Apple II, Networking, Raspberry Pi, Vintage

Apple IIgs – Part One

April 21, 2018

Back in January, I answered a CL ad in Seattle for an Apple IIgs ROM01 Computer – $60. The IIgs is a 16bit Apple II Computer. The last Apple II model made before the Mac took over. The “gs” stands for graphics and sound. It has built in Ensoniq synthesizer chip and support for RGB video as well support for 12mb of RAM (maybe more.)
Apple IIgs computers had three similar but different ROM versions, ROM00, ROM01, and ROM03. A summary of how Wikipedia lists the basic differences between the ROMs is as follows:
Original Firmware release ROM00: an early almost beta-like firmware version that shipped with the IIgs for the first year. Early version of System 1.x toolset, and only supported by the OS up to System 3. This ROM would only allow a RAM disk of up to 4mb, no matter how much RAM you had in the computer.
Second Firmware release ROM01: Released in August 1987, this updated ROM was made as a free upgrade to all existing users. It had toolset version 2.x and several bug fixes. Apple and most 3rd party developers stopped supporting ROM00 after this release, making it a vital upgrade for those who had a ROM00 machine. This ROM allowed for RAM disks up to 8mb.
Third Firmware release ROM03: Released in August 1989, Apple increased the on-board RAM to 1.125mb (previous was 256k), changing the motherboard layout and making ROM03 not available as an upgrade. To go from previous ROMs to ROM03 would require a motherboard change. Apple said the reason the upgrade was not being offered was because the same thing could be achieved by a software upgrade to System 5.x and installing a fully populated memory expansion card. There are a lot of things that the ROM03 gave the machine to increase performance. Here is a brief list:

  1. Less power draw
  2. Resolved audio noise issues with the Ensoniq synthesizer
  3. System 5.x toolset on the ROM gave it a huge performance boost
  4. An enhanced ADB micro controller made sticky keys, mouse emulation and keyboard LED support native
  5. Improved compatibility and performance for Apple II video mode

I’m sure there are many more improvements that I didn’t list, but you get the gist.
When I started looking for a IIgs, I asked around on some forums and FB groups and the consensus was really that the ROM03 version was better, but the ROM01 was compatible with more applications and hardware. The ROM01 had a known feedback issue that caused some audio noise to be present.
Well, as I said, I found a guy selling his ROM01 IIgs for $60. Barebones, no cards or accessories, but it worked and had been cleaned. I bought it!


I stopped by my favorite recycling store, RePC and picked up an ADB keyboard and mouse (prices too low to print,) and got home and fired the computer up. Everything worked just like the computer was new, or so I thought – we’ll get to that later.
I connected a serial cable to the machine and connected the other end to my iMac via USB adapter and proceeded to bootstrap ADTPro. (http://adtpro.sourceforge.net/bootstrap.html#Starting_from_bare_metal)

Once I had ADTPro loaded, I needed to make some disks to test the computer more thoroughly. I made a few disks, GS/OS 1.0 System, Ultima I, Kings Quest I, Prince of Persia, basically anything I could verify would run on a stock configuration.
It worked! I was able to boot it up, and play the games and everything was working. I quickly learned how many programs and games for the IIgs required a RAM upgrade, so I purchased a 4mb card from ByteBooster and installed it a few days later.
With a 4mb card, I had enough RAM to run pretty much anything, except that I could not run anything that was larger than an 800k floppy disk, unless it could be ran from a set of floppy disks. I was able to setup an AppleTalk network and get my IIgs to remote boot from a shared drive on my MacSE, which was awesome. I could also map AppleTalk shares from my Raspberry Pi, but I could not boot from that share. Here are the instructions I used for that configuration: http://www.synack.net/~bbraun/iigsboot.html
By remote booting from a shared hard drive, I was able to boot up a fully working GS/OS 6.0.4 and while it did work well, it was very memory hungry and still a bit slow.

Even though I could now load software that was larger than floppy disks would hold, I still felt like I needed a mass storage device, and I knew a great place to get one…

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