Re: Mice and the IIgs

[spec@vax2.concordia.ca (Mitchell Spector)]

In article <3429C87C.7A6B@home.com>, slam@home.com writes...

>Mitchell Spector wrote:
>>
>> In article rkneusel@post.its.mcw.edu writes...
>>
>> >I was recently given an Apple IIgs (ROM 01, 512k RAM, color monitor) that
>> >"locks up" when I boot the System Utilities disk that came with it.
>> >Actually, two came with it.. version 3.1 and 5.x and neither work.
>>
>>     First off you should really consider expanding the memory of this 
>> system to at least 1.25 MB (just populate the memory board inside with 
>> 256Kx1 chips which can be found for literally pennies these days).
>
>You mean the Apple IIGS memory expansion card accepts 256Kx1 memory
>chips? That's interesting...

    Yes, though they must use a CAS before RAS refresh scheme (column
address selection is done before row address selection). As well they
should be at least 150 nanoseconds or faster. They're fairly common
to find populating old PC 8088, 8086 and 286 motherboards, which are
sold almost like scrap these days (when I visited a PC Expo back in
the spring, one vendor had a box overflowing with 286 motherboards at
a cost of $1/ea. Each had at least a megabyte worth of 256Kx1 chips).

>but are there any programs to test the real amount of ram?

    Assuming you haven't confused the IIgs by putting in the wrong type
of chips or setting jumpers incorrectly, you can verify how much memory
is installed by simply looking in the 'RAM Disk' selection from the built-
in Control Panel (press and hold down Apple-Control-Esc). Add 256K to
the 'Largest Selectable' size displayed and that is your total RAM.

>I can put two jumper blocks on my board and the computer thinks it has
>2mb, but when I take the blocks off I'm back to 1,256k...

    If you short both jumpers the card will think it is fully populated
to 1024K (all sockets filled). If the whole bottom row is empty, you
short ONLY the TOP jumper, for 512K. If there are no chips in any sockets
(minus the 256K soldered on the card as default) than you need to remove
BOTH jumpers.

>the standard 1mb on m/b and then an extra 256k on a iigs expansion card
>that is currently only 1/4 populated with soldered-on ram..

    See above, you need to _remove both_ jumpers (or better yet, just
offset them so they are only resting on one of the two pins. This is
the same as removing the jumpers, but they won't get lost).

    Sounds like you have a ROM 3, installing the bare card will bring
your memory up to 1.4 MB (if you populate the card, you can increase
that to 2.125 MB of memory, which I'd recommend you do).

>I think memory prices for special cards are kind of high so it would be
>nice to use 256Kx1...as long as there was a way to test! Thanks in advance.

    If you want to run a memory diagnostics check, there are a couple
of programs out there to do this. The most common is "MemoryTest.CL"
which is found on AppleWorks GS 1.1's third disk. The next option is
the Apple II Diagnostic disk which Apple dealers had, it should test
all the memory on the main logic board and anything it finds in the
expansion slot. I obtained the latter because I knew a friend who
was working at an authorized Apple dealer. I have no idea what the
status of either program is (though it would be nice to have them
legally reclasified as freeware).

Mitchell Spector
spec@vax2.concordia.ca