512K Ram; with hooks for 2 to 4MB.
The testbed for more RAM started with this hand-wired kludge.
It is a half-stick of 16mb x 32 bit PC memory.
Yes, it was cut into two pieces and re-wired to work here.
Backside of that PCB. Some Tektronix folks may recognize this board.
This shows the half-stick (72-pinner) upside down and wired in.
Here it is mounted into a Tandy CoCo3 and being tested.
NitrOS-9 (6309E) reported the 512K as useable.
This is the hand-drawn schematic to wire that half-stick of memory to the interface board.
My second $2 JLCpcb order came in on 5-29-2018 one day early.
It looks like this:
Mounted into a Tandy CoCo3 it reports 512K. It worked the first time. Only two pin labels were swapped. The 4 chips are 4mb x 4 bits. Address legs A9 and A10 are grounded for now and will be available when the DAT PCB is finished. The drams are hand-soldered. I did need to relieve the PCB around the RF can. The fun part was adding the 36 square pins. Testing revealed no bad drams. These drams were removed from 16mb 72-pin memory sticks.
IdeZilla
Comments Welcomed
It is a half-stick of 16mb x 32 bit PC memory.
Yes, it was cut into two pieces and re-wired to work here.
Backside of that PCB. Some Tektronix folks may recognize this board.
This shows the half-stick (72-pinner) upside down and wired in.
Here it is mounted into a Tandy CoCo3 and being tested.
NitrOS-9 (6309E) reported the 512K as useable.
This is the hand-drawn schematic to wire that half-stick of memory to the interface board.
My second $2 JLCpcb order came in on 5-29-2018 one day early.
It looks like this:
Mounted into a Tandy CoCo3 it reports 512K. It worked the first time. Only two pin labels were swapped. The 4 chips are 4mb x 4 bits. Address legs A9 and A10 are grounded for now and will be available when the DAT PCB is finished. The drams are hand-soldered. I did need to relieve the PCB around the RF can. The fun part was adding the 36 square pins. Testing revealed no bad drams. These drams were removed from 16mb 72-pin memory sticks.
IdeZilla
Comments Welcomed
Looks great!!!
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