Possible cheap alternatives to VBXE?

[Rybags]

How about another cheapie...

 

something that's a plug-thru for Antic and snoops the ANx bus, and decodes writes to GTIA.

Provides that missing bit of luma information that most modes lack - would of course also need mods to the early stage of the video circuit.

 

It'd only work for Playfield though, not PMGs. Also some logic would be needed such that it works when PRIOR gets switched to GTIA modes.

 

Additionally, could provide for automatic interlaced video generation (similar technique to my software method but without the needed CPU intervention)

Edited November 30, 2013 by Rybags

[candle]

Gary,

But your mode works reliable only on CRT monitors/lellys - can't get reliable results on scan converters, or LCD tv (50/50% for LCD depending on brand and model)

besides, it would required doing gtia adaptation in some kind of cpld/fpga cheap, and cheapest but capable of doing so would be machxo2-2200 ($13 or so) plus some glue logic

it would not be reconfigurable, it would not have any ram (although it could have) and in the end of the day, price diffrence could be similiar to what vbxe costs

my guess would be it could be $30 cheaper at most - that would be 2 meals at mcdonalds if you can say they offer meals

[ClausB]

GNBN:

 

GN: Teensy 3.0s were on sale so I got two.

 

BN: I had read the wrong data sheet. 3.0's I/O is not 5V tolerant so it won't work in a cart. I do have other projects in mind for the two.

 

GN: Teensy 3.1 is out and it is 5V tolerant, plus it's faster and has 64K RAM!

 

[gozar]

Coming into this late, and just thinking out loud...

 

I don't understand the hostility to the Raspberry Pi as a peripheral to the Atari. The GPIO pins are not 5V tolerant, so they would require some additional work, but I think you could hook a RPi up to the PBI. Once there, you have an easily programmable device to be whatever you want (although it appears there would be additional work to be done to properly mirror the Antic chip).

 

Options that I'd like to see (but would still keep it an Atari):

• Storage device: should be very quick over the PBI
• Terminal app for the 8-bit to access Linux on the RPi (this doesn't ruin the Atari feel, it's just like if you are using a term program to access a BBS).
• Network access - networked games and BBS access. A reworked R: driver that allows you to perform http gets and puts for API services. Access Twitter, for example.

Then move on to graphics and sounds (although then you are beginning to step outside of being an Atari)...

 

I think networking would be very useful (especially with a wifi adapter in the RPi). The RPi Model A is $25, hopefully it could be connected to the PBI for a total cost of under $40. Thinking about it further, it might work better as an SIO device if it's not being used for graphics and sound.

 

Or maybe I haven't been keeping up with things and these ideas have already been shot down... :-)

[ricortes]

Things may have changed but the RPi I bought didn't come with a power supply, box, keyboard, SD card, or OS. Farnell also gouged quite a bit, something like $15 S&H. Only video out was HDMI or really bad composite. I also got gouged on the HDMI cable, I think I spent another $15 on it. Linux or if you go for it Android OS really need $15 worth of mouse too. Total cost to get a model B up and running w/o monitor or box is over $100. You end up with a rather anemic 700 MHz single core Arm processor trying to run Linux. Only way to access the internet is through the Ethernet port.

 

For comparison, I am typing this on a 1.8 GHz IBM Thinkpad with Windows XP I picked up for $20. It didn't have a power supply but I found one for $3.

 

That is pretty much the rub. Should'a could'a would'a put VGA and Wifi on the RPi. Remember the title of the thread is 'low cost' so compared to the RPi, VBXE looks like a bargain. You could get a really nice used laptop for what a RPi costs and have extra features like DVD and Wifi built in. It isn't that the RPi doesn't work, it is to get it to work costs as much or more then other options. Add in the interface circuitry as you noted and tack on another $25.

 

I haven't fooled with mine for quite a while. My son saw it and it went for a walk. I did ask for it back but returning it isn't one of his priorities. As much as I remember it was a pretty solid device with crappy composite, HDMI for a real monitor. The stereo out sucked, lines too close to address lines or something so huge amount of noise making it unfit for use as an MP3 player. Reminded me a lot of running Windows 95 on a 16 meg system with a 120 MHz processor.

Edited December 27, 2013 by ricortes

[gozar]

I'm not looking at one to replace the 8-bit as much as a peripheral for the 8-bit. Total hardware costs for using it off of the SIO port would be less than $50 (case, adapter, Model A RPi, misc. cabling). Everything I mentioned could be done with an SIO2PC cable and a computer, but that takes up a lot of desktop space.

 

The Altirra emulator looks pretty nice to try if you do pick up an x86 computer, just wish it ran under Linux. :-)

[candle]

count pins on gpio header on the rpi - let me know if you're anywhere near 50, 40 at modest

if not near that count, that the interface will cost more than rpi itself

i was using rpi as my only window to the world when i had no pc on the location i work, so i know what it's capable of, and i'm not very impressed

700mhz arm 11 is in terms of preformance near 175mhz x86 system, and this was ages ago

software quality is another issue bringing it down

 

in terms of cheap alternatives for vbxe, altirra is your only option (provided that you HAVE a PC)

[ricortes]

I'm not looking at one to replace the 8-bit as much as a peripheral for the 8-bit. Total hardware costs for using it off of the SIO port would be less than $50 (case, adapter, Model A RPi, misc. cabling). Everything I mentioned could be done with an SIO2PC cable and a computer, but that takes up a lot of desktop space.

 

The Altirra emulator looks pretty nice to try if you do pick up an x86 computer, just wish it ran under Linux. :-)

I make the cost of a minimum RPi at $25 for the RPi, $13 for the SD card/OS for the 4 gig Farnell one, and $15 S&H assuming they are still saying the RPi weighs 4 lbs so they can gouge you on shipping. Heck, they may even say their SD cards weigh another 4 lbs, lying crooks. Anyway, $53 w/o any of the parts necessary to do anything Atari with it. I think even the Apple workers at Foxcom get $.75/hour so the interface would have to cost something.

 

It's an expensive hobby if you do anything out of the mainstream. Worthwhile and interesting, but expensive. I am preaching to the choir here.

[Chilly Willy]

I think a cart that is part SD interface and part graphics enhancer is the way to go. The cart would provide lines of graphics and sprites at a set address, but to go a little further, have it maintain a couple layers internally for a nice parallax background. Since better graphics requires more data, having a built in SD card interface would go a long way towards providing the extra data. Maybe have it provide audio data as well as graphics (streamed PCM from SD card to the POKEY, e.g.).