First look at: geoRAM


    geoRAM from Berkeley Softworks is a memory expansion peripheral for use
with GEOS 64 and 128.  It includes new boot disks for both, which are required
to use this unit, which is not compatible with the CBM 1764/1750 REU units.
This new GEOS release is designated GEOS 2.0r.



What's in the box?


    : Two "flippy" 5-1/4" disks, one primary, one backup.  Each has a GEOS
      64 2.0r boot disk on the front, and a GEOS 128 2.0r boot disk on the
      back.
    : GEOS 2.0r For Use With geoRAM User's Manual, 92 pages, saddle-bound.
    : Product registration card.
      and, of course,
    : geoRAM 512k memory expansion unit.  The unit itself is roughly 3-1/2"
      wide, 1-1/8" high, and 7-1/4" long, including the connector.  It will
      extend about 6" from the back of your computer, a bit more than a 1750.
      A number of electronic components are exposed near the connector, but
      these will all be concealed (and protected) when the unit is installed.


What's on the disks?

    geoRAM requires replacement of the GEOS kernal and Configure files.  The
supplied disks, after installation, are boot disks with these changed files.
The installation process is typical GEOS procedure, but it is especially
important to remember to key your new boot disks to your existing Applications
master disks, so that your existing copy-protected applications can be used
with your new boot disks.  Read the installation section of the User's Guide
carefully.  It contains the best set of GEOS installation instructions BSW has
ever supplied.


Required/recommended hardware/software:

    - Commodore 64 or 128, any model.
    - Compatible monitor.
    - One 5-1/4" drive (1541 or 1571).
    - Blank 5-1/4" floppies.
    - Supported GEOS input device.
    - GEOS 64, 1.2 or later,  or GEOS 128, any version.  Note that this package
      is unlike the GEOS 2.0 upgrade package in that it only replaces your
      boot disks.  It does not include new versions of the applications or desk
      accessories.  It is also unlike the old 1351/1764 GEOS upgrade disks in
      that it provides replacement boot disks, rather than overwriting existing
      ones.
  Additionally, the following is recommended:

    - Additional drives (1541, 1571, or 1581.)
    - GEOS supported printer.


Features:

    From a GEOS user's point of view, the geoRAM is almost identical to the CBM
1750 REU.  It provides 512k of RAM that can be used to emulate the 1541 or 1571
drives, to "shadow" a 1541 (a full-disk cache scheme, similar to that used on
high-price PCs and mainframes,) or to shadow the 1581 directory.  It does not
support the DMA option present with the true REU units, since that requires the
MMU chip present in those units, which is proprietary to Commodore.  This
results in some operations being slower.  This is most noticeable when
scrolling down a geoPaint document, even when geoPaint and the document are on
a RAM disk.
    Like the REU units, geoRAM provides room for fast reboot of GEOS from
BASIC, a home for the Superdebugger feature of geoProgrammer, and, perhaps most
important, permits a program resident on one type of disk to access data files
from a different type, since the "disk driver" portion of the desktop is
automatically, and invisbily, stored there.
    The special GEOS 2.0r boot disks are functionally equivalent to the
respective GEOS 2.0 disks.  No new functions are provided.  The only changes,
in fact, are to the GEOS KERNAL file, and to the CONFIGURE program.


Kudos:

    The User's Manual is attractively designed, and contains explicit, step-by-
step installation instructions for the replacement boot disks.
    geoRAM arrived by UPS Second Day Air.  This UPS option includes Saturday
delivery, which allowed the unit to arrive the weekend before Christmas, rather
than the Tuesday after.  Nice touch!


Concerns:

    Unlike the 1764 REU for 64, no special power supply is provided with the
geoRAM.  Attempting to use a true REU with a stock 64 power supply is an
invitation to disaster, since the additional power requirements of the REU
cannot be met.  According to the User's Manual, geoRAM "is designed using only
High Speed CMOS technology... An external power supply upgrade is unnecessary.
The total average current drain is about 80ma."
    In order to quell my personal doubts about the wisdom of using this unit
with a stock 64 power supply, I conducted a burn-in test, as follows:
    A C64, with standard power supply and 1670 attached (to provide some extra
load,) was left powered up for 24 hours.  Following successful completion of
this test, the computer was powered off, the geoRAM unit was attached, and the
test repeated for a further 48 hours.  There were no problems encountered.
While I'm still concerned about geoRAM pushing marginal power supplies "over
the edge," it appears that most users will have no trouble in this area.  With
it's robust stock power supply, the 128 is quite capable of driving a true REU,
and should have no problems at all with geoRAM.


Problems:

    With one exception, discussed below, no problems were encountered during
testing.  A wide variety of GEOS software performed correctly with geoRAM
installed.  In some cases, there was a noticeable, if small, loss of
performance compared to a 1750 REU installation, but this was expected.
    The one program that did present a problem was Joe Buckley's REU Zap II.
This program copies all files present on a RAM disk to a single Application
file, which can be used at a later date to recreate that RAM disk.  Thus, a
variety of RAM disks, tailored to specific applications, can be created
quickly.  When used with geoRAM, the results are unpredicatable.  It doesn't
crash, but some programs on the recreated RAM disk do crash.  I left a message
on CBMPRG forum letting Joe respond to this.  His reply follows:


#: 21893 S15/GEOS Programming
    31-Dec-89  13:23:14
Sb: #21892-geoRAM vs REU Zap
Fm: Joe Buckley/GEOS SL 71570,2600
To: Ed Flinn 76703,4032

Ed,
        Actually, I'm surprised it got that far.
        I use all of the GEOS REU variables and system calls to get access to
the REU (ramSize, FetchRam, StashRam).  In theory, if they emulated the REU
calls acurately enough, it should work.
        You've already said that the superDebugger runs in the new unit.
        The 'Clear REU' option is designed to 'hang up' due to its method of
clearing.  I assume you mean it acts differently from the way it does on an REU.        Generally...it should work, but without one to beat around, I have no
way to run tests.
                                                            Joe

    With this in mind, I now suspect that some other programs will turn out to
have compatibility problems with the unit.  My testing has not uncovered them.
This document will be updated with further information, when it becomes
available.


Quibbles:

    No program for testing the geoRAM is supplied.  While the lack of native-
mode and CP/M mode support is even more significant, it would be unfair to
blame BSW for these.  A GEOS application to test the integrity of the unit
should have been provided, though.



In conclusion:

    GEORAM is a desirable addition to a GEOS system for those users who are
unable to obtain a 1750 REU.  It provides the same storage, and only slightly
less speed.  It is not compatible with the REU units, and can only be used with
GEOS at this time.  It seems likely that only the most forward-looking
providers of commercial software will support this unit.  If Commodore should
decide to resume production of the 1750 at levels that make it generally
available, this will be assured, since few well-informed users would buy this
in preference to a 1750.  At present, though, it seems unlikely that CBM will
do so.
    With no CP/M or RAMDOS support available for the unit at this time, it is
poor competition for the 1750, but it has one outstanding advantage: it is
available.  My advice: if you can find a 1750, buy it.  If you can't find one,
and want the advantages it brings to GEOS, then buy the geoRAM.  If you're a
CBM or CP/M programming whiz, buy the geoRAM, and design the 64/128 and CP/M
utilities the rest of us are waiting for.




Ed Flinn, CBMART Sysop, 76703,4032
12/31/90
