Tag: sram

Replaces the Atari 1200XL memory subsystem with 1088 KB of SRAM.

The maker publishes a schematic, Gerbers, and the programmed-logic JED file but no bill of materials. The installation removes twelve socketed chips from the motherboard and transfers four original chips to the upgrade. The RF choke may need to be bent or removed for clearance. Install the 1 mm board only with the motherboard out of its case and supported on a solid surface because the stacked machine-pin sockets require substantial insertion force.

Recreates an Atari 8-bit computer on a compact 4.5-inch motherboard with 576 KB of RAM, PS/2 input, selectable ROMs, and modern daughterboard expansion.

The maker publishes Gerbers, schematics, a BOM, firmware, and case files, and points to The Brewing Academy for assembled systems and boards. The current project page requires a documented oscillator video fix on existing builds.

Raises an Atari 600XL from 16 KB to 64 KB with a compact external parallel-bus module.

The page reported four modules in stock on 2026-07-27. The 600XL supplies the required 5 V through its parallel bus, so this exact module needs no external power supply.

Published 1985 Apple II coprocessor prototype with a 68020, optional 68881, 32K SRAM, and boot EPROM.

Treat this as a historical experimental build, not a safe drop-in design. The creators used custom wire-wrapped and insulation-displacement construction rather than a published PCB. Later design notes estimate roughly 1 A typical and as much as 1.5 A from +5 V even though the Apple II specifies 500 mA shared by all peripheral cards, and they identify excessive data-bus loading. A faithful build needs its own engineering review and likely a redesigned power and bus interface.

Adds CompactFlash storage, cartridge-image loading, and onboard flash and SRAM to Atari XL and XE computers.

The official page showed MyIDE-II cartridges and accessories available on 2026-07-25. A prepared CompactFlash card is offered separately, so confirm the selected package contents. No ROM images are included; users must supply legal images and software.

Replaces the paired 41464 or 4464 DRAMs on later two-chip C64 boards with a modern SRAM module.

Jaystonian showed nine assembled modules in stock at USD 14.99 on 2026-07-29, and Retro Lemon exposed a GBP 17.50 product page without an out-of-stock marker. Assy 250469 is the well-tested target. Jaystonian reports mixed results on 250466, and the open project's author had only tested 250469. Original soldered DRAMs require careful desoldering and sockets before this becomes a plug-in repair.

Adds 512 KB of SRAM to an Amstrad CPC 6128 or CPC 6128 Plus through the Z80 CPU footprint.

The Lotharek page exposed a login-or-register-to-buy path on 2026-07-27. The CPU must be removed or desoldered, the module fitted in its place, and the CPU installed on the module. Confirm pin-1 orientation, socket quality, board clearance, and the computer's condition before beginning the invasive installation.

Replaces Atari 8-bit dynamic RAM with modern SRAM or configurable FPGA-managed PSRAM in three current versions.

All three memory variants exposed login-or-register-to-buy paths on 2026-07-27. Installation goes under the CPU and may require removal or isolation of the original DRAM, desoldering, new sockets, and EXT_SEL or CAS_INHIBIT connections. The Professional version also uses an MMU adapter and its page says to install the latest firmware before use. The optional Freddy Module v2 cannot operate alone: the seller requires the basic SRAM module first and says VBXE owners do not need the Freddy replacement.

Replaces the Z80 and upper 32 KB of DRAM in a ZX Spectrum 48K, Spectrum+, or Timex TC 2048 while adding AY sound.

The seller exposed a login-or-register-to-buy path for MAMLAS on 2026-07-27; its Z80SRAM predecessor is discontinued. MAMLAS installation is invasive: remove the original CPU and any socket, disable or remove the upper 32 KB DRAM, and solder the module directly at the CPU footprint with correct pin-1 orientation. The audio connector is not included, and a ZX Spectrum 48K heat sink may need to be bent for clearance. Do not install the module on top of its shipping or protective bottom socket. Used Z80SRAM boards should be treated as a distinct earlier revision and checked against their archived instructions.

Builds a compact modular IBM PC/XT-compatible computer with an 8088 or NEC V20, up to 640 KB of base RAM, optional upper memory, and 8-bit ISA expansion.

The GPL-3.0 project provides KiCad files, Gerbers, a bill of materials, BIOS, programmable-logic files, and build instructions. Retro Electronics had six bare ENIG PCBs in stock on 2026-07-27; every component and all assembly are excluded. Weird Electronics' board and complete-kit listings were temporarily unavailable while the seller takes a break through August 20, 2026. A separate assembled-board listing had been sold out since May 11, 2026. Weird Electronics sells a Version 1.4 PCB with larger Flash-ROM support, while the repository README documents layouts through Version 1.3; follow the documentation for the board actually supplied.

Recreates the 1986 Soviet Radio-86RK home computer on one board with an Intel 8080A, 32 KB of SRAM, integrated keyboard, monochrome composite video, cassette, serial, and parallel interfaces.

The GPL-3.0 repository provides Version 1.4 KiCad files, Gerbers, a bill of materials, monitor and font ROM images, project notes, and archived original magazine material. Weird Electronics' bare-PCB listing was temporarily unavailable while the seller takes a break through August 20, 2026; when active, it includes only the main PCB and two ROM-cartridge PCBs. This is a large through-hole build requiring several vintage Intel 8xxx or compatible chips, 67 key switches, programmed ROMs, and regulated power. The Tindie heading incorrectly calls it an Intel 8088 computer; its own detailed specifications and the project repository correctly identify an Intel 8080A.

Open ATmega328P bench tester that automatically identifies and checks a broad range of vintage DRAM and 2114 SRAM.

The repository was active on 2026-07-20 and documents firmware 5.0.7. It links ready-made routes at AmiBay, Lectronz, eBay, and Tindie plus a PCBWay through-hole board, but those sellers were not independently checked for stock in this pass. Hardware is CERN-OHL-S v2 and firmware is GPLv3. Builders may use through-hole or surface-mount files and must select or build any required adapter for the exact package.

Adds 128 KB of low-power Saturn-compatible bank-switched RAM to slot-based Apple II systems.

The assembled Tindie card was out of stock on 2026-07-24 and had been sold out since March 14, 2025. The open repository provides schematics, KiCad files, Gerbers, and documentation. In an Apple IIe or IIgs this is not normal auxiliary or fast memory; only software that understands a Saturn-type card in a peripheral slot can use it.

No-solder SRAM daughterboard that expands a Commodore 16 or 116 to 64 KB and can switch back to 16 KB.

Poly.play listed the board as out of stock on 2026-07-30. The earlier direct AmiBay sales thread is closed. Use PCB revision 1.4 or later: the maker reported an error in revision 1.2, refunded those boards, and said revision 1.4 was corrected and tested with Diag264. A reset is required after changing the 16 KB / 64 KB selection.

Compact, low-power C128 VDC video-memory expansion built around one 64 KB static RAM chip.

Poly.play listed the pxlmod board as out of stock on 2026-07-30. An older Protovision order link now reports that the product is not found, so check Poly.play for a restock. Current wording names the Commodore 128(D) without separating plastic C128D from metal C128DCR; the latter normally already has 64 KB of VDC memory.

Adds cartridge-based CompactFlash or SD storage, SpartaDOS X, a real-time clock, and loader functions to Atari 8-bit systems.

Lotharek marks both generations discontinued. SIDE2 needs at least 128 KB for its FDISK workflow, and full ATR loading requires Ultimate 1MB. Some systems need a faster 74F08 or buffered O2 timing path. Lotharek ended SIDE3 sales because it could not supply firmware that worked reliably across all computers; Revision 3.2 uses a Gowin FPGA, needs its matching firmware and programming path, and does not accept the older CPLD updates. Identify the exact hardware and firmware revision before buying or flashing a used cartridge.

Publishes an experimental 1024 KB plus 64 KB SRAM expansion board for the Atari 600XL and 800XL.

The author labels the April 2025 post UNDER WORK and calls it a placeholder. A KiCad archive containing the stated schematic and Gerbers is downloadable, but the page provides no bill of materials, assembly guide, firmware, electrical test results, completed installation report, or explicit license. Treat it as an unfinished engineering project for experienced builders, not a validated kit.

Replaces the C16's original DRAM and multiplexers with a socketed SRAM module that can select 16 KB or 64 KB operation.

The maker's 2024 article still links a SellMyRetro offer and says kits are available, but current stock was not independently established on 2026-07-29. This is explicitly an expert installation: four ICs must be removed without damage, four sockets fitted, and A14, A15, and phi-0 signals connected. The maker warns that it is not a beginner project.

Experimental C64 replacement motherboard with three SID sockets, optional internal storage and sound modules, ROM switching, and extensive test points.

On 2026-07-30, UNI64 listed the bare v4 PCB at EUR 32.50 as a three-week preorder and the READY+ board at EUR 345 with a five-week order lead time. READY+ includes standard logic, the 8701, and 64 KB RAM but excludes all named Commodore-specific chips and the required 12 VDC 2 A supply with a 2.1 mm inner-diameter barrel plug. Optional Pi1541, MIDI, FM OPL2, and SSD hardware is not included. The bare page labels its feature list as Version 3 even though the product and files are v4; the linked v4 info PDF remained unreadable after the required retry under WF-071, so confirm version-specific assembly details from the supplied documentation.