Tag: gal

Modifies an Amiga 1000 to boot Kickstart from four EPROMs while retaining access to its 256 KB daughterboard RAM.

This is an advanced board-level modification, not a plug-in board. It requires a GAL16V8A, four 27C512 EPROMs, a legally obtained Kickstart image, device programming, desoldering, jumper installation, and PCB trace cuts.

• Amiga 1000 Exact model

Recreates the Comspec SA-1000 sidecar to add a SCSI bus and real-time clock to an Amiga 1000.

This is a self-assembly project with a schematic, bill of materials, and fabrication package. It requires programmed GALs and ROMs plus careful alignment of the 86-pin edge connector. The alternate RTC-72421 clock chip is suggested but untested.

• Amiga 1000 Exact model

Recreates the Gravis Ultrasound PnP ISA sound card around an AMD InterWave chip, with an optional IDE CD-ROM interface.

The maker has not fabricated or tested this board and has not generated a fabrication package. It also requires an AMD AM78C201 InterWave chip. Treat it as an experimental design and build at your own risk.

• ISA expansion boards Bus/interface

Redesigns the SE/30 logic board as a buildable replacement with Gerbers, placement data, a BOM, and recreated programmable logic.

• Macintosh SE/30 Exact model

Recreates the 16 MHz 68030 MicroMac Performer accelerator for the Macintosh Plus, SE, and Classic, with an optional 68882 FPU.

Operation has been tested in the Macintosh Plus and SE, but not in the Classic; the maker has not found a socket that securely fits over the Classic's PLCC CPU. Host-specific U7 and SJ2 settings are mandatory. GAL16V8-15 and PALCE16V8-15 parts are tested, while ATF16V8 and other speeds are not.

• Macintosh Plus Exact model
• Macintosh SE Exact model
• Macintosh Classic Exact model

Combines an approximately 16 MHz 68030 and optional 68882 on a compact MicroMac Performer remix made for a Macintosh Plus clone.

The only documented Revision 2 installation is in a Macintosh Plus clone. The author expects an original Apple Macintosh Plus to work but asks users to report results, so stock hardware remains unverified. Installation requires desoldering and socketing the 68000, PLD choice is important, and some software may have distorted audio.

• Macintosh Plus Exact model

Adds a 16 MHz 68030 to a Macintosh Plus with a compact hobbyist-buildable board derived from the MicroMac Performer.

This build requires a PGA 68030, five programmed 16V8 devices, and soldering a socket on top of the Macintosh Plus 68000. The maker does not recommend the System 7.0 GemStart driver, reports garbled or intermittent audio, and warns builders to watch the first SIMM's clearance.

• Macintosh Plus Exact model