Is possible to detect btw. GeoRAM/NeoRAM ?

  • Is possible to detect btw. GeoRAM/NeoRAM ?

    Hi!

    I found some tips on web how to programming GeoRAM.


    I have simple Q:

    Is possible to detect between GeoRAM and NeoRAM type?


    I'm not sure how to detect btw. REU and Geo/NeoRAM, but I found st. about registers of GeoRAM.

    Else one Q?

    Is correctly that BBGRAM = Baterry Backuped GeoRAM ?


    Many many thanks for every help.

    Miro
  • MIRKOSOFT schrieb:

    Is possible to detect between GeoRAM and NeoRAM type?


    Not easily. The register set is the same and consists of only two registers at $DFFE and $DFFF. In the original GeoRAM there are mirrors of the registers in the whole $DFxx page, while NeoRAM in its standard config uses only $DFC0-$DFFF. Of course, this can be changed to imitate the original behaviour by changing a set of jumpers, so this isn't a 100% sure method to detect a real NeoRAM. On the other hand, I only included these jumpers for compatibility tests and I don't know of a single person who changed them to the original GeoRAM setting ;)

    Also, NeoRAM decodes 2MB RAM by default, even if only 512kB is installed. This also can be configured to 512kB decoding if some software needs it. And it does not apply to models with 2MB of RAM.

    MIRKOSOFT schrieb:

    Is correctly that BBGRAM = Baterry Backuped GeoRAM ?


    Yes, it's another clone of GeoRAM with an external battery pack. The external pack is needed because DRAM is used which uses a lot of current for refreshing and has no real standby mode like SRAM as used on NeoRAM.
    Zuletzt repariert:
    21.2. Logitech M570 Microschalter ausgetauscht - geplante Obsoleszenz durch Billigtaster?
    19.11. Toshiba 3,5" Floppy defekter Elko durch Kerko getauscht auf Motorplatine
    27.11. 1541B Dauerlauf, Elko im Resetschaltkreis defekt, nicht der 7406 wie zuerst verdächtigt!