Scsi Case

Date: 3 Feb 1994 15:35:54 -0600 From: "Glockzin Donald" <Glockzin_Donald@macmail1.fwrdc.rtsg.mot.com> Subject: Submission: SCSI_Case1.1.txt This is a text file that describes how to build a case to hold multiple internal SCSI devices using a PC case. The cost is around $100 (US) and can hold 4 or more devices. The text file gives possible part numbers and hopefully answers possible questions from the average user. My system has been working for >3 months without any problems. If interested, read it. Flames accepted, but you should at least read it first. I am the author. (This can be included in any non-commercial package.) THANKS -- DG Donald Glockzin Lead Engineer Motorola - CIG glockzin_donald@macmail1.ftw.rtsg.mot.com ____________________ cut here ________________________________________ SCSI CASE 1.1 Using PC Case to hold SCSI Devices for a Mac system. INTRO: The price difference between internal and external SCSI devices is about $50 to $100. The cost to build a case to handle numerous internal SCSI devices can be under $100. This will reduce the cost to add other devices. This report should explain the cost, the material, and the work required to complete this task. CONCEPT: External SCSI devices come with a case, a small power supply, a loop-thru SCSI connection, and maybe some type of termination. The PC case will provide the mounting and the power supply for multiple SCSI devices. One ribbon cable assembly is required to connect the devices together and to the rear of the case. A shielded SCSI cable can be purchased to connect the Mac to the PC case. The last device on the chain in the PC case will need to terminated. If other SCSI devices that will not be in the PC case are used, they will need to be located between the Mac and the PC case on the SCSI chain. MATERIAL: 1) PC Case - a mini-tower case with a 250W or more power supply can be purchased for <$60 ($45 is a good price new). It should come with miscellaneous hardware for mounting the devices. The power supply should be prewired with connectors for providing power to numerous SCSI devices (typically 4 or more). 2) External SCSI Cable - a DB-25 to 50 pin centronics for about $15 3) 50 Pin Ribbon Cable - 5 feet or less. The quality is up to the buyer and starts around $1/foot. (Digi-Key R028-5-ND is $4.79 for 5 feet) 4) 50 Pin Centronics Connector - the external connector on the PC case at one end of the ribbon cable. (CHAMP Latch Bail Lock - Amp # 553603-1; Digi-Key A1569-ND $5.20) 5) [Optional] Bail Lock Hardware - the hardware to lock the centronics connectors together; other methods like screws can be used. (Amp # 552561-3; Digi-Key A1517-ND $1.67) 6) 50 Pin Socket Conn with Polarizing Key - the connector that snaps onto the ribbon cable where needed. If you have five devices, you need five connectors. (Amp # 1-746286-0; Digi-Key AKC50T-ND $3.57) 7) [Optional] Strain Relief for part #6 - at least one should be used for the end of the cable, but the re…