When you fill your office with vintage Macs, your co-workers might get the impression you collect them. Last week, a co-worker of mine brought me a Performa 640CD (DOS). Because this is one of the few DOS-compatible Macs made, I was glad to add it to my collection. After my initial inspection, I decided almost immediately to clock-chip it. It had a 68LC040 CPU running at 33Mhz. After consulting Marc Schrier’s excellent clock-chipping resource page, I found that I only needed to move two surface mount resistors on the logic board. I did this quite easily with a nice soldering iron. When I reassembled the machine, it almost completely booted the first time. I had to go back and add a heat sink I pried off of a Pentium 200 chip. Now, I have no instability. I installed DOS 7.1 on it and it’s running well. I want to replace the DX2-66 486 chip with a 100Mhz 486, but that may add to the heat too much. Add one more overclocked Mac to my collection!

A friend of mine recently gave me an old magazine he found as he was cleaning out his house. It is the August 1986 issue of Ahoy! magazine, a magazine for Commodore users. While I was too young at that time to be an Ahoy! reader, I very much enjoyed taking a look back at the history contained in this old magazine. There were articles about BASIC and assembly language programming for the C64 and C128 as well as an article on the new Amiga 1000! I was particular amused by an ad for SEXTEX, “The nation’s leading erotic computer communications network.” It’s really sad, but I somehow find it interesting how “adult” entertainment goes back so far in the history of computing. $12.95 apparently bought you a lifetime membership to this service. “Call or write for your FREE brochure — your computer will never be the same.” Indeed.

I installed MS-DOS 6.22 and Windows for Workgroups 3.11 on my new Performa 640CD machine. It was a great trip down memory lane. It had been some time since I had seen a true DOS prompt and even longer since I had seen WFW 3.11. I was finally able to install Tie Fighter! It runs great on the little 486 PC built into this great machine. Sound and video both work great, and I’m waiting to dig up an old PC joystick so I can really play the game like it was meant to be played. I was also able to get two other great DOS games to run — Scorched Earth (Scorch) and Stunt Island. Both ran just like I remembered them. It was a great feeling to fire a crazy bomb at the computer tank across the screen and take my Cessna 172 for a spin around the island.

The more I play with this whole DOS compatible Mac, the more I’m amazed by it. It’s just remarkable how well engineered it was. I can share the Mac’s modem port with the PC as COM1 or COM2 and use my ADB-powered Mac Supra Modem from software on the PC, such as Telix. Not only that, but I can use the Mac’s ethernet card as a network adapter on the PC side! Apple provides drivers for DOS/Windows that allow you to share the Mac’s ethernet card and connect to your Windows / Netware network. I’m truly impressed.

Anyway, I’m definitely going to keep this machine around as it is truly the best of both worlds!