Power Cartridge

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Power Cartridge Screenshots
Power Cartridge Screenshots
Technical Info
ROM 16 kbyte
RAM 128 byte
Hardware features 1 Button Freeze
optional: ON/OFF Switch and 1 Button Reset can be added
Manual Power Cartridge V1.0 Manual Project64.txt

PDF: 42 pages - english
PDF: 42 pages - dutch
PDF: 43 pages - dutch and french
PDF: 42 pages - german
PDF: 42 pages - german and italian
PDF: 44 pages - swedish
JPG: english cheat sheet

JPG: german cheat sheet
Control Registers $DE00/$DE80 (somehow)
  IO1 area $DE00 - $DEFF provides ROM mirror of $9E00
  $DF00 - $DF7F has the Cart RAM accessible (possible mirror at $DF80)
Thanx to Markus B. and Draven for missing manuals!

Power Cartridge by K.C.S. (Kolff Computer Supplies BV, Holland) became available in Europe in the middle of 1986. Several companies distributed the Power Cartridge in various countries in the PAL domain but it seems the cartridge never was sold in the USA. In Europe however it was available for over 6 years without any change. The Power Cartridge came without version number but used the year instead. The sprites at startup of the first version state "1985" which was before actual commercial release. KCS as a company moved on to Amiga but did a second production run of the cartridge about 4 years later which came with a slightly different hardware design.

Power Cartridge from top

The ROM was edited for the 1989 edition but there were no code changes at all. The powerup sprites got changed as well as a copyright message at the end of them ROM.

The manual situation is somewhat interesting. The english translation of the "Nederlandse handleiding" is available as etext but no original english documentation was found as of yet (HELP!). Power Cartridge manuals we have seen were bundled as german and italian or as dutch and french where each language occupies half of the booklet. The back cover of the dutch&french booklet comes with an english cheat sheet while the german&italian version appears to go by a german cheat sheet. Apparently there is an english manual available which has the picture changed to show a cartridge with some flashes towards the C64. We are not sure wether it it may contain a spanish back cover though.

Power Cartridge Advert 10/1986
Power Cartridge Advert
Your Commodore 25, 10/1986
Power Cartridge Advert 12/1991
Power Cartridge Advert
Zzap!64 Issue 79, 12/1991

16kb of ROM provide a solid base for the most important BASIC toolkit commands and a proper fastloader. The 128 bytes of RAM seem a little lost but RAM is indeed necessary for proper freezing. Looking at the cartridge board there are two places especially marked which allow to add an ON/OFF switch and a reset button demonstrating that KCS knew what else people might have wanted.

The freezer is somewhat special. It appears to achieve better results than the ones from ISEPIC and Capture and due to its equal char packing algorithm the used disk space is considerably less than e.g. a Capture snapshot occupies. The Power Cartridge is required to restart a frozen program though since a special file format is used. There is no option to save the special loader required to run a back-up and what seems worst is that DLOAD as standard fastloader does not detect the frozen file but BLOAD needs to be executed.

The frozen program is relatively easy to detect. The three files saved to disk are of type USR and should get the name of the program last loaded with an extension each using a hash sign (#), a string sign ($) and a percent sign (%). The default for the snapshot is BACKUP which may leave you with:

80      "BACKUP#"      USR
6       "BACKUP$"      USR
80      "BACKUP%"      USR

Additionally to this freezing behaviour the freezer allows entering the monitor but the frozen program cannot be restarted nor are the register values of the frozen program taken to the monitor register display. The possibly most annoying feature has to be mentioned towards the end though: the monitor beeps on every error (next to the usual ? output). This not only slows down input times slightly but turns out to be a real annoyance after some time. On the other hand the monitor error messages are quite extensive and point towards the problem.

Power Cartridge ROM is definately packed with feature and the average programmer will not want to miss it but the cartridge sure could have used a few smaller improvements over time. During quite a few years it was always mentioned on tests with the big ones, Final Cartridge, Action Replay and Super Snapshot but was surely outfeatured by many due to its smaller hardware dimensions and back then outdated ROM.

There was no related software released so just the ROMs and CRTs are provided below. Fans of this cartridge should not miss The System Demo by System and the Power Cartridge Simulator by Dutch USA-Team.


  • 64'er Magazin May 1986 (german news article) interestingly had the first announcement we found for the Power Cartridge so far. There is no doubt about announcements on other magazines also during May '86 but maybe even earlier hints can be found somewhere?


The following is shamelessly ripped from kcs.c from the VICE emulator. Most of the text was written by Groepaz:

    - 16kb ROM, 128 bytes RAM

    - the second last page of the first 8k ROM bank is visible
    - bit 1 of the address sets EXROM and R/W sets GAME

    - 00-7f cartridge RAM (128 bytes), writable
    - 80-ff open area where the GAME/EXROM lines can be read (pull resistor hack)

    - the cartridge starts in 16k game mode

    the original software uses:

    bit $de00   -> ROMH off

    sta $de00
    sta $de02
    sta $de80   -> ROMH on (a000)

    bit $df80 at beginning of freezer NMI to find GAME/EXROM status

    ... and also code is running in deXX area

  ROM is selected if:                 OE = (!IO1 = 0) | !(!ROMH & !ROML)
  RAM is selected if:                 CS = PHI2 & (!A7) & (!IO2)
                                       (not A4, that's a mistake on the schematic)


  • Control register information (improve)


Power_Cartridge_KCS_binaries_rr.c64.org_2021-01.rar contains just the C64 binaries:

  • KCS Power_Cartridge 1985 v1 and v2 .bin and converted .crt
  • KCS Power_Cartridge 1989 version .bin and converted .crt

Power_Cartridge_KCS_all_rr.c64.org_2021-02.rar contains: