Gary C
Veteran Member
Just found something !
The North star 16K & 32K Dynamic RAM board instructions includes specific modifications to allow the Dazzler to work with it and the Z80. So I should be able to get it to work in a N*
Which is nice.
This is from the 16K board manual, the 32K instructions has something similar
Modifications
SPECIAL DMA APPLICATIONS
This section describes modifications for the RAM-16-A which may be necessary for use with such DMA devices as the Cromemco DAZZLERTM. These modifications are only needed if the RAM-16-A is being used with a Z80 or Z80A processor board. (To use the RAM-16-A with a special DMA device in an 8080-based system, it is necessary only to install a resistor as described in step D1 below.)
D1. If the DMA device is simulating an 8080 memory cycle, D07 must be true during PSYNC. If the device does not drive D07, a pull-up resistor (say, 1K) to Vcc will suffice. A logical place to add this resistor would be at the DMA controller.
D2. Install resistor R12 (220 ohm, red-red-brn) at location 5E and capacitor C10 (33pF dipped mica) at location 5E. This RC circuit acts as a delay for the CC-DBSL/ signal.
D3. Add an unused inverter to the circuit by connecting a jumper wire between the location labeled PHLDA (location 7E) to 2C pin 11 and another jumper wire from 2C pin 10 to 2D pin 12. Now cut the trace from 2C pin 12 to 2C pin 10.
D4. Add a second inverter to the circuit by connecting a jumper wire from the location labeled CC-DSBL/ (location 4E) to 7C Pins 4 and 5 and another jumper wire from 7C pin 6 to 7D pin
1. Also, cut the trace on the solder side of the PC board between 7D pin 1 and 7C pin 7. This allows memory cycles to start on the condition: PSYNC AND PHI 1 AND CC-DSBL/
D5. On the header at location 7D, be sure the jumper from pin 1 to pin 2 is installed, as it should be for Z80 operation.
The North star 16K & 32K Dynamic RAM board instructions includes specific modifications to allow the Dazzler to work with it and the Z80. So I should be able to get it to work in a N*
Which is nice.
This is from the 16K board manual, the 32K instructions has something similar
Modifications
SPECIAL DMA APPLICATIONS
This section describes modifications for the RAM-16-A which may be necessary for use with such DMA devices as the Cromemco DAZZLERTM. These modifications are only needed if the RAM-16-A is being used with a Z80 or Z80A processor board. (To use the RAM-16-A with a special DMA device in an 8080-based system, it is necessary only to install a resistor as described in step D1 below.)
D1. If the DMA device is simulating an 8080 memory cycle, D07 must be true during PSYNC. If the device does not drive D07, a pull-up resistor (say, 1K) to Vcc will suffice. A logical place to add this resistor would be at the DMA controller.
D2. Install resistor R12 (220 ohm, red-red-brn) at location 5E and capacitor C10 (33pF dipped mica) at location 5E. This RC circuit acts as a delay for the CC-DBSL/ signal.
D3. Add an unused inverter to the circuit by connecting a jumper wire between the location labeled PHLDA (location 7E) to 2C pin 11 and another jumper wire from 2C pin 10 to 2D pin 12. Now cut the trace from 2C pin 12 to 2C pin 10.
D4. Add a second inverter to the circuit by connecting a jumper wire from the location labeled CC-DSBL/ (location 4E) to 7C Pins 4 and 5 and another jumper wire from 7C pin 6 to 7D pin
1. Also, cut the trace on the solder side of the PC board between 7D pin 1 and 7C pin 7. This allows memory cycles to start on the condition: PSYNC AND PHI 1 AND CC-DSBL/
D5. On the header at location 7D, be sure the jumper from pin 1 to pin 2 is installed, as it should be for Z80 operation.
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