Recent content by wskjinfen

I've observed that the Macintosh Plus's memory mapping has many fragmented free segments after the RAM, totaling over 7.8MB. If I were to use two of the larger-looking segments to create 4MB of RAM, creating a mapping structure of 4MB + ROM & IO + 1MB + IO + 3MB, would the additional 1+3MB of...

Thank you very much for clearing。I’ll give it a try.

Thanks, I need to restore the disk to function without the old parts.

Thanks, I've seen this document before, but it's for Apple IIC IIGs (probably 343-0041). I've heard it's different from Mac's 344-0041. Can Mac use 343-0041? If so, I'll refer to this document. I just started studying IWM, so please forgive me if I ask stupid questions.

Hello😀, do you have the communication protocol documentation for the IWM (344-0041-B)? I haven't found a complete guide online, and I'd like to try rebuilding the IWM myself using an MCU or FPGA to repair Mac 128K and Plus motherboards.Thinks.

I'd like to rebuild it (e.g., using an MCU or FPGA) to fix the IWM issue on MacPlus.Currently, all I can find is information about the Apple II's 343-0041-B, but not the complete communication protocol.Any help would be appreciated.

“chime but no screen”100% of the problems are with the pin header welding.

I am now troubled by the 4116 DRAM which is easily damaged and difficult to buy. I hope to use 62256 and other easily available SRAM to form at least one row of DRAM for Apple ii. Is there any solution?

There is a fuse in the cable connecting the logic board and the analog board. Check if it is blown. Flup-flup can be caused by too small load current or too high output voltage of the switching power supply.

QAQ ok thanks

Is it possible to generate the RA10 signal by some method, and do I need to consider the refresh issue? If this is possible, does the ROM need to be modified?

The Macintosh power supply cannot be unloaded and requires a minimum resistance, otherwise the overvoltage will trigger the crowbar circuit and cause flip-flip. When repairing, you can temporarily connect a 10 ohm cement resistor between +5V and GND and a 20 ohm cement resistor between +12V and GND.

Please eliminate the short circuit of the motherboard first check whether the connection wires between the logic board and the main board and the fuses on the connection wires are blown. “clicking sound at approximately 4.2 Hz”means the switching power supply is unloaded

This kind of socket is universal and can usually be easily purchased through the shopping platform in your country.

Pico-mac is an interesting project. I want to make it more realistic: after ejecting the disk in the system and manually replacing the SD card, it can automatically mount the disk (or trigger the loading by GPIO switch), just like changing the disk on a real mac 128k. I am not familiar with mac...