One enjoyable component of retrocomputing is that you get to max out all elements of these techniques without having possessing to take out a lender personal loan, as tended to be the scenario when these units have been new. A lot less entertaining is that a long time after systems like the Apple MacIntosh SE/30 were previous offered, the 30-pin SIMMs that type the expandable RAM for these techniques has come to be fairly scarce. This has led a lot of to make their own SIMM PCBs, together with [Kay Koba] with a PCB for 4 MB SIMMs along with details on which memory and parity ICs are ideal for these SIMMs.
For programs like the MacIntosh SE/30 with 8 30-pin memory slots, the greatest potential is 128 MB, but this arrives with several gotchas due to its ROM becoming ’32-bit dirty’. Even though this can be circumvented by swapping in a ROM from a later MacIntosh variant, the significantly less invasive way is to enable the Mode32 procedure extension and set up eight 4 MB SIMMs for a total of 32 MB RAM. RAM chips for this kind of 30-pin SIMMs can be scavenged from the much a lot more widespread 72-pin SIMMs, along with any previous new stock a single could occur throughout.
These 4 MB SIMM PCBs are available for sale by [Kay] with optionally the SMD factors (capacitors, resistors and LED) bundled in the offer. The authentic PCB card edge structure is credited to get the job done by [Zane Kaminski] whose GitHub profile also leads to e.g. this 30-pin SIMM venture.
Have you modded your MacIntosh or other retro method but to the maximum RAM and storage restrictions?