This FAQ exists to describe the various hardware modifications available to the Atari 8-bit user. It does not teach you how to do them. It definitely doesn't take any responsibility for the results if you do try them. But it will try to give you some information about where to find more information, which upgrades (or "hacks") are best, and who to consult if things go wrong. For addresses and phone numbers of any of the companies listed, consult the Vendors and Developers List, posted to comp.sys.atari.8-bit at or about the 15th of each month.
It also exists to describe the many wild, Woolley and wonderful products that have been produced for the Atari 8-bit. Many are unique, some may be apocryphal. Mainstream items like printers, modems, disk drives and cassette decks are all excluded, unless I feel otherwise. Temperature gauges, combination printer buffer/RAMdisks that run through the joystick port, and other such are fair game.
If you're looking for a list of Atari hardware (real or vapour-ware)
or for a list of Atari compatible disk drives, check out the comp.sys.atari.8bit
FAQ, posted every two months, and stored at the
University of Michigan archive .
This FAQ owes a debt of gratitude to Michael Current, Bill Kendrick, Glenn Saunders, Alan Sharkis, William Moeller, Ryan Goolevitch and Ben Corr for their contributions. Bob Woolley and Bob Puff (CSS) also deserve mention, since they are responsible for so many of the items listed here. All errors, omissions, blatant mistakes and attitude problems are mine. If you notice any, tell me!
Many plans for upgrades and add-ons are archived at the
BRiTiSH Underground Atari 8bit Web page.
|Key to abbreviations|
|ANL - Analog Magazine|
|AC - Atari Classics Magazine|
|ANT - Antic Magazine|
|AIM - Atari Interface Magazine|
The 6502 microprocessor at the heart of every Atari 8-bit has a sixteen
bit wide address bus. What this means is that it can access up to 2^16
memory locations. That's 65536 bytes. Some people, wanting more memory,
came up with a variety of techniques to use more memory. Most were built
around the idea of bank switching. Bank switching means that you swap chunks
of memory around so that the CPU can see them when necessary. Most schemes
use 16k banks, though 4k and 32k have also been tried.
The original Atari 400 had either 8k or 16k. Atari produced a board
with 48k. Mosaic produced a 32k board, as well as a 64k board with 48k
RAM plus 4 4k RAM banks. (ANL 13, IFC)
The Atari 800 came with three memory slots. Each slot could contain Atari 8k or 16k RAM boards. Mosaic produced 32k and 64k boards. Three 64k boards could be combined for 192k.
Axlon produced the 128k RAMdisk board. It banks 16k, using $CFFF as a control register. Banked memory appears from $4000 to $7FFF.
David Byrd created the "800 PLUS 288K UPGRADE" which rewired existing 16k RAM boards, but required additional work to become fully Axlon compatible. A nasty sort of flame war erupted between David Byrd and Jay Torres of the Windhover Project over who invented the upgrade.
Magna systems produced 256k, 512k and 1M
boards which followed the Axlon standard. (ANL 65, 68)
As shipped, the Atari 600xl came with 16k RAM. Atari released the 1064 memory module which expanded the 600xl to 64k. MPP, now Supra, produced the Microram 64k Memory Board (ANL 19, 28)
RC Systems produced three expansion modules for the 600xl, raising memory to 32k, 48k or 64k (ANL 26, 12)
Richard Gore produced the Yorky, a 256k board which plugs in to the PBI. It provides full compatibility with 130xe type banking. It is for use on 600xls upgraded internally to 64k, or on 800xls. (AC 3/2, 10)
The 600xl can be internally upgraded to 64k by replacing the two RAM
chips, and adding selects for the two address lines.
The Atari 800xl came with 64k RAM internal. To access RAM hidden under the OS ROMs, the PIA chip was used (PORTB, used for STICK(2) and (3) on the original 800). Claus Bucholtz published plans for a 256k upgrade which banked 32k at a time using PORTB for control in Byte magazine. (Byte Sept 85)
ICD released the RAMBO upgrade, providing 256k in 16k banks, using PORTB. Newell came out with the 256k XL, which would work on a 1200xl or 800xl, providing 256k total memory, . The two upgrades used different sequences to access their banks. (ANL 44, 115)
Charles Bucholtz updated his upgrade to use 16k banks after the release of the 130xe. Most of the 800xl upgrades can be made compatible with Antic banking. The only possible problem would be when Antic and the CPU are supposed to be using different memory banks.
The Yorky will also provide 256k on an 800xl (see the entry under 600xl).
Newell released 1Meg and 4Meg upgrades for the 800xl. These banked 16k as well, and required disabling internal BASIC to properly access the memory.
Fine Tooned Engineering, having bought the rights to ICD and Newell's products, is bringing out a third method in the Mars 8. Though not yet released, it will use SIMMs for 256k, 1Meg or 4Meg RAM.
The 800xl is arguably the most popular Atari 8-bit for upgrades, since
most 800xls have socketed chips.
The 130xe was the first "official" method of banking memory. It too used PORTB, but with an added twist: ANTIC and the CPU could access different banks. This provided headaches for some owners of "older" 800xl upgrades, but few programs took advantage of this feature (SpartaDos Wedge and VideoBlitz demo only). Upgrades for the 130xe include replacing one set of 64k chips with 256k chips, raising the RAM to 320k. Adding another 256k for 576k total has also been done. These were designed by Scott Peterson, as was a 1088k upgrade.
The most common video upgrades are the SuperVideo series, described in AC 2/6. Plans were provided for the 600xl, 800xl, 1200xl and 130xe. The SuperVideo upgrade provides the forgotten chroma signal on the monitor port. It corrects a number of errors in the parts in the Atari video circuit, resulting in a clearer image, particularly on monitors.
Providing TTL output was also covered in AC 2/6. Bob Woolley provided
plans for the circuit, as well as instructions for getting TTL output from
an XEP80. Be warned that the output is not in the standard Atari colours;
on a CGA type screen, the sixteen possible shades are translated into eight
Since the 400/800 were released in 1979, people have been clamouring for better text displays than the default 40x24. Two products were released for the 800: The Austin-Franklin 80 column board and the Bit 3 80 column board were both for use in the Atari 800. They replaced the third memory module. The Austin-Franklin board came with a "Right Cartridge" which provided the drivers. Removing the cartridge disabled the board. Some software would not run with an 80-column board installed.
Ace 80/80xl was a cartridge released which provided 80 columns by using bitmapped graphics on an 80 column screen. A similar technique was used in the Newell Omniview, an add-on for their Omnimon.
Atari's entry into the 80 column field was the much maligned XEP80. For maximum compatibility, the XEP80 attaches to the computer via a joystick port. It includes three character sets, 8k internally, and a parallel printer port. The software provided by Atari supports a 320x200 graphics mode. This mode only supports direct bit images. Hacks have been released which hook the XEP80 on via the parallel bus.
Recent terminal programs have added two other display techniques. ICE-T uses a graphics 8 screen and fine scrolling for its display. FlickerTerm uses two graphics 0 screens a half-character apart, each displayed during alternate vertical blanks.
In a series of articles in the SLCC newsletter, Bob Woolley gave hardware
plans for installing an 80-column TTL output inside an XL.
With the decline of Atari in North America, more and more quality software
was migrating across the Atlantic which was all but unusable. Why? European
Ataris are built for the PAL broadcast standard; North American Ataris
use NTSC. Not knowing it was impossible, Nir Dary upgraded an NTSC Atari
to run PAL software properly. Swap out the NTSC Antic chip for a PAL Antic,
do a minor modification to the OS, and voila! Your Atari is ready to join
the EU. (Better stop before the abbreviation police arrive!)
In October and November of 1991, Michael St Pierre published articles in the SLCC Journal describing plans for a monochrome Genlock. A genlock is a system to synchronize live video with a computer image. Graphics can be overlaid, faded in or out, or used for titling.
In 1994, Michael announced Prism Studio, a full colour genlock. It is
sold by Mytek.
Computer Eyes was a video capture system which plugged into two joystick
ports. It could render images in a variety of modes. It required a composite
video source. (ANL 35, 53)
Take a cartridge, add a fibre-optic cable, and hook it onto a printer,
and you've got Easy-Scan, an image scanner for the Atari 8-bit. Innovative
Concepts produced this item. (ANT 7/6, 43)
The original 400/800 had a 10k ROM OS. There was nothing in memory from $C000-CFFF. The later xl/xe models all had 16k OSes. As an added bonus, the xl/xe OS was in a 28 pin ROM that was pin compatible with a 27128 EPROM. What does this mean to the layman? With a little knowledge of 6502 assembly and an EPROM burner, you can write your own operating system (or at least change Atari's).
|A Summary of Atari Operating Systems|
UltraSpeed + OS: from CSS. Supports high speed disk communication. Drives 1 through 9. Any RAM upgrade. Includes three modes: standard XL/XE OS; 400/800 OS; UltraSpeed+ OS. For XL/XE systems.
Omnimon: from Newell. M/l monitor for 400/800. Installs into $C000 page of memory, otherwise unused.
RAMROD OS: from Newell. Replacement for 400/800. Includes accelerated floating point math package.
RAMROD XL: from Newell. OS speed-up routines, fast math, and Omnimon. Includes option for second OS.
Omniview: from Newell. Adds 80 column display, using Graphics 8 3-bit wide characters. Add-on for RAMROD boards, 400/800 and xl/xe versions.
XL Boss: from Allen Macroware. OS replacement for XL model computers. Includes m/l monitor. 400/800 OS compatible.
TurBoss: available from KP and Best. Fast math and fast screen routines. For XL/XE computers.
Turbo 816: Chuck Steinman at Dataque released a modified OS that used the 16 bit capability of the 65816 CPU upgrade he sold. For XL/XE computers.
DP OS Version 4: my own effort (don't ask about versions 1 through 3!). Fast floating point math, fast screen display, graphics 0 screen dump, fast keyboard repeat. For XL/XE computers.
SmartOS: This is a hardware upgrade that installs a battery-backed RAM chip into your XL/XE. This lets you fool around with changing the OS and not have to burn new EPROMs constantly. Presented in AC 4/3.
Warp+ OS: From Steven Tucker of APE fame. High speed I/O, 4 OS
versions. Plug in replacement for XL/XE computers. Full details at the
Covox sold the Voice Master and Voice Master junior. These would capture
and record speech. Bundled software attempted recognition of commands,
with limited success. (ANL 47, 44)
The Parrot was a sound digitizer sold by Alpha Systems. Resembling a
paddle, the device had phono jack for input. Antic provided plans for a
similar project, called the Antic Sampling Processor. (ANT 8/8, 11)
Among the more esoteric products ever released was the SoundMouse, which
interpreted sound to provide a reading on a paddle register. It did not
act as a digitizer, like the Voice Master and Parrot did. Bundled software
made the lava lamp look mainstream in its appeal. No commercial applications
taking advantage of this unique device were released.
Chuck Steinman of DataQue created this set of plans for building stereo
sound by installing a second Pokey chip (Pokey and Gumby, get it?). Once
installed, the second channel has all its addresses 16 bytes higher in
memory ($D210 - $D21F). A small number of demos have been released in stereo.
Lee Brilliant, ANALOG's resident hardware guru, came up with this system
for stereo sound, running it off the clock line on the SIO bus. As with
Gumby, it requires customized software to use. (ANL ???)
MIDI stands for Musical Instrument Digital Interface. It is a system
for computers to record, replay and control musical instruments. MIDIMATE,
when combined with MidiTrack software, permits an Atari 8-bit to take control.
Why buy an ST? (ANL 33:26)
This is a set of plans to make your own MIDI interface. Limited software
There was also a midi interface made by Wizztronics, called the MidiMax.
Unlike the MidiMate, it had not jacks for external sync, but it did have
an additional SIO port so it could be chained. It contained the same optoisolators
generally used in midi keyboards, and the case was riveted steel -- real
rugged. It came with Lee Actor's MMS software, some sample songs, a program
to convert AMS to MMS files, and a couple of six foot midi cables. Gary
Levenberg wrote the manual for the software. In addition, Wizztronics sold
a dozen or so double-sided disks of MMS songs that had been converted from
Atari users were notorious for their software piracy. The Happy Drive
(originally for the 810, later for the 1050) contributed to that reputation.
It was a modified 810, which could duplicate copy protected software. Thus
began a war between crackers and software houses. It also included a full
track buffer, which sped up operations and reduced the painful grinding
sound of the 810 at work. The 1050 version also made the 1050 into a true
double-density drive; version 7.0 would let the modified 1050 read and
write 180k MS-DOS disks.
The Atari 1050 drive was brain-damaged from the very beginning. Rather
than add a few dollars worth of parts to make a true double-density drive,
Atari invented their own format, called "dual-density", which stored 130k
on a disk. ICD produced the US Doubler, a hardware add-on that gave the
1050 true double-density. As an added bonus, it also included UltraSpeed,
which made "the normal beep-beep of Pokey sound like staccato machine gun
fire" according to one review. These drives, in order to use warp-speed,
had to have disks formatted in a special "Ultra-speed" sector skew. Unlike
the Happy which would buffer the whole track and warp it to the computer,
the USDoubler had limited ram and relied on the sector to be accessible
right when it needs to be read. Using a ultraskew disk in non-US mode was
REALLY SLOW :) A variant was produced which added 4 to the drive number,
permitting drives to be addressed as D5:-D8:.
This was CSS's entry into the 1050 DD sweepstakes. It included a high-end
crackers' toolbox, letting you edit sectors, create phantom sectors and
other fun stuff.
Eventually, software companies came up with a new copy-protection technique:
use 34 sector tracks and repeating sector numbers, so you get a "different"
sector #7 depending on where the disk is when you ask for it. CSS to the
cracker's rescue again! The Bit-Writer reads in tracks from the disk and
stores the bit pattern. This can then be re-written. Ironically, the software
disk that came with this upgrade to the Super Archiver was created on a
non-Atari machine, so users couldn't copy it.
Atari's last disk drive for the 8-bit wasn't quite perfect. This replacement
OS ROM from CSS fixed a number of bugs (can't switch back and forth between
SD and DD properly), and sped up the drive. A warning on upgrading the
XF551: The main PC board is lousy. It's REALLY easy to break traces - even
unplugging SIO cables can do it. BE CAREFUL!
CSS introduced these for the XF551. You could either replace the 360k
mechanism with a 720k one, or add a 720k to the 360k. Software included
let you read and write IBM disks.
Once again, someone couldn't leave well enough alone, ripped apart Atari
hardware, got bored with merely improving the OS ROM, and swapped out the
360k 5 1/4" mechanism for a 720k 3 1/2" one. This was sold by an outfit
called Innovative Concepts.
From Klaus Peters in Germany, this system provides a solid-state alternative
to floppy and hard disks. Using up to 8 27512 EPROMs, this setup provides
high-speed PBI access to commonly used software
Amdek released a new standard for disks: a rigid 3" plastic disk that
could store a whopping 360k (but you'd have to flip the disk for that).
It never caught on.
ICD manufactured this wonderboard in 1987. Connected to the PBI or ECI,
it provided either 256k or 1Meg of RAM, an RS232 port, a parallel printer
port and a SCSI hard drive port. The RAM can be configured as a RAMdisk
or printer buffer, or via software as a hard disk cache. To connect it
to a 130XE ECI required a special adapter that would convert the 130xe's
cartridge/ECI to an 800XL compatible PBI. The little board had two cartridge
slots (the rear of the two works for some cartrige types only, like Rtime
8) This looked better than having a tower of stackable cartriges coming
out of your 800XL! (Spartados X, Rtime8, and Action all plugged on top
of each other is rather obtrusive on an 800XL :)
Announced, sold but never delivered by Fine Tooned Engineering, this
PBI/ECI board will provide an interface and power supply for an IDE hard
disk. It may also include extended memory support for CPU upgraded computers,
as well as a parallel port. It was demonstrated at the TAF show in 1995.
CSS manufactures the Black Box, a PBI/ECI device that offers an optional
64k printer buffer. Its main attractions are its m/l monitor, 19200 baud
RS232 port, parallel port, and hard disk interface. The parallel and serial
ports do not use standard DB9 or DB25 connectors; custom cables are required.
This is an add-on to the Black Box, also from CSS. It permits standard
floppy drives, 360k, 720k, 1.2M and 1.44M, to be attached to the Black
Box. Since they are connected to the PBI, these drives operate extremely
quickly. Software included lets you read and write to MS-DOS format disks.
Supra released one of the first hard drives for the 800xl. It hooked
up via the PBI. KP bought the rights to the interface from Supra.
The earliest hard disk interface, the Corvus system hooked up to a 400/800
via joystick ports 3 and 4. A custom DOS would be booted from a floppy
disk to permit the computer to access the hard disk, which was divided
into 720 sector partitions.
New from Poland, this promises to let your XL/XE take control of new
IDE hard disks. Its design will permit future systems to break the 16 megabyte
boundary.Email for more info.
Some guys are constantly hacking hardware. And then there's Bob. Memory
upgrades? PBIs for 1200xls? 80 column devices? Battery-backed RAM operating
system? Somewhere, after all those, he found the time to interface the
xl/xe parallel bus with an IDE hard drive. Plans to be published in the
next Atari Classics magazine.
And now there is a new IDE-Interface available from germany. ~DM 120,
+ shipping. Works fine with Mitsumi CD-ROMs. Get in contact with the developers
SWP Computer Products made this original wonder-widget: Serial and parallel
ports, standard floppy interface, optional hard disk interface and even
CPM and MS-DOS add-ons.
A long time ago, in a galaxy far, far away, was a mystic operating system
known as CPM. A company named USS Enterprises produced the Critical Connection,
a device to permit a CPM computer to emulate disk drives for the Atari.
It was a cable, plus software for the CPM end of the system. The CPM system
could also act as a printer buffer, and the CPM keyboard could be used
in the place of the Atari keyboard. (ANL 39,103)
With the demise of CPM and the rise of the IMI cartel (IBM-Microsoft-Intel)
a new system similar to the Critical Connection arose. Nick Kennedy developed
the SIO2PC hardware and software, which permits any PC with a serial port
to act as up to four disk drives for an Atari. It can also act as a printer
Steven J. Tucker took SIO2PC one better and wrote new software. The
Atari Peripheral Emulator (APE for short) lets your PC act as high-speed
drives. It lets you print to your PC printer. And it lets you use your
PC modem on the 8-bit. It also permits, with a special cable, the creation
of backups of copy-protected disks.
In ANL 59,60 and 62, Dr. Lee S. Brilliant provided plans and software to turn a surplus Atari into a printer buffer for another Atari. He called it "The Atari Zucchini".
The Printer Buffer Routine (PBR) and Disk Emulator Routine (DER) came
from B.L. Enterprises. They were cartridges and cables which worked in
a similar fashion to the Zucchini. The PBR provided a buffer, while the
DER emulated a disk drive on the remote computer. Stock XLs gave 403 free
sectors; a 130xe would give 914. (ANL 65, 67)
With the use of PORTB for RAM banking, hackers were looking for more
parallel outputs. This plan, for adding one more PIA chip, includes notes
for adding two more. It was intended as a means to control large RAM upgrades.
(AIM 3/2, 16)
This radio station, when automating 6 broadcast hours daily, created
a hardware and software package built around a 130xe for control. Control
was via joystick ports and tone decoders. (ANT 8/7, 30)
This provided 8 or 16 channels and 2 or 4 sensors. It would monitor
the temperature, with options to log results to disk or printer, or to
sound an alarm if the temperature strayed out of set boundaries. The software
was described as "cumbersome". (ANL 48, 35)
During one of their periodic restructurings, Atari decided to sell their
computers as educational. Thus, the Atari Lab series was produced. The
two kits released provided experimenters with tools to measure light and
temperature, hooked in by the joystick ports. Of course, the next restructuring
left this an orphan product.
Released by DataQue, this provided a replacement OS as well as a replacement
for the 6502 CPU. A 65816 was substituted, providing new opcodes and a
24 bit address space (16Megs vs 64k with the 6502).
Released by Fine Tooned Engineering, this provides a 65816 CPU to replace
the 6502. Documentation and software were supposed to follow; I bought
#2 or #3 and am still waiting...
Notice one name popping up again and again? In AC 3/3, Bob began explaining
how to add a 14 mHz 65816 to your xl. That's right, parallel processing.
Complete plans were never published.
Supra provided the Atari community with its first networking product.
MicroNet provides nine SIO connectors. Eight are for computers. The ninth
goes to whatever peripherals are to be connected. The system served to
isolate the computers electrically. It did no software checking, meaning
that two or more users attempting to print or save at the same time could
trash each others output. (ANL 51, 76)
CSS provided a better way to network. The Multiplexer system requires
one host system which has all the disk drives and printers for the network.
The slaves are connected via the cartridge port to the host, and all their
disk and printer i/o is rerouted to the host. All the systems involved
require their OS replaced with a special multiplexer OS. The only thing
not shared by the network is the R: device, allowing the system to be used
for running a multi-line BBS with BBS Express! Professional BBS software
from K-Products, which is still actively supported. This was possible with
a special version of 4.0, and is built into 5.0.
The most recent innovation in networking the 8-bit Atari, GameLink II
permits up to 8 machines to share information for interactive games. Currently,
only the Maze of Agdagon supports this system. DataQue sells cables and
Released to on-line services and possibly to the Umich archive as well,
this set of programs was designed to interface computers by the joystick
port, using 3 bi-directional data lines and two control lines.
Even the most dedicated of Atari enthusiasts hates the xe keyboard,
with its mushy feel. Michael St Pierre created an interface for a PC keyboard.
Hook it in to your xl/xe, and plug in your PC keyboard. It includes programmable
macro keys and a number of other features. Be warned that the PC keyboard
isn't mapped the same as the Atari; for example, on the Atari SHIFT-2 gives
a ", while on the PC it gives a @. Available from Dataque.
This keyboard was a full stroke replacement for the Atari 400 membrane
keyboard, but they were very low keys....the touch was OK, but not excellent.
There were better keyboard replacements for the 400, but NONE of them fit
as well, or looked as if they were part of the orginal Atari 400.
The XE computers have arguably the worst keyboards ever made. To firm
up the squishy keys, Best Electronics sells this set of silicone switches.
It only works on one of the two xe keyboard models, though.
Huge RAM upgrades are great, but when your system crashes you can say
goodbye to all the info in your RAMdisk. Bob Woolley made this mod to add
a hard reset, by fooling the system into thinking that a cart had been
pulled out of the system. Your system reboots, but your RAMdisk contents
This is a clock cartridge for any Atari from Fine Tooned Engineering.
It includes a pass-through connector so that any other cartridge can be
plugged in as well. Though primarily intended for SpartaDos, software for
other DOSes is included.
Announced 'way back in Atari Classics 1/1, this product was intended
as a replacement for the R-Time 8 from Best Electronics. Software difficulties
have kept it from being released.
This was under development from Fine Tooned Engineering. For 800xls
only. Memory expansion of 256k, 1M or 4M using 30 pin SIMMs. Install internally
Action, Basic XL/XE, MAC/65, SpartaDos X, R-Time 8. Shown at the TAF show
in 1995, it was never commercially released.
This device hooks into the SIO line, and provides 4 9-pin RS232 ports
and a 15-pin parallel port. The RS232 ports are NOT IBM PC standard. The
MIO and PR Connection use the same pinout.
This device plugs into the SIO line, and provides 2 9-pin RS232 ports
and a 15-pin parallel port. It is powered by the SIO line. The Atari 1200xl
requires an internal modification to work with this device, or with the
Atari XM301 300 baud modem.
With 850s and P:R: Connections becoming increasingly rare, Kenneth Siders
released plans to build a high-speed serial interface using only 2 ICs.
Ever look in the back of an Apple II or an IBM PC, and envy the expansion cards? Atari was planning to release a similar expansion box. The full specs were written up, and prototypes were sent out to hardware developers. As usual, Atari took this great idea, buried it, and forgot about it. Add on cards included CPM and 64k RAM. These are EXTREMELY rare; I've only ever seen two for sale. Definitely collectors pieces.
The joystick port is a parallel port. The SIO port is a serial port.
So where would you hook up a serial modem? MPP (now Supra) plugged a 300
baud modem into the joystick port. Running at 300 baud, with software that
couldn't d/l files longer than 32k (an Xmodem bug), this is what got me
started in the on-line world, and what got Supra started in the modem business.
Wonder if I could trade in my old 300AT for a new 33.6k?
Manufactured by the ALIEN Group, this speech synthesizer even made it
into TIME Magazine in their "Machine of the Year" issue in 1982. Plugging
into the SIO line, this device would produce speech of the traditional
Protronics of California announced this 128k RAMdisk/printer buffer
which interfaced via the joystick ports, offering it as a replacement for
the 850. A 512k upgrade was promised. (ANT 2/8, 106)
Newell Industries announced this 850 replacement in 1983. It offered
two serial and one parallel port, along with an expandable 8k printer buffer.
(ANT 2/8, 106)
This bar-code scanner was from the Databar Corp. The intent was to permit
the speedy entry of computer programs which would be encoded in magazines.
(ANT 2/8, 107)
Hackers love the 1200xl for two reasons: because of all the space available
within the case, and because of the great keyboard. Bob Woolley came up
with this set of plans for adding a parallel bus interface to the 1200xl.
ANALOG magazine provided this unique information on interfacing an 8-bit to a Radio Shack Armatron remote controlled arm. Positioning was determined using the paddle/potentiometers, and control was via the PIA (joystick pins).