Applied Engineering: Z-RAM II for Apple //c

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Bought one Apple //c few years ago with Z-RAM II-card installed but i could not get it working. It had broken pins and some were replaced with wiring. It could not get it running so i sent to to Henry Courbis at reactivemicro.com for repairs. He did splendid job and got it working in notime! Big thanks to Henry!

 

What is it?

Z-RAM II is combined co-prosessor and memory expansion card that can be expanded from 384k to 1024k. The basic comfiguration is 256k (soldered to board) so you get 384k of RAM with basic setup. The expanded memory can be used in programs like AppleWorks and many others as well as high-speed solid state (RAM) disk. The card have also a Z-80 prosessor on it so it can run programs from large CP/M program library. The card was originally supplied with CP/AM 4.0B disk.

 

Installation

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The installation is fairly easy. Obiously needed to open the //c and then needed to remove the disk drive and the keyboard to have good access and have everything in sight.

-CPU -> removed and moved to empty socket in Z-RAM II  
-MMU -> removed and moved to empty socket in Z-RAM II  
-Also needed to attach the “pin grabber wire” to TGM chip (pin 2). I found out that the cable had to be covered with tape in order not to intefere the belt of the floppy drive.

Then just insert the card (carefully!) to the sockets of CPU+MMU by pressing the card down. i tried to take extra care and not to bend any pins.

There were one additional connetor for extra RAM but at the moment i do not have such RAM module that would work in this card.

 

Usage?

So what could be done with it then? Addional memory for the AppleWorks usage is obious, if that’s something you would be still doing, as well using the extra memory as RAM-disk – but maybe using the CP/M is more usefull, or is it? Depends your interests. 

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Running CP/AM 4.0B

ramdrive_dos_s
RAM-Disk DOS 3.3 options.

ramdrive_prodos_s
RAM-Disk (ProDOS) options.

 

ram_test_s
There’s also RAM-test to ensure your card is running with all RAM working.

I must admit this card is more like collector’s piece, actual usage might be quite limited. But running CP/M is kind of cool with the Apple //c. Ramdrive is quite handy only if it would be backed with battery.. this system had ROM0 on it, i could upgrade it to the custom ROM to have more options enabled.

 

FinApple 2019 (c)
Apple //c Forever.