David_P

Apparently my google-fu is weak, and I was unable to locate the pinout for the standard 24-pin ROMs in most Atari carts. Anyone have it handy? Or can point me in the right direction?

For me, 7.16mhz with 512K would be more than enough; perfect is often the enemy of good enough.

Bob: There had been mutterings about a possible production of boards for XL/XE systems - any news on that? I'm still very interested.

THe socket above the OS is for BASIC; probably upgraded to BASIC C.

Main system: 800xl, 256K RAMBO, FTe Sweet 16 65816 board, SDX 4.22 / SDX 4.41, XF551, SIO2PC cable Others: 800xl POKEY 800xl CSS dual OS (Translator / 800xl) 800xl stock, 1050 800 (48k) stock XEGM without keyboard 850 interface Graphix AT interface Old EPROM programmer - joystick interface, forget the name

Thanks! Excellent work. I found an online vendor selling I2C boards for around $8 each for both a battery-backed RTC and a flash drive - ships with 16K, easily upgradeable to 256K by swapping out the ICs. (www.futurlec.com - slow shipping, but it's to be expected when it comes from half way around the world). I'm looking at writing a Z: driver for the RTC (DS1307), and possibly a disk handler (128 byte sectors) for the remainder. More to follow as time permits...

There's an XEP-80 driver for SpartaDOS X; and there's Atariwriter 80 out there as well (MyAtari is liquidating their holdings of it, as they've sold their last XEP-80).

Thanks for the quick replies. I'm looking at bit twiddling on a joystick port, and possibly going to two lines on the Atari (data in and data out) - use two bits on the port, a diode on each to keep things unidirectional.

Anyone have any experience in interfacing I2C ICs to an Atari 8-bit? I'm looking at the joystick ports vice SIO for simplicity. In addition, I2C is supposed to be a multi-master bus; that would suggest it should be possible to share any I2C peripheral between two or more 8-bits.

Don't let the naysayers get you down. If they could do better they would; they can't so they sit on the sidelines and snipe instead. There's a large silent majority that appreciates what you're doing - and doing for love of the machine & community, not for money.

There are already threads on AA discussing Ethernet on a cart - on the PBI would be another option. There are Ethernet interfaces designed to interface with 8-bit systems - see http://microcontrollershop.com/product_inf...roducts_id=1202. Perhaps we need to define a hardware standard for the Atari 8-bit - that will provide HW and SW developers with standards to address, vice everyone doing thier own thing and further fragmenting the market. I also seem to recall a "Project ICE - Internet Connectivity for Eight-bits"; I think that page may still be online, with source code available.

There are some ICs and parts listed under "Hardware" at: www.myatari.com

I have been thinking about this. Assuming a 1K shared RAM (like the CY7C130), would it make sense to have one of the two computers invert the high address bit? That way, you can divide the RAM into two areas - one for each computer to write to. Both Ataris would write to $X000 to $X1FF, and read the other computer's data from $X200 to $X3FF - simplifying the software, as there would be no need for awareness of whether one was a master or slave, or #1 vs #2.

COSMIC BALANCE was the first game I ever broke the protection on - a bad sector, so I used a disk editor to set the seek to zero to get the error (I think - it's been quite some time). I don't recall the name of the first game I downloaded, but I do recall that it was at 300 baud, took forever!!! and then I discovered it was XL/XE only; I was still running an 800!

There were the Disk Emulator Routine and the Printer Buffer Routine; two carts with SIO cables with the SEND/RECEIVE and COMMAND/INTERRUPT lines swapped. ANALOG also had a series called "The Atari Zucchini" that made a printer buffer out of a 400/800, hooked to a parent computer by SIO. I think Nick Kennedy has some source code for a similar thing buried on one of the SIO2PC disks as well - or at least some sort of simple chat between two Ataris over the SIO line. A token ring would impose significant overhead on the systems involved. There is always the Gamelink II mechanism, where everyone's SEND and RECEIVE are tied together; similar problem though in that every computer is constantly watching the SIO lines. Might it be better to build a client/server model? One server, which can differentiate between client #1 and #2 by using both the INTERRUPT and PROCEED lines? Need for a bit of hardware in the interface between the systems. Not as fast as the MultiPlexer, but might be a little more friendly with software, as the clients would think they were talking to a regular disk drive(s) over the SIO bus - no need to replace the OS.

I have both disk and Atari cart versions of Blue Max. In the cart version there's the DL reset when you bomb your own hanger. As I recall, once I got the cart I tried the same stunt, and nothing untoward happened. Either $D20A had the same value as SDLSTL, or someone at Atari inserted some NOPs into at least some of the production run.

There were a number of techniques to emulate 80 columns on a bitmapped screen. Scrolling over a wider screen was one; hi-res screen was another, my personal favourite was "Flickerterm" which uses a narrow character set on a normal screen, then flips between two screens offset by 4 dots every VBLANK; uses less memory (1k charset + 2x 1K screen) that the hi-res screen (8k) and is also more responsive.

I forget the name of the store, but it was in Decarie Square in Montreal. One Atari 800 was running an early demo; another had the owner playing Protector. I was hooked. A year or so later my family got an 800, 810 drive, 850 interface, and a defective 825 printer (one of the pins didn't work). So we got a free "upgrade" to a 1025 printer instead.

Why not a 1200xl? There weren't any on when I looked. And I'm not looking at multi-processor; rather, tis way I'll have one stock 800xl, one with the CSS switchable XE/XL and 400/800 OSes, one with the Sweet16 from FTE (with 256K RAM), and finally, the "new kid on the block" with the 7.16 65816. Plus the stock 800. Plus the XEGM. So, as you can tell, I've started downsizing...

Not that I'm anxious, but I just bought another 800xl on Ebay for this upgrade; that will make 2x 65816 and 2x 6502 800xls.

I've seen a lot of things like this on EBay: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...em=150290646371 Famous last words - it looks like it would be easy to replace the plug with an XE/XL plug, ignore the 12V line, and power an XE/XL. ANyone have experience with such a project, and any suggestions?

Bob: You'd better stop posting. I'm sure all the drool is going to short out my PC keyboard...

Ah, but you can always copy the ROM to RAM and enjoy the faster speed - though you are correct, it may be necessary to re-write SIO code to maintain compatibility. And to Bob the Builder: On the 130xe you can have Antic and CPU accessing different 16K banks; I would guess that implementing that feature when using the linear 65816 memory mode would be a challenge (particularly since the PIA bank switching would do nothing). An additional level of complexity in the circuit for minimal return (other than speeding up the Sea of Disks demo)...

It is not intended to speed things up. It just allows new programs to fully utilize the 65C816 potential (i.e. the "native", 16-bit mode). Sorry for the lack of precision on my part - I was wondering about the combination of the board with the OS - and hence the increase due to the faster CPU and, in certain instances, the faster routines in the OS (E: and floating point come to mind as places where you've optimized the OS). Those two factors combined could do great things. I'm also still hopeful that a revised / refined iteration might add RAM - though I suspect creating 130XE compatibility for the first additional 64K may be overly complex. On the other hand, I'm not sure what logic would be required to lock ANTIC into bank 0 while the CPU runs off to play in higher memory ranges. Regardless, even with 64K I'd grab one in a heartbeat.

Jacobus: As the crystal is a fixed frequency you won't be able to vary it (at least, not easily). I'm more interested in the empty sockets - I presume they're for additional RAM? What's the max per socket? And have you tried softloading Drac030's '816 ROM? Does it speed things up? Yummy, yummy, yummy... Steve - put me down for (at least) one...