Apple IIe – Booting A Z80 Microsoft Softcard Clone
So this card was part of the recent bundle'o'Mac and I honestly thought it was just a lowly 80-column text module. Turns out it's a lot more than that! Sure, it's a clone, but it happens to be a Z-80 SoftCard, based on the Microsoft Softcard.
It seems that you need to slap it in slot 4 or 7 and boot relevant software... let's give it a go!
Hardware Installation
Before we get near the machine, let's reset the card to factory default! Make sure all four dipswitches are in the OFF position, as per the photo above. Just for fun, here's the meaning of the four switches, in case you need to tinker:
Switch | Function when ON |
---|---|
1-1 | Disable address translation. |
1-2 | Higher priority DMA devices cause SoftCard to relinquish bus. |
1-3 | Pass NMI line to Z80. |
1-4 | Pass IRQ line to Z80. |
Finally, don't forget to clean the edge connector with isopropyl alcohol, just to make sure there'll be no issues with conductivity once inserted.
Next, we need to get to the innards of your computer. Fortunately, all machines in the Apple II line-up make this part really easy. Make sure everything is turned off and remove the top cover from your machine. Regardless of your model, it'll be two clips at the rear of the top panel.
We're going to choose Slot 4 for this card...
It's the slot directly to the right of the 'Auxiliary Slot' and the card only fits one way. Once inserted, you can either leave the case open so we can see the LED turn on when the card is alive... or work in a clean environment and close everything up!
Software
Before booting up, I'd recommend a full review of the CP/M reference. As with everything Apple II, we'll need a boot disk to get started. For today's post, we'll be using Microsoft Softcard CP/M Disk #1 in Drive 1. Thanks to this machine having two floppy drives, we can also insert whatever-we-want-to-run in Drive 2.
The CPM disks were written using ADTPro via serial from my Windows 11 laptop. I then slapped the first one in the first drive and cold-restarted the machine.
It was a beautiful site, albeit a little underwhelming. I initially had the case off and watched the monitor whilst the unit (very quickly) booted. I then looked back into the chassis of the Apple IIe and the LED on the Z80 board was dark... was it even used? I mean, the fact that CP/M was booted, and displaying on the monitor, should've proven that it did work... but no LED made me sad. I then typed dir...
And, yey! We're in DOS... no more weird Apple OS. Second yey was that... out of the corner of my eye, I saw the LED on the Z80 card flicker! So it only illuminates when it's being used? I rebooted the machine, watching the LED this time, and saw that this was the case: the LED flickered along nicely as CP/M booted.
We're up and running, what next?
Someone on Reddit already asked the question and a great answer was provided: ZORK! Can we boot from Drive A: and play from Drive B:?
Ooops... sorry, that was loaded from A:\. Here's a sample from B:\...
Or write a novel like George on WordStar 4.0. Don't forget to also try and recall your Douglas Adams Knowledge and boot up The Hitchhikers Guide to the Galaxy (1984, Infocom).
It works!