{"id":25015543,"url":"https://github.com/hkzlab/ps1_pu22_8mb_mod","last_synced_at":"2026-01-08T15:06:33.140Z","repository":{"id":254298256,"uuid":"846048999","full_name":"hkzlab/PS1_PU22_8MB_mod","owner":"hkzlab","description":"A daughterboard to install 8MB of addressable RAM to a PU-22 based PS1","archived":false,"fork":false,"pushed_at":"2024-08-22T14:51:55.000Z","size":2946,"stargazers_count":6,"open_issues_count":0,"forks_count":0,"subscribers_count":1,"default_branch":"main","last_synced_at":"2025-02-05T08:36:47.557Z","etag":null,"topics":["expansion","hardware","memory","mod","playstation","ram"],"latest_commit_sha":null,"homepage":"","language":null,"has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/hkzlab.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2024-08-22T12:43:05.000Z","updated_at":"2025-01-31T17:41:25.000Z","dependencies_parsed_at":"2024-08-22T16:46:48.535Z","dependency_job_id":"4830977a-be7c-4024-93fd-65876ba198fd","html_url":"https://github.com/hkzlab/PS1_PU22_8MB_mod","commit_stats":null,"previous_names":["hkzlab/ps1_pu22_8mb_mod"],"tags_count":0,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/hkzlab%2FPS1_PU22_8MB_mod","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/hkzlab%2FPS1_PU22_8MB_mod/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/hkzlab%2FPS1_PU22_8MB_mod/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/hkzlab%2FPS1_PU22_8MB_mod/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/hkzlab","download_url":"https://codeload.github.com/hkzlab/PS1_PU22_8MB_mod/tar.gz/refs/heads/main","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":246285653,"owners_count":20752947,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["expansion","hardware","memory","mod","playstation","ram"],"created_at":"2025-02-05T08:30:27.609Z","updated_at":"2026-01-08T15:06:33.134Z","avatar_url":"https://github.com/hkzlab.png","language":null,"funding_links":["https://ko-fi.com/hkzlab"],"categories":[],"sub_categories":[],"readme":"# PlayStation PU-22 8MB RAM Daughterboard\n\n## DISCLAIMER\n\nAny use of this project is **under your own responsibility**.\nYou will be responsible of checking the correct construction and functionality of your board.\nBy using this project You will agree that I cannot be held responsible if it will destroy any of your devices, damage your computer, burn down your house or whatever.\n\n## Introduction\n\nThis daughter board replaces the single main RAM IC on your PU-22 motherboard with 4 2Mx8 ICs, shuffles some address lines and provides your PlayStation with 8MB of addressable memory.\n\nI tested this on my european SCPH-7502 console, with a PU-22 motherboard in it. The board boots fine and all the 8MB are addressable.\nIt could work on other models too, but as of now, this is the only tested one.\n\n### Support\n\nIf you wish to support me in building new hardware and software for old machines, [throw a few euros in my direction via Ko-Fi](https://ko-fi.com/hkzlab) ☕!\n\n## Hardware\n\nThe board was designed with [KiCad](https://kicad.org/) EDA.\n\nThe board **MUST** be produced on a flexible PCB!\n\n### Installation instructions\n\nDisassemble your PlayStation, extract the motherboard and make sure the model is a PU-22.\n\n⚠️WARNING⚠️: This mod probably works on all units with this type of RAM and processor, but it has been tested on PU-22 units only, as of now.\n\nAssemble the daughterboard, soldering caps and memory ICs.\n![RAM + Kapton around it](pics/00_daughterboard.jpg)\n\nDesolder the inner shield covering the main ICs, including the RAM.\n\nCover the components around RAM \"IC106\" with kapton tape, to protect them during desoldering.\n![RAM + Kapton around it](pics/01_install_kapton.jpg)\n\nDesolder the RAM IC using hot air, then clean the pads using flux and solder wick.\n![RAM desoldered, pads clean](pics/02_install_clean_pads.jpg)\n\nSolder the board to the old RAM pads, make sure to solder the board in the correct orientation. Pin one has a tiny arrow printed on it, match it on pin 1 on the motherboard.\n![soldered pads](pics/03_solder_board_pads.jpg)\n\nYou now need to solder two wires to the CPU, to extract A10 and A8. A10 is pin 56, A8 is pin 58.\n![address line soldered](pics/04_additional_address_lines.jpg)\n\nYou can then solder these lines to the pads with matching names on the daughterboard.\n\nYou can now reinstall the shield, but before inserting it, bend inward the part of the shield that went through the PCB near the RAM pad, make it almost flush to the shield, so it doesn't block the way for the daughterboard to get out.\n\nOnce reinstalled, cover the part of the shield where the daughterboard will sit with tape, so there is no chance of shorting.\n![daughterboard installed](pics/05_installed_daughterboard.jpg)\n\nSolder the daughterboard GND pad to the shield, use rigid wire so it keeps the daughterboard in place.\n\nYou can put tape over the daughterboard too, to avoid shorting, then reassemble the unit.\n\n### Bill of Materials\n\n| Component         | Qty | Type / Value                   | Notes                                                    |\n| ----------------- | --- | ------------------------------ | -------------------------------------------------------- |\n| C1 - C4           |  4  | 100nF / 1206 / ceramic         |                                                          |\n| U1 - U4           |  4  | KM48V2104ALT-6                 | Compatible memory can be used                            |\n\n### Ordering the boards\n\nYou can order the board for this project at [PCBWay](https://www.pcbway.com/project/shareproject/PlayStation_PU_22_8MB_RAM_Daughterboard_6c497b7f.html) and support me or download \nthe gerbers and have them printed wherever you like!!!","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fhkzlab%2Fps1_pu22_8mb_mod","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fhkzlab%2Fps1_pu22_8mb_mod","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fhkzlab%2Fps1_pu22_8mb_mod/lists"}