Ethernet interfacing

[supercat]

I was curious what has been done to interface classic 6502-based computers to an ethernet? It would seem that might have some advantages over USB. Something like a Crystal Semiconductor 8900 would be pretty easy to interface to a processor bus, and while a full-fledged TCP/IP stack would be rather taxing for a poor little micro, a simple UDP handler could be quite straightfoward.

 

Suggested implementation: an EEPROM in the card holds the IP address of a PC or other computer that will be running a classic-computer communications program. Whenever the old computer needs to read or write a certain byte or range of bytes, it sends a packet with the request. The "big computer" would either send an acknowledgement or error packet. Packets that time out would be retried with a "backoff" algorithm.

 

Using such an approach, the RAM footprint on the old-computer side would be extremely minimal. The throughput from that style of protocol wouldn't be very good by modern ethernet standards, but would probably be comparable to anything that could be attained easily via USB.

 

Anyone know if anyone has done such a thing for any of the classic 6502 computers? I know some people have hooked A800's up to the Internet, but I think those projects went the full-fledged TCP/IP route, which would seem to require a bigger RAM/ROM footprint.

[PacMan]

I created a cartridge a while back using the Wiznet chip W3150A and a FLASH for drivers. It is quite cool, a small webserver only requires about 2.5K program memory to work. With this I think it would be fully possible to integrate a new network device to do real LAN networking. Think <LOAD "X:TEST.BAS">. A friend of mine has it now to write drivers, but he is like the slowest guy this side of Moronville (Hej Thomas so that will take a while *hehe*. I'll post some pictures when I get it back.

 

/P

[Garak]

Anyone know if anyone has done such a thing for any of the classic 6502 computers?

 

Yes, the C64 community has done several ethernet interfaces and software ("Contiki OS" and "Artillery Duel" for examples). See here for more information and links to the software and hardware.

 

Garak

[Wrathchild]

Some related discussion here:

 

http://www.atariage.com/forums/index.php?s...amp;hl=ethernet

 

http://www.atariage.com/forums/index.php?s...amp;hl=ethernet

 

http://www.atariage.com/forums/index.php?s...amp;hl=ethernet

 

http://www.atariage.com/forums/index.php?s...amp;hl=ethernet

[pepax]

Anyone know if anyone has done such a thing for any of the classic 6502 computers? I know some people have hooked A800's up to the Internet, but I think those projects went the full-fledged TCP/IP route, which would seem to require a bigger RAM/ROM footprint.

 

Atari: JYBOLAC. Seems abandoned, bud I can be wrong....

C64: RR-Net, ETH64, NET64, TFE, ETFE. Additional links: summary, Contiki.

[Garak]

Additional links: summary

 

See here for more information and links to the software and hardware.

 

Edited January 19, 2007 by Garak

[pepax]

 

Oh my, I didn't realize it took me so much time to finish writing my reply that so many people overtook me in the process.

[danwinslow]

I integrated a NIC via SIO. It worked, but was impractical speed wise. I need a direct memory interface.

[Quadhorn]

I integrated a NIC via SIO. It worked, but was impractical speed wise. I need a direct memory interface.

 

Did you mean "NIC" or did you mean "PIC", by any chance?

 

I know Microchip currently do a 10BaseT ethernet interface on some of the PIC18, PIC24 and dsPIC chips, complete with free TCP/IP stack. 'S'pose it could be fun to fit one in a cartridge; maybe you could provide some kind of parallel interface between the 2600 and one of the PIC's IO ports...? At a push, some kind of 2-port RAM to provide a buffer between the PIC and 6507, so it has space both for the 2600 to form a TCP/IP packet before sending and allow the 2600 to read one back at its own pace afterwards. Meh ..... massively overkill and ends up with the PIC doing everything instead of the 2600 .....

[danwinslow]

No, I meant NIC, as in Network interface card. But that really isn't accurate either, as what I did was to integrate a very small single-board computer ( fits entirely in the 130xe case ) that has a built-in ethernet. The atari communicated to the board via SIO using one of steve's SIO adapters...the board can support ATR images as drives, but it also has a protocol for getting and sending ethernet packets. It works, but beta tests indicate it is just too slow to be practical. I am probably going to re-evaluate in light of the new USB SIO adapter that Steve put out...that might crank the speed up enough to make it worthwhile.

[Quadhorn]

No, I meant NIC, as in Network interface card.

Ahhh .... 'makes sense now. I feel like I should have known.

 

[W]hat I did was to integrate a very small single-board computer ( fits entirely in the 130xe case ) that has a built-in ethernet.

So, still kind of overkill compared to the abilities of the 8-bit's, then.

 

I am probably going to re-evaluate in light of the new USB SIO adapter that Steve put out...that might crank the speed up enough to make it worthwhile.

I can't say I've looked at it, but is that likely to make it that much faster? It's still limited by the speed of the serial link. Would a feed-through ethernet cartridge (allows you to put a program cartridge on top for use with different programs) be entirely unfeasible? I suppose at least the USB connector would be cheaper than an edge connector for a feedthrough cart.

 

On the other hand, looking at the USB SIO card, you'd have two main choices that I can think of:

 

1. Use the SIO card to connect the Atari to the PC, then program something to allow the Atari access to the PCs ethernet; requires no further hardware

2. Build a stand-alone ethernet adapter that plugs into the USB SIO, but that would have to have a USB Host Controller chip on it to talk to the USB SIO's USB Peripheral Controller chip (no small beasty to deal with, even with all the help and reference designs), coupled to the ethernet chip.

 

Btw, looking down the thread, it occurs to me that I have the A2600 on the brain at the minute, but that's not what you're aiming this at. Maybe I just like the idea of an A2600 online. A simple text browser...? Use the 48-pixel sprite trick for selected images...? Back to sanity, was it just the 130-XE, or did you have other Atari machine(s) in mind as well?

 

I was curious what has been done to interface classic 6502-based computers to an ethernet? It would seem that might have some advantages over USB. Something like a Crystal Semiconductor 8900 would be pretty easy to interface to a processor bus, and while a full-fledged TCP/IP stack would be rather taxing for a poor little micro, a simple UDP handler could be quite straightfoward.

 

...

 

I know some people have hooked A800's up to the Internet, but I think those projects went the full-fledged TCP/IP route, which would seem to require a bigger RAM/ROM footprint.

The PIC method might have the advantage that they come in FLASH flavours and handle everything themselves. On top of possible direct memory access providing higher bandwidth. The Atari would only have to deal with what ever interface you specify between its processor and the PIC.