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britlord
3rd April 2015, 00:51
Guys. I have a Mega Midget_Racer board with the ram expansion, and I'm stuck on setting it up. You see I got from Voyager_1701e, and he said that it has 2MB or ram (All the banks were filled though). Now I have installed 1Mx4 DRAMs (All 16 of them) so total ram is now 8MB. But reading the manual about setting up all the "W" jumpers on the board for 8MB of ram has me confused, and the speed of the ram is 60ns.. I would be gratefully appreciated if someone could figure it out for me. Here's a picture of the jumpers and the text too (Some jumpers have 4.7k resisters, and others 0 Ohms)...


Jumper JP1, located near the large, square controller chip on the daughter-board,
needs to be set according to the size of the DRAM chips being used. If 256kx4 DRAM
chips are used, then JP1 should be set to short (connect) pins 2 and 3 (labeled “256kX4 DRAM”).
If 1Mx4 DRAM chips are used, then JP1 should be set to short pins 1 and 2 (labeled “ 1MX4 DRAM’)

Jumper JP2, located next to JP1, must be set to short (connect) pins 2 and 3. Your
board may already be hardwired at the factory.

Jumper W1, labeled “SIZE”, is also set according to the size of the DRAM chips being
used.
If 1Mx4 DRAM chips are being used, a black shorting block should be placed over jumper W1. For 256kx4 DRAM chips,
W1 should be open..

Jumper W2, labeled “BANKS”, is set according to how many banks of DRAM are
installed. If both banks are fully populated with appropriate DRAM chips, a shorting
block should be placed on W2 . If only Bank 1 is populated, W2 should be open...

Jumpers W3, labeled “PAGE”, and W4, labeled “STATIC”, are set according to the type
of DRAM being used. If all DRAM chips installed are Page Mode DRAMs, a shorting block
should be placed on W3 . If all DRAM chips installed are Static Column Mode DRAMs, a
shorting block should be placed on W4 . For all other cases, or if you are not sure what
type of DRAM is installed, W3 and W4 should be open.

Jumpers W5 and W6, labeled “ACCESS TIME”, are set according to the speed, or
access time, of the DRAM being used. Use the table below to determine the settings for
jumpers W5 and W6. Use the access time of the slowest DRAM chip installed to ensure
proper operation (the slowest chip has the largest access time). DRAM chips with
access times greater than 100ns cannot be used with the CSA Mega-MemoryDRAM daughter-board


Access Time Jumper W5 Jumper W6
100ns open open
80ns open shorted
70ns shorted open
60ns shorted shorted

Tahoe
3rd April 2015, 06:57
You have the A2000 version of the RAM board which uses ZIP memory. The manual states that this version has no user selectable jumpers, but most likely the jumper configuration is pretty much identical to the DIP version.
In this case though I am afraid you will need a soldering iron to change jumpers!

britlord
3rd April 2015, 14:15
You have the A2000 version of the RAM board which uses ZIP memory. The manual states that this version has no user selectable jumpers, but most likely the jumper configuration is pretty much identical to the DIP version.
In this case though I am afraid you will need a soldering iron to change jumpers!

Ok. though the one that I did change was the JP1 (Short pins 1 and 2).. Thanks..