512K Mac Reminiscences

This machine appeared incredibly powerfull to someone like me who was used to shoehorning all of their programs into the 56Kb address space of a PDP-11. The down side of the Mac was that only floppy disk storage was available when I was used to having a couple of refrigirator sized 66 Mb hard disks and a tape drive attached to the PDP-11/44 at my disposal the year before. Nevertheless, the 400 Kb or so of RAM I had at my disposal in 1988 seemed like a massive amount.and the neat thing was that all of this power was in a tiny package that I could use on a tabletop in my Calgary apartment instead of having to go to my UBC lab where the PDP-11 had its own air conditioned room for its various components.

The absence of a hard disk drive caused some distortions in my programming style that are obvious only now, but the Software Tools influence is clearly evident in the sequential application of various simple programs to fingertapping data which was the primary use I made of the Macintosh platform from 1988-1992.

I now own the PDP-11/23 which served as a slave processor to run my data acquisition code, but I don't own my early Macs. The 512K Mac I got from my father and his MacPlus were sitting in the basement of my parents house in Victoria until April 2001. Both my parents are dead now and I went through the contents of their house from August 2000 to April-2001. The MacPlus of my fathers was upgraded to 4 Mb of RAM in 1989 at a cost of $700. He had retired this machine in 1990 in favor of a Mac IIvx which I still own and it operates at the, incredibly fast for 1990, frequency of 33 MHz.

Around January of 2001, I installed the Mac emulator Basilisk II on Loki, my newest computer which is a 900 MHz Athlon processor with 384 Mb of RAM and 60 Gb of HDD storage. The emulated Mac I was interacting with ran around 30 times faster than my hardware Mac IIvx which I bought in 1993. I didn't even want to compute how much faster Basilisk II was than my 512 Kb Mac of 1988. I wanted to keep these old Macs, but there was nothing about these machines that couldn't be emulated in software. My PDP-11's are different in that these machines can still serve a usefull data acquisition function as I have A/D, D/A and digital I/O boards for them that can be used to create systems that operate in hard realtime, not the embarassingly slow interrupt response times that windoze machines can offer. The Mac was not expandable and my only interfacing was done through the serial ports; this can just as easily be done through Basilisk II's emulation of the Mac serial ports on an AT class machine; the ports are RS-232 rather than RS-422, but I can hack the hardware to interface to either.

In short, I ran out of arguments why I should preserve the old 68000 based Macs. The best I could come up with was that this was the Mac I sat in front of in December of 1988 when I contemplated the 20th anniversary of the first human orbiting of the moon on 24/12/1968. My ruminations from that night have long since been transferred from their old Mac Word format file on an 800 Kb Mac floppy to multiple copies on both HDD and CDR as well as laser printed paper which can be rescanned and have OCR done if necessary. In short, the Macs could go.

It was with great reluctance that I dropped both machines off at the Victoria Salvation Army depot at the end of April 2001; I hope they have both gone to good homes where they can be appreciated.