David_P

As I recall from seeing it at the Toronto Atari Fest 30 or so years ago: A board with a '816 CPU with extended RAM, built in SDX, R-Time 8, Basic XL, Action, MAC/65...

Sparta 3.X uses RAM under the OS ROM; so does TBXL.

Which lines are you using?

First plot: Food (river) Second plot: Energy Third plot: Energy (preferably adjacent to prior plot) Then go wild on Crystite, with potential to buy plain land plot adjacent to food (river) plot for additional food production. (Nine times out of ten, other people will conveniently over-produce Smithore). And make the computer run up prices on food and energy - also buy out the store on those to make your holdings more valuable, and force the computer to drive up prices. I'm not saying that in a four player game my friends have, on occasion, physically restrained me from participating in auctions because I created artificial scarcity. Not saying it didn't happen, either...

Selling to the store, in theory, depresses market prices (assuming that the market then holds more than is needed for the colony).

Some odd additional wiring - looks like PB1 on the PIA is tied to ground?

With paddles you still require at least one joystick. For the auctions and land grant, people use their own controller. For outfitting MULEs, hunting the Wampus etc, the joystick gets passed around. So, on an XE/XL, one joystick and a pair of paddles lets you have three players (plus one computer).

Suggests that it's using ANTIC banking for the screen display.

Nice - I see there's both an external power, plus PBI power.

You can roll your own https://ataribits.weebly.com/tk-ii.html, or buy a PS2 to XEGS adapter https://thebrewingacademy.com/products/tk-ii-xegs-s-ps-2-for-xegs-keyboard-replacement

PMG are independent of the underlying playfield.

There was a similar table in ANTIC, except it was sorted in numeric order, and also included the ATASCII symbols - useful for some disassemblies. https://www.atarimagazines.com/v3n9/OP_CODE_FINDER.html

A rank amateur here - but if EXSEL is asserted, wouldn't that override any PORTB bit 7 issue?

No, it is another protocol, originally developed for the Spectrum. https://atari8bit.net/projects/software/fujinet-tnfs-server-image/ http://spectrum.alioth.net/doc/index.php/TNFS_server

If you have a 65xe with ECI, then there are products such as the Turbo Freezer which are plug and pay for battery backed expanded RAM.

I think we all know that the only logical replacement for SelfTest is a game that fits in the 2K of ROM.

Also might have an amusing crash, if run from RAM below the OS.

SDX will run on a 400/800; but you need either expanded RAM or a very stripped down CONFIG, since there's no RAM hiding under the OS ROM.

PILOT on an Atari 400 in grade 6. The following summer, we got an 800 with 810, 850 and 825 and BASIC and AtariWriter, plus a box of ten 5 1/4 disks. Bottom pin on the 825 was broken, so we got a 1025 to replace the 850 and 825.

Perhaps D-Bug by Electronic Arts? http://www.atarimania.com/game-atari-400-800-xl-xe-d-bug_1536.html

Split into two nibbles, and you may get two dice from each read.

PILL was a hardware tool to mark RAM as read only, so you could load cracked cartridges into RAM, set the PILL, then run the cart without fear of copy protection. That seems like a homebrew controller to crack carts into files, and to load the cart images without the physical cartridge and then run them.

By default, DOS 2.0S / 2.5 are configured to support two drives only. Adding more drives increases the number of buffers reserved by DOS, reducing free RAM. Text version of the DOS 2.5 manual is at: https://atariwiki.org/wiki/attach/Atari DOS 2/Atari DISK OPERATING SYSTEM 2.5 Manual.txt PDF version (not certain if it has been OCR'd)) is at: http://www.atarimania.com/8bit/files/Atari_DOS_2.5 _1050_Disk_Drive_Owners_Manual.pdf

Certain vectors in the OS ROM are not supported, and changed between the various iterations of the OS. This could be a case of using a function whose location changed between the 400/800 and XL OS ROMs.

One of the most useful single page references for the Atari I ever found - Dec, Hex, Char and OpCode for all official 6502 op-codes, from Antic 3/9. https://www.atarimagazines.com/v3n9/OP_CODE_FINDER.html