GGlabs Releases Updated Apple II SCSI Card

Posted by: Bill Martens Date: October 20, 2019 0 Likes 204 Views

GGlabs has announced the release of a new version of their Apple II Apple SCSI Card Clone. According to the GGlabs website,

The Apple II SCSI card from 1986 was one of the first interface cards to attach a Hard Disk Drive to the Apple II line of computers. A2SCSI is a clone of the last revision (rev.C) of the card with a few enhancements to improve compatibility with modern SCSI drives.

The schematics has been reverse engineered from our original Apple II SCSI card revision C. Some of the schematics documentation is still incomplete as our understanding of the hardware is not complete. We also started disassembling the on-board ROM to help the reverse engineering effort.

Small modifications have been made to the original circuit. Termination power is provided to the SCSI bus through D1 and C13. A optional resistor (R14) is added to fix the controller address to 7. The active termination method has been changed from the A2SCSI-A00 to avoid the hard to find UC5606. Now it is implemented using a 2.85V LDO (U18) and two resistor arrays (RP3 and RP4).

GGlabs website

For more information about the card and availability, you can check out the GGlabs website at: https://gglabs.us/node/2071

Author: Bill Martens
A.P.P.L.E. Chairman of the Board and Club president -- Bill worked for the founder, Val J. Golding and A.P.P.L.E. from 1981 to 1982. In 1999, he began archiving the materials which were distributed and sold by A.P.P.L.E.. That project led to the group that remained of A.P.P.L.E. Bill was involved in the financial industry in Tokyo and has over 20 major office infrastructure projects to his name. In March 2001, he retired to write books and to spend more time pursuing personal interests. As the president of the users group, Bill is in charge of distribution of Call-A.P.P.L.E. magazine as well as the organization of this web site. Bill currently resides in Tokyo, Japan and Shelton, Wa splitting time between the places.
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