :)

jeff
 
skeezix said:
Theres got to be a micro that is either faster (say 100MHz or more) or ha more RAM .. or both, that is not also running Linux or some big wanker chip with 300 pins; I want a little micrcontroller, mybe 64-100 pins, thats a little faster and a little more RAM.. damnit :)
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ARM Cortex M3 or M4 even? The STM32 range seems to be quite popular these days with projects that need just that little bit more oomph than an AVR.

Edit: http://www.artekit.eu/vga-output-using-a-36-pin-stm32/ It's the new black! :)
 
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Great tip thanks!


Arm chios are scary from the amount of documentation.. But they dont look too bad to bootstrap. Of course fpgas are rediculous too :)


I don't mind working in tqfp64/lqfp64 ..


I amy see if I can acquire some! At 120 MHz I could probably interleave memory access .. The things have memory for framebuffers .. Fast enough to drive VGA colour pretty high res..


Sounds perfect :)
 
Still - annoyingly - waiting for the sound chips and some buts.. So roadblocked. Well and stuck with sick kids - pinned under one now :)


But I'll put a sample request or small order in .. With luck will have some sound chips, fpgas, mps, stm32, and more to fiddle with .. Fun :)
 
Kids climinb all over me, so hard to think straight..

Xilinx FPGA (Spartan 3 say) in question aren't too bad.. $11 at digikey; the programmer side will take some looking into.. can you just use an SPI or JTAG cable, or need oyu some Fancy Shit? They recommend the Platform Cable 2, which is about $230 at digikey, and has all sorts of stuff in it. (Maybe it has a lot of good features, in system debugging etc..) .. but thats a pretty big outlay for me.. $230 for cable, plus say 3-5 of the chips .. boom!

So I ordered some samples of PIC32, and some ordered some STM32's. I've already got a PIC programmer (Pickit3 and Pickit2), so good to go; ordered a ST-link 2 cable for the stm32.

Digikey is fast, hopefully get them early next week so have them for downtime after Xmas..

Can't wait! This c9oudl really help redesign the video side of zikzak.. this using avr8 for video has been a nightmare :)

jeff
 
Cool! I might want to order that ST-link 2 debugger thingy too. It's dead easy to get your firmware on an STM32 (there's a built-in serial/usart bootloader, an FTDI cable does the trick as well), but the ability to do some debugging is always nice.

I've been playing with a "Mojo FPGA dev-board" from embeddedmicro.com a little bit. That uses an ATmega32U4 to configure the FPGA itself (connected through SPI I think, but not sure). The ATmega32U4 connects with USB to your computer. JTAG is also broken out to the pins. A cheap and easy way to get started with FPGA's, but unfortunately the Xilinx tools are closed source. That proves to be a bigger mental barrier for me than necessary perhaps, but the barrier is still there. The ISE design suite felt like a shitstain on my Linux box a little bit, and I didn't install it on my new PC.

That said, I also have Steam and Eagle installed so I better get off my double-standard high horse and install it again. :)
 
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I use Ragle as well .. Its a great 1985 style app .. But Free / OSS is worse.


Altium looks nicty but wha the eff $$..


I can sort of see why fpga tools are closed due to competition but it sure holds back all these platforms .. If tools were convenient and approachable they'd sell more..


I think after Xmas I'll nab some fpga action but not today..


This stuff is way too fun :)
 
Documentation for these ARM chips has always been goofy imho; no free time hardly yet, kids still a sicky mess (and wife too again..), but getting there; need to pick up a pile of caps to stabalize power into the STM32 F2 Cortex-M3 I've got here now; found the "CMSIS" headers for it .. so at least I've got the ARM-standard STM32-F2-specific headers to work with; I've got some TQFP adaptors, so need to make sure they have solder mask and see about getting a chip onto the adaptor, and see about proving the programmer works, nailing down the linker scripts etc.. getting a LED to blink. Once I can blink a LED (should be easy), and once I can get some timers going .. it'll be all I need to toy with VGA.

ie: I'd like to do it all interupt/timer driven for hsync, vsync, and then do pixel fill triggered there .. on the slower avr8s theres just too much cost to the interupt context switching, and not enough performance at all.. but these F2 are 120MHz so I'm hoping that should be enough; ie: I forget, but some of the VGA modes are like 36MHz pixel clocks and such .. so if I can run 72 or 108 it makes a nice even multiplier; but even at 120, a nice timer should get me close enough to one or more modes to work. Need to look up the PLL multipliers for this sucker..

The F4's look pretty swank and peek out at what, 180MHz (!), but they're also the 100+ pins; I've got I think 1 spare TQFP100 adaptor to DIP, but bleh.. thats just too many pins. If I keep this as a pure VGA handler, it doesn't need much pins.. just performance. The F2 has a pretty fast clock (120MHz and lower), and also comes in the 64 and 100 packages. Too bad no DIP packages just to make life easy..

Mind you, it should have performance left over, so could be the IO chip as well.. in which case pins are nice to have (joystick, speaker, I/O bus to z80, etc.) We'll see.. if I can get it alive at all, then will plan it out.

(and yes, as in all things.. the chip could run a whole computer itself, but as always with zikzak.. the goal is to make an essentially old school machine, and use a modern chip only as needed)

jeff

Ho, this looks like a neat chip; low pincount DIP, but 50MHz ARM. Cute :) http://www.digikey.com/product-detail/en/LPC1114FN28%2F102%2C12/568-10143-5-ND/3430860?WT.z_cid=ref_octopart_dkc_buynow
 
I use the LPC1114 in my SCSI card reader project, although the LQFP48 version. It's a little quirky to get started with, but otherwise nice.
 
Spent the last couple nights wrestling with wonky network here in the house.. love how that just suddenly happens :/

Readying myself mentally for attacking the Cortex-M3 I've got here.. LQFP64 (0.5mm version) .. you can barely see those pins right :eek:

At least this round I've got a microscope to post-inspect with, and a vacuum de-solder station; should make recovery doable in case of unwanted pin bridging..

Maybe tomorrow (though thats Christmas Eve..) I can get time to take a shot at it, and start up testing. Picked up a big stack of crystals and capacitors today, as the power needs for this F2 seem a little funky.

jeff
 
Finally some action in the packages,.

ZIF sockets received, so now working on the Z80 ROM is looking feasible. Took them some 10+ weeks to arrive.. uugh!

Still waiting for the AY-3-8912 audio chips.. but given I ordered them just a couple days after the ZIF sockets, sort of hoping they show up this week *fingers crossed*

Tempted to order a hot-air rework station (cheapies are like $60, decentish ones are $100+) but I'm sort of feeling wallet-burn from Christmas so best hold off; I'll do the TQFP STM32's the traditional way and hope for the best; got 5 of 'em :p Probably take a run at those tues/wed .. I'm really looking forward to sorting out their bootloader and all that, and getting VGA coming out of them. VGA protocol itself is not too hard now that I've done it so many times, so once I get basic dev env working on the STMs, it should be short work .. we'll see :)   After that, can start redoing the CAD work and check pins.. is this going to be now be Z80+STM32, or do I still need an avr8 in there as IO chip? We shall see... but imagine, z80, avr, and stm all on there.. 3 diffferent systems to code for :p

... and theres babies waking again.

Gods, been like 2mo since I had a clear night :/

jeff

Course, I still totally want one of those Xilinx FPGAs.. found a cheap jtag programmer for em, but the dev proto boards are still expensive (but come with all sorts of nifty addons.) One of these months I'll just order some Spartan 3 chips and go to it :p then can roll own vga right at the gate level :)
 
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