MFM hard drives use those terminators. Pulled out one and it uses Beckman 898-5R220/330. Your Dale part looks the same. These give termination impedance of 132 ohms which is around ribbon cable impedance and set the high level of 5*330/(220+330) = 3V. On Sun, Aug 06, 2023 at 10:21:00PM -0400, Mike Loewen via vcf-midatlantic wrote:
Does anyone have a part number for the terminator resistor pack for a Shugart 860? The only part number in the service manual is a Shugart number (16837) and the schematic is less than helpful. It's a 14-pin DIP, listed as a 220/330 ohm. It's possible that it's a Dale MDP1405-221/331G, but I'm not sure. The schematic shows pin 14 is a common pin, connected to +5V. Any help would be appreciated.
Mike Loewen mloewen@cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/