Radek Štìrba (Raster) & Robert Petružela (Bob!k)

This Atari XE/XL cartridge made by raster & bob!k / c.p.u. makes possible to load, keep and run most of existing Atari XE/XL cartridge games or other special software. It has memory 128 KB SRAM powered by Atari computer or by one small 3V battery when the computer is turned off.

General description - version "G1.04 FIX3+"RAMcart

Bank switchingRAMcart bank-switching. Click for big picture.

This cartridge uses bank switching with 16x8KB banks in two memory locations. Lower area $8000-$9fff can map any from 16 banks (0-15) by storing bank number to $d500 ($d5xx), upper area $a000-$bfff has constantly mapped last bank (15). This system is fully compatible with so-called XEGS cartridge bank-switching style, so all the XEGS cartridge games/software is working very well.
If cartridge is in ”SXEGS mode” (switchable XEGS), then there is possible to enable/disable cart via software by bit 7 of stored bank number value (bit 7 is unset => cart is enabled; bit 7 is set => cart is disabled).

Controlling software

For loading of any cartridge ROM dump file, you can use program ”XEGS RAMcart File Feeder” (RFF). It’s easy to use it – you have to specify device and filename, or only device with colon (or you can use *.*, *.ROM, etc.) and press Return for selection from directory listing.
Supported file types are raw cartridge dump files (ROM, BIN), also CAR format with head information (cartridge type) is possible to use.
RFF will recognize size of cartridge (from 8 to 128 KB) automatically and then fill the cartridge memory banks as it’s needed. If some problem occurs, it shows relevant message or it will ask for next action.
Note: We were shortly testing most of available Atari XE/XL cartridge game dump files (all ROM sizes: 8, 16, 32, 64, 128 KB) published on www.atarimania.com site and all of them was working perfectly.

Cartridge controls / indicatorsRAMcart

Sample cartridge game dump filesRAMcart

Note: Classic Atari XE/XL cartridge games are running directly from the cartridges, so RAMcart will be enabled all the time. But following games are cartridge versions of originally no-cartridge games, that is why they need to disable the RAMcart after the game initialisation. In ”SXEGS mode” RAMcart will be disabled automatically. If RAMcart isn’t in ”SXEGS mode”, you will be asked for disable the RAMcart manually (by pressing cart disable button). 
If you want to run game from the RAMcart again, you have to enable RAMcart manually (by pressing cart enable button) and then press the Atari reset key.

Special software

This is hastily patched version of DOS II+ by Stefan Dorndorf (freeware / PD software).
After execute SXEGSD2P.COM, DOS is stored into RAMcart memory and you can start it from the cartridge every time. It has default device D8: and this device uses SXEGS RAMcart memory as 120KB ramdisk (cart battery keeps his content when Atari computer is turned off). 

Other cartridge dump files

We recommend the site www.atarimania.com, where you can find a lot of cartridge dump files of classic old Atari games, as well as old great but lesser-known XEGS games, for example Rescue on Fractalus (1987, 64KB, with original game intro), Tower Toppler (1988, 64KB), Commando (1989, 128KB), etc.

Important notesRAMcart

Two versions of GAL firmware exists, so you can choose which behavior seems to be better for you and use one of them:

  1. If you will use firmware "sxegsramcartG104_GAL.jed" :
    Each time you turn on the Atari computer, the RAMcart is enabled by default and started automatically. If RAMcart memory is empty or it doesn’t contain any functional cartridge ROM image, system can crash immediately. In this case you have to disable RAMcart by pressing ”Disable&Reset” button and then press the Atari Reset key.
  2. If you will use firmware "sxegsramcartG104_GAL_defaultdisabled.jed" :
    Each time you turn on the Atari computer, the RAMcart is disabled by default. If you want to activate RAMcart, you have to enable RAMcart by pressing ”Enable” button and then press the Atari Reset key.

Every time when RAMcart is enabled and "write" switch is turned on, you have to avoid pressing the Atari Reset key and/or turning on Atari computer, because OS ROM initial routines will clear the main part of RAMcart memory in the other way!


The authors take no responsibility for any damages, which may take place during building and/or using of this hardware and/or software. 

Download complete production documentation

Additional PC software for S/XEGS RAMcart



Bob!k/c.p.u. presented his first wired XEGS RAMCART prototype
at Atariklub Prostìjov meeting.
Bob!k/c.p.u. and Raster/c.p.u.
We were discussing about ramcart scheme details and new ideas.
The first "final" prototype without switchable feature.
(There was faultiness in memory writing process sometime.)
The second version. GAL chip used for switchable feature,
component parts moved to the bottom PCB side.
There are some additional hotfixes on both sides of PCB.
Final S/XEGS RAMCART 128KB by C.P.U.,
version G1.04 fix3+.

Gratified owners & users of S/XEGS RAMcart

raster/c.p.u., bob!k/c.p.u., fandal, krupkaj/jaysoft, bohdan, -xi-/satantronic, alex, pepax, etc. ;-)

Vyrobil Radek Štìrba, © RASTER