***¢ Atari 8-Bit Computers¢ Frequently Asked Questions List¢ on the INTERNET-Revised 28-Oct-95¢ (This info was sent to me by TOM SMITH¢ an OHAUG member. THANKS TOM!)¢ (Ed. I have tried to give you a small¢ taste of the INTERNET info avalable,¢ through this article. I have had to¢ format it to fit th newletter. A.P.)¢ ¢ Additions/suggestions/comments/correct¢ ons are needed! Please send to:¢ URL:mailto:mcurrent@carleton.edu¢ UUCP:¢ ...!umn-cs!ccnfld!mcurrent¢ Cleveland Free-Net: aa700¢¢ Copyright (c) 1992-1995 by Michael D.¢ Current, and others where noted. This¢ file may be reproduced, in whole or in¢ part, so long as the content of that¢ portion reproduced is not modified,¢ and so long as credit is given to this¢ FAQ list or its Maintainer, or the¢ author of that section reproduced when¢ given.¢¢ The Atari 8-Bit Computers Frequently¢ Asked Questions List was created to¢ provide answers to many commonly asked¢ questions found in the Internet's¢ comp.sys.atari.8bit/Info-Atari8¢ Digest/INFO-A8 discussion group. It¢ is in a constant state of development,¢ and comes with no guarantees. If you¢ see any problems, I need to hear from¢ you!¢¢ Where to get the latest copy of¢ the 8-bit Atari FAQ List ---¢ The home of many FTP archive sites,¢ automatically updated monthly: ¢ URL:ftp://rtfm.mit.edu/pub/usenet-by-¢ group/news.answers/atari-8-bit/faq¢¢ The World Wide Web hypertext version,¢ automatically generated monthly:¢ URL:http://www.smartpages.com/faqs/¢ atari-8-bit/faq/faq.html¢ URL:http://www.cis.ohio-¢ state.edu/hypertext/faq/usenet/atari-¢ 8-bit/faq/faq.html¢¢ WWW "flat hypertext" versions,¢ automatically generated monthly:¢ URL:http://www.cs.ruu.nl/wais/html/na-¢¢ dir/atari-8-bit/faq.html¢ URL:http://www.lib.ox.ac.uk/internet/¢ news/faq/archive/atari-8-bit.faq.html¢¢ Usenet newsgroups where this FAQ list¢ is automatically posted monthly:¢ URL:news:comp.sys.atari.8bit¢ URL:news:comp.answers¢ URL:news:news.answers¢¢ You can also get the latest version by¢ e-mail.¢ URL:mailto:mail-server@rtfm.mit.edu ,¢ message says: send¢ usenet/news.answers/atari-8-bit/faq¢ quit¢¢ Finally, you can always ask me for a¢ copy at¢ URL:mailto:mcurrent@carleton.edu¢¢ ------------------------------¢¢ Subject: 0.1) Table of contents¢¢ 0.1) Table of contents¢¢ Introduction¢ 1.1) What is an Atari 8-bit¢ computer?¢¢ Usenet¢ 2.1) What is comp.sys.atari.8bit?¢ 2.2) What is comp.sys.atari.announce?¢ 2.3) What is comp.sys.atari.advocacy¢ 2.4) What is¢ comp.sys.atari.programmer¢ 2.5) What is comp.emulators.misc?¢ 2.6) What is¢ comp.emulators.announce?¢¢ E-Mail¢ 3.1) What is the Info-Atari8 Digest?¢ 3.2) What is INFO-A8?¢ 3.3) How can I retrieve files from¢ FTP sites by e-mail?¢ 3.4) How can I post to Usenet¢ newsgroups by e-mail?¢ 3.5) How can I access the World Wide¢ Web by e-mail?¢¢ Software Archives¢ 4.1) What is the University of¢ Michigan Archive?¢ 4.2) What is the Boston Archive?¢ 4.3) What is the PVV Archive?¢ 4.4) What is the ClarkNet Archive?¢ 4.5) What is the Gatekeeper's¢ Archive?¢ 4.6) What is the QACE Archive?¢¢ Telnet¢ 5.1) What is the Cleveland Free-Net¢ Atari SIG?¢ 5.2) What is the Youngstown Free-Net¢ Atari SIG?¢ 5.3) What is the National Capital¢ Free-Net Atari Users SIG?¢ 5.4) What is the Victoria Free-Net¢ Atari Computer Users SIG?¢ 5.5) What is the Closer To Home BBS?¢ 5.6) How can I access the World Wide¢ Web by Telnet?¢¢ World Wide Web¢ 7.1) What WWW pages support the 8-¢ bit Atari?¢¢ IRC¢ 7.9) What IRC channels discuss the¢ 8-bit Atari?¢¢ Online Magazines¢ 8.1) What is the CAIN Newsletter?¢¢ File Formats¢ 9.1) What's this UUEncoding stuff¢ (.uu, .uue files) all about?¢ 9.2) What is an .arc file?¢ 9.3) Okay, how about a .dcm file?¢ 9.4) What is an .xmo file?¢¢ Emulation¢ 10.1) What 8-bit Atari emulators¢ exist for other computing platforms?¢¢ File Transfer Solutions¢ 11.1) What are the best terminal¢ emulators available?¢ 11.2) Can I read/write 8-bit Atari¢ disks on an IBM-PC?¢ 11.3) Can I read/write MS-DOS disks¢ on an 8-bit Atari?¢ 11.4) How do I transfer files using¢ a null modem cable?¢¢ Storage Media¢ 12.1) What 5.25" floppy disk drives¢ are available?¢ 12.2) How can I use 3.5" floppy¢ disks with my 8-bit Atari?¢ 12.3) What do I need to connect a¢ hard drive to my 8-bit Atari?¢ 12.4) How can I use an IBM-PC as a¢ storage device for my Atari?¢¢ General Interest¢ 13.1) What's the best DOS for the¢ Atari?¢ 13.2) What hardware has Atari created¢ in the 8-bit computer line?¢ 13.3) What are the power-supply¢ requirements for my Atari components?¢ 13.4) What are the pinouts for the ?¢ 13.5) What BBS software can be used¢ on the Atari?¢ 13.6) What version of Atari BASIC do¢ I have?¢ 13.7) What are the Standards for¢ Used 8-Bit Stuff?¢¢ Other Documents of Interest¢ 14.1) What vendors, developers, or¢ publishers support the 8-bit Atari?¢ 14.2) Where is my nearest 8-bit¢ Atari BBS?¢ 14.3) Where is my nearest 8-bit¢ Atari user group?¢ 14.4) How do I use my new or¢ emulated Atari?¢ 14.5) What prominent Atarians are¢ reachable by e-mail?¢¢ ------------------------------¢¢ Subject: 1.1) What is an Atari 8-bit¢ computer?¢¢ In order of their release, the Atari¢ 8-bit computers include the 400, 800,¢ 1200XL, 600XL, 800XL, 65XE, 130XE, and¢ the XE Game System. The 400/800¢ models were first shown publicly in¢ November 1978 and first sold in 1979. ¢ The final machine, the XE Game System,¢ was released in 1987. Atari Corp.¢ officially dropped all remaining¢ support of their 8-bit computer line¢ on January 1, 1992.¢¢ The following text was written by¢ Chris Crawford and appears in De Re¢ Atari (Atari#APX-90008), a book¢ published and copyright by Atari,¢ Inc., 1981-1982. It has been very¢ slightly modified here for¢ generality.¢¢ "The internal layout of the Atari¢ 8-bit computer is very different from¢ other systems. It of course has a¢ microprocessor (a 6502), RAM, ROM, and¢ a (PIA). However, it also has three¢ special-purpose (LSI) chips known as¢ ANTIC, GTIA, and POKEY. These chips¢ were designed by Atari engineers¢ primarily to take much of the burden¢ of housekeeping off of the 6502,¢ thereby freeing the 6502 to¢ concentrate on computations. While¢ they were at it, they designed a great¢ deal of power into these chips. Each¢ of these chips is almost as big (in¢ terms of silicon area) as a 6502, so¢ the three of them together provide a¢ tremendous amount of power. Mastering¢ the Atari 8-bit computers is primarily¢ a matter of mastering these three¢ chips.¢¢ ANTIC is a microprocessor¢ dedicated to the television display. ¢ It is a true microprocessor; it has an¢ instruction set, a program (called the¢ display list), and data. The display¢ list and the display data are written¢ into RAM by the 6502. ANTIC retrieves¢ this information from RAM using direct¢ memory access (DMA). It processes the¢ higher level instructions in the¢ display list and translates these¢ instructions into a real-time stream¢ of simple instructions to GTIA.¢¢ GTIA is a television interface¢ chip. ANTIC directly controls most of¢ GTIA's operations, but the 6502 can be¢ programmed to intercede and control¢ some or all of GTIA's functions. GTIA¢ converts the digital commands from¢ ANTIC (or the 6502) into the signal¢ that goes to the television. GTIA¢ also adds some factors of its own,¢ such as color values, player-missle¢ graphics, and collision detection.¢¢ POKEY is a digital input/output¢ (I/O) chip. It handles such disparate¢ tasks as the serial I/O bus, audio¢ generation, keyboard scan, and random¢ number generation. It also digitizes¢ the resistive paddle inputs and¢ controls maskable interrupt (IRQ)¢ requests from peripherals.¢¢ All four of these LSI chips¢ function simultaneously. Careful¢ separation of their functions in the¢ design phase has minimized conflicts¢ between the chips. The only hardware¢ level conflict between any two chips¢ in the system occurs when ANTIC needs¢ to use the address and data buses to¢ fetch its display information. To do¢ this, it halts the 6502 and takes¢ control of the buses."¢¢ The 130XE and XEGS contain a¢ small additional LSI called FREDDIE, a¢ RAM address multiplexor. According to¢ URL:mailto:sup8pdct@closer.brisnet.org¢ au (James Bradford), "Freddy is a type¢ of memory controller. It takes the¢ address and clock from the CPU and¢ multiplexes it with the appropriate¢ timings and signals to use DYNAMIC¢ memory. Freddy also buffers the¢ system clock crystal and divides it¢ down then feeds that to GTIA. The¢ XEGS has a freddy but it doesn't have¢ the extended RAM. Even if it did, you¢ would still need the chip that does¢ the REAL bank switching. It is a¢ small 16-pin chip (Atari/Best¢ Electronics catalog number CO25953:¢ rev9/page 42). It gets RAS from¢ freddy, the bank select bits from PIA,¢ A14, A15 and the 6502 halt signal to¢ control which bank of 8 chips RAS goes¢ to. A14 and A15 then go to freddy for¢ the address range of the extra memory¢ bank (or normal address range with no¢ bank switching). The ANTIC/6502¢ select bits in combination with the¢ 6502 halt line, control the switching¢ of the PIA bank number bits to A14/A15¢ and which bank of memory RAS goes to. ¢ Why people say freddy does the bank¢ switching is beyond me. An 800XL can¢ look like a 130XE with that 16-pin¢ chip installed (That's right NO¢ freddy) and an extra 8 RAM chips."¢¢ Beginners at using the 8-bit¢ Atari platform may wish to contact¢ Bill Kendrick,¢ URL:mailto:kendrick@sonoma.edu, for¢ his Newbie/Emulator FAQ.¢¢ The following is taken from Bill's¢ Newbie/Emulator FAQ.¢ Graphics:¢ The Atari has maximum resolution of¢ 320 x 192 (standard, non-overscanned¢ screen) x 2 colors.¢ 160 x 192 x 4, 160 x 192 x 2, 160 x¢ 96 x 4, ¢ 160 x 96 x 2, 80 x 48 x 4, 80 x 48¢ x¢ 2, 40 x 48 x 4 graphics are also¢ supported.¢ 40 x 24 x 256-character (128 normal,¢ 128 inverse, character set¢ indirection available) text mode is¢ standard (2 colors).¢ 40 x 24 x 128-multi-colored-¢ character (4 colors per character¢ allowed, the other 128 characters have¢ 4th changed into a color 5) and¢ 40 x 12 x 128-multi-colored-¢ character screen modes are available.¢ GTIA graphics support 80 x 192 x 16¢ shade-only, 80 x 192 x 16 hue-only,¢ and 80 x 192 x 9 color screen modes.¢ Graphics Modes Summarized:¢ Mode Horiz.xVert.xColorstext/graphics¢ 0¢ 40 x 24 x 2 text¢ 1 20 x 24 x 5 text¢ 2 20 x 12 x 5 text¢ 3 40 x 24 x 4 graphics¢ 4 80 x 48 x 2 graphics¢ 5 80 x 48 x 4 graphics¢ 6 160 x 96 x 2 graphics¢ 7 160 x 96 x 4 graphics¢ 8 320 x 192 x 2 graphics¢ 9 80 x 192 x 16 luminence-only¢ graphics¢ 10 80 x 192 x 9 graphics¢ 11 80 x 192 x 16 hue-only¢ graphics¢ 12 40 x 24 x 4-colored text¢ 13 40 x 12 x 4-colored text¢ 14 160 x 192 x 2 graphics¢ 15 160 x 192 x 4 graphics¢ Normal (bordered), narrow¢ (underscanned), and wide (overscanned)¢ screen modes are available.¢ Screen modes can be mixed (by lines)¢ down the screen using the Display List¢ (a program which is executed by the¢ ANTIC graphics chip every screen¢ refresh (60 times per second on real¢ NTSC Ataris).¢ Fine scrolling (both vertical and¢ horizontal) can be enabled on any line¢ on the screen.¢ All other screen attributes (color,¢ player/missile horizontal position,¢ screen width, player/missile/playfield¢ priority, etc.) can be ajusted at any¢ point down the screen via a "Display¢ List Interrupt."¢ Four 8-bit wide, 128 or 256 byte¢ high single color players, and four 2-¢ bit wide, 128 or 256 byte high single¢ color missiles are available.¢ A mode to combine the 4 missiles¢ into a 5th 8-bit wide player is also¢ available, as is a mode to XOR colors¢ or blacken out colors when players¢ overlap (good for making three colors¢ out of two players!) Players and¢ missiles have adjustable priority and¢ collision detection.¢ Sound:¢ Four voices of 8-bit pitch-¢ resolution, 4-bit volume-resolution,¢ 8-distortion sound can be produced. 2¢ voices (1 and 2, and/or 3 and 4) can¢ be combined to make 16-bit pitch-¢ resolution. Also 4-bit volume-only¢ modes can be enabled for digitally¢ sampled sound replay.¢ A fifth "voice" is produced by the¢ internal speaker on Atari 400/800's¢ (for keyclick and buzzer) and in the¢ XL's and XE's this was (fortunately!)¢ rerouted through the normal audio¢ output, and the keyclick can be¢ disabled.¢ ¢ (Ed. Go on the INTERNET to learn¢ more!¢ -- end --¢
