Macintosh Plus upgrades

Open hardware SCSI emulator with SD-backed storage, optional Wi-Fi networking, and host-side management tools.

For this system (exact model): The official documentation requires the Mac Plus configuration file and external power over USB or a termination-power diode modification. The Plus normally has only an external DB-25 SCSI port; an adapter such as Clipper Plus can add an internal connection and cable-supplied termination power.

Current seller checks on 2026-07-27 found a $39 internal 50-pin Pico 2 W kit, a $49 assembled external DB-25 model, a $49 PowerBook model, and a $59 assembled Ultra Narrow 50-pin model at authorized seller ToTs RETRO. JCM also carried assembled Ultra hardware and model-specific Macintosh adapters. Prices, stock, included media, and support differ by seller. Ultra models require Berg or Molex power and cannot run from SCSI termination power. The initial Ultra hardware release is not yet open hardware, although its firmware remains GPL; the project says hardware licensing will open later.

Turns a spare compact-Mac logic board into a small desktop computer with modern power, display, and storage hardware.

For this system (exact model): JCM sells a Plus enclosure and GutBomb includes the Plus in the printable design. A complete build needs the donor logic board plus model-appropriate power, video, storage, input, and display hardware.

On 2026-07-24 JCM showed 5 printed 128K/512K cases, 3 Plus cases, 2 SE/SE30 cases, and 5 Classic/Classic II cases in stock. This is an enclosure, not a complete computer: supply a working logic board, power and video electronics, storage, input devices, display, cabling, and other desired parts. GutBomb's printable design is CC BY-NC-SA and does not cover the separate electronics.

Adds an internal SCSI connection and termination power to a Macintosh Plus by clipping over its SCSI controller chip.

For this system (exact model): Clipper Plus presses over the Macintosh Plus SCSI chip. Keep it squarely and fully seated while reinstalling the logic board: friction from the tightly routed cable can dislodge it, causing the Mac to miss the device or behave erratically. Opening the case requires a long T15 Torx driver.

The JCM page showed 18 units in stock on 2026-07-24. Installation requires opening the compact Macintosh, removing and reinstalling its logic board, routing a SCSI cable through a tight chassis gap, and supplying a separate SCSI device.

Replaces missing or broken case-mounted programmer's switches on compact Macintosh computers.

For this system (exact model): The Macintosh Plus is explicitly named. The part replaces the removable programmer's switch rather than adding a new electrical function.

Both product pages said Sold out or Out of Stock on 2026-07-27. The Greeny-switch resin can break if excessive force is applied. Choose the model-specific variant; neither seller establishes cross-family interchangeability between the early compact-Mac and SE-family switch assemblies.

Uses an SD card to emulate Apple floppy drives and, on supported systems, HD20 or SmartPort hard disks.

For this system (stated family): The manual covers classic Macintosh systems in this generation. Install the Macintosh/Lisa firmware, connect through DB-19 or the documented internal header, and choose a floppy or HD20 image mode supported by the host.

The BMOW store showed the assembled Model C sold out at $109 on 2026-07-27. The separate Deluxe bundle is the same emulator packaged with accessories rather than a different product family. Check the direct product page for a restock.

Current and buildable replacement ROMs for early compact Macs with a customizable bootable ROM disk and HD20 support.

For this system (exact model): Supports Macintosh Plus systems. Assembly is through-hole but requires removing the original ROMs and installing closely spaced sockets and headers.

On 2026-07-24 JCM showed eleven 128K/512K modules and nine Plus modules in stock. Infinity Products also listed standard and spare-ROM kits without an out-of-stock marker. Installation requires opening the Macintosh, removing its ROMs, and soldering three or four address and write lines to the mainboard. BMOW provides the original parts list, Gerbers, assembly instructions, Flash Tool, and ROM data.

Adapts modern USB keyboards and mice to early Macintosh keyboard and mouse ports or to ADB.

For this system (exact model): The Plus is explicitly included in the early RJ11 keyboard and DB9 mouse group. The dedicated ROM-boot button avoids normal USB-to-vintage initialization delay.

The current page listed a fully assembled unit without an out-of-stock marker on 2026-07-24. Firmware and hardware are closed source. USB peripheral and hub compatibility varies; early iMac Rev. A through C USB keyboards are explicitly unsupported.

Converts raw compact-Mac video to VGA, with optional power integration for bare logic-board projects.

For this system (exact model): The standalone MacPicoVid boards explicitly list the Macintosh Plus and require separate 5 V USB power plus raw video and sync wiring. A power-integrated CatMac build instead uses the SE-COMBO with JCM's 128/512/Plus J8 adapter.

On 2026-07-24 JCM showed 11 onboard-VGA and 41 Extended MacPicoVid boards, 56 MacPicoVid SE-COMBO boards, 2 IDC12 boards, 19 SE-TOPPER boards, 46 128K/512K/Plus adapters, and 32 Classic adapters in stock. Standalone boards require separate 5 V USB power and host wiring. The power-integrated products are for a removed logic board or custom chassis, not a drop-in external-video port for an intact computer.

Upgrades compact Macintosh computers with a 16 MHz 68030 and optional 68882 FPU through original vintage cards or modern recreations.

For this system (exact model): The original Performer used an included clip over the Macintosh Plus 68000, and the modern clone is tested in this model. For the clone, U7 must be installed and SJ2 must remain open.

The open clone remains buildable, but MacEffects' assembled Macintosh SE variant was sold out on 2026-07-27. The original MicroMac page was last modified in 1998, so its order form and prices are archival rather than a current purchase path. Modern-clone operation has been tested in the Macintosh Plus and SE, but not in the Classic; no secure socket has been found for 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.

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

For this system (exact model): Designed for the Macintosh Plus form factor, but tested only in the maker's Plus clone. The stock Apple model is an intended target rather than verified compatibility. The source says stock ROM and VIA changes should not be necessary, but it does not report a completed stock-Mac test.

Human review confirmed that the JCM Edition was in stock on 2026-07-24 and that JCM offers the CPU and FPU as a separate linked item. The open project and bare-PCB path remain available. Confirm the Edition's exact assembly state and mounting-clip contents before ordering. Installation requires access to the 68000, PLD choice is important, and some software may have distorted audio.

Open, reversible Pico ATX power-adapter family for the Macintosh 128K, 512K, Plus, SE, and SE/30.

For this system (exact model): The early compact-Mac adapter explicitly supports the Macintosh Plus and plugs into the logic board to bypass the original AC/DC power conversion. Follow the project instructions, use the correct cable routing and fuse values, and observe compact-Mac CRT high-voltage precautions.

On 2026-07-27, the 128K/512K/Plus listing showed order controls at $29.99 and the SE/SE30 listing showed order controls at $34.99. Both offered kit and assembled choices. Their United States shipping sections simultaneously displayed rates and a does-not-ship warning, so confirm destination availability at checkout. A suitable PicoPSU and adequately rated 12 V center-positive power brick are separate parts.

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

For this system (exact model): Designed and tested only for the Macintosh Plus. The maker verified System 6.0.8 and System 7.1, using the matching GemStart Universal version and selecting Total Systems Mercury during installation. System 7.0 is documented but not recommended.

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.

SD-card storage adapters for notebook SCSI, internal 50-pin SCSI, and external DB-25 SCSI connections.

For this system (exact model): The external PowerMonster with BakMonolith product explicitly names the Macintosh Plus. The Plus requires a separate 5 V external power adapter because its SCSI port does not provide the required termination power.

The standalone PowerMonster, AztecMonster, and SusanoMonster pages exposed current Add to cart controls on 2026-07-24. The external PowerMonster with BakMonolith kit was out of stock. Mac OS installations need suitable third-party formatting software. Hot swapping works only when the host operating system supports removable media and may require explicit unmount and mount operations.

Breaks out compact Macintosh internal TTL video for an RGBtoHDMI or another compatible digital scaler.

For this system (exact model): The product page explicitly names the Macintosh Plus. Installation uses internal analog-board video signals and requires a compatible external scaler.

JCM showed 11 units in stock on 2026-07-24. This is not a standalone HDMI adapter: it requires a compatible digital-TTL scaler and installation wiring. The onboard buffer is intended to protect the scaler from analog-board high voltage.

Open-firmware SCSI emulators in DB-25, internal 50-pin, laptop, and Wide SCSI form factors.

For this system (bus/interface): The product is designed for direct attachment to a DB25 SCSI port, and the Plus provides external DB25 SCSI. The maker says TinySCSI fits flush on compact Macs. A Pico Slim must be the final device because its termination cannot be disabled.

Rabbit Hole Computing offered current Compact RP2040, Blaster, and Wide variants on 2026-07-24. A 2026-07-27 follow-up found its mostly assembled $25 Pico Slim V1.3 PCB kit sold out, while SamplerZone exposed an Add to Cart path for a $79.95 assembled and cased Pico Slim with configured microSD media. Rabbit Hole's direct Pico2 Slim and Laptop Blaster pages were also sold out. TinySCSI was archived in January 2025, but its V1.0 and V2.0 KiCad files remain available for personal builds. A project discussion documents Wi-Fi DaynaPORT operation on a Pico Slim under System 7.5.5 with the DaynaPORT SCSI-port driver, but does not establish a minimum System version or equivalent networking support for every family variant. Connector, termination, power, speed, and initiator support vary by hardware.