On May 17, 2007, at 11:51 PM, Chuck Guzis wrote:
The switches are exactly what they say they are.
Switch 1: On: A19 = 0; Off: A19 = 1
Switch 2: On: A18 = 0; Off: A18 = 1
Switch 3: On: A17 = 0; Off: A17 = 1
Switch 4: On: A16 = 0; Off: A16 = 1
Switch 5: On: 64KB installed on board
Switch 6: On: 128KB installed on board
Switch 7: On: 192KB installed on board
Switch 8: On: 256KB installed on board
Ok, I wasn't sure whether switches 5-8 were for the memory on the
board, or the memory on the planar, and that every one of the boards
I already have are set up with bogus switch configurations (like, on
off on on on off on off, and off on on on on on off off). No wonder I
was confused.
Okay, so let's assume that you've got the
original 5150 with 64KB of
planar memory installed. Further, let's suppose you've populated the
memory expansion card with 4 64K memory modules for a total of 256KB.
You'd set the switches as follows:
Switch 1 = On, Switch 2 = On, Switch 3 = On, Switch 4 = Off
Switch 5 = Off, Switch 6 = Off, Switch 7 = Off, Switch 8 = On
Then it follows that for 64 KB on the planar and 192 KB on the card,
it'd go on on on off off off on off. Right? And then I set the
switches on the planar as if it were a 256 KB 5150 (SW1 x x off off x
x x x / SW2 on off off on on off off off).
This adapter requires the goofy 32-pin IBM 3-supply
64K modules.
Neither the adapter nor the modules are very common in my experience.
I've got four or five of them with varying degrees of memory
installed, so there's another datapoint for you.
Thanks, Chuck. For now, I discovered I had one TECMAR All-In-One card
with 192 KB which was already set up correctly in another 64 KB 5150
(which has some problems with its floppy disk drives) so I borrowed
the card. I'll give it a shot with your settings and see what
happens. Some of my DRAM chips may be bad.
This is all in an effort to IPL my 5364 S/36 PC for the first time,
FWIW.
ok
bear