PowerPC Emulation and Using a Mac IIcx for Shared Internet Access

1998 – Mac Daniel will be enjoying the New Years holiday with family. The next column will appear on January 4, 1999.

Can a 68K Mac Emulate a PowerPC Mac?

CJ writes: Are there any software patches, such as Wish I Were, that will allow PPC only applications (i.e. Word 98) to run on a 68k Mac?

Mac Daniel writes: No. Emulating one processor on another is CPU intensive. The PowerPC can emulate a 68k CPU because it’s so much more powerful than the 68k family – and because AIM (Apple, IBM, Motorola) designed the CPU for ease of running 68k emulation.

As for software emulation, while it’s theoretically possible to write an emulator for just about any CPU, it would be excruciatingly slow even on the 40 MHz Quadra 840AV, the fastest 68k Mac ever.

A program such as Wish I Were would do you no good – identifying itself as a PowerPC Mac would not make a 68040-based Mac capable of running PowerPC software.

Is a Mac IIcx Adequate for Shared Internet Access?

ABV writes: I have been reading with interest your Mac Daniel articles. I have read through most of your articles and would like to get your opinion on an upgrade I am considering.

I am setting up a small office network of five Macs with intermittent 56k dial-out access to a local ISP. All of the Macs will be networked via ethernet. I need one machine to act as a router/gateway to the Internet using IPNetRouter. My question for you centers around which computer to use as the gateway. Presently, I am considering two options and would like to hear your thoughts on them.

  1. Use an existing Mac IIcx running Mac OS 7.5.5 and OT 1.1.2. Cost: $70 for 10Base-T NuBus card from Macally.
  2. Purchase a used Power Mac 7500 and setup with Mac OS 8.x. Cost: ~$600 for used 7500 system. ~150 for used 15″ monitor*. Total: ~750.* Note: portrait monitor for Mac IIcx uses a NuBus video card.

My main concern with the Mac IIcx is throughput. According to the articles I read on your site, I will have to use FreePPP in order to see the advantages of a 56k modem on a 68030 processor. Using Apple’s OT PPP and their modem driver would essentially limit a 56K modem to 28.8 speeds. Is this right?

Other considerations:

  1. 10/100 ethernet NuBus cards cost ~$230, so upgrading to a faster network would be more costly, as opposed to 10/100 PCI cards, which currently cost $55.
  2. The Mac IIcx does not support anything higher than Mac OS 7.5.5 (according to Apple Spec database). I believe this limitation stems from the 24-bit addressing built into the Mac IIcx. 32-bit addressing can be accomplished, but only through software. So this machine will not be able to take advantage of any networking enhancements made to future Mac OS releases of TCP/IP. In addition, later versions of Mac OS are more stable than Mac OS 7.5.5.
  3. The 7500 will be able to run OT PPP instead of FreePPP. It has been my experience that the Mac OS and other thidrd party applications complain less when working with OT PPP as opposed to FreePPP. Furthermore, should I have any problems with the 56k modem, the modem manufacturer will most likely instruct me to switch to Apple’s OT PPP, which will then reduce serial thruput to 28 kbps, right? So, the Power Mac 7500 should be more software/hardware compatible than the Mac IIcx

What do you think?

Mac Daniel writes: This one hits close to home. We have more Macs than people in the house (I collect ’em). I want to set up a computer room with ethernet, LocalTalk for the older Macs, and a shared Internet connection. Ideally this would be a cable modem or DSL, but neither have reached Michigan’s second largest city yet. ISDN is costly, but it may be worth it.

Regardless, I’m going to need to share that connection with several Macs. The easy solution would be to buy a Netopia router and let it do all the hard work, but that’s about $900. I may have to go that way eventually so I can have several static IP addresses, but I’d rather find a less costly solution.

IPNetRouter comes highly recommended. I’ve used Vicom Internet Gateway, but that’s a pretty expensive package. IPNetRouter sounds just right.

Because you intend to use a 56k modem, I wouldn’t recommend anything less than a Mac IIfx or Quadra. These models provide enough serial port throughput to really take advantage of the modem’s potential – a IIcx doesn’t. (And, as I’ve mentioned earlier, you don’t want to run Open Transport on a 68030-based Mac, not even the IIfx.)

I would also recommend using Mac OS 8.1, which rules out the IIfx. [Not necessarily – see our later articles on Born Again.] Not only does 8.1 have better Open Transport than earlier versions, it is also more efficient on 68040-based Macs because Apple no longer had to worry about 68030 support. Overall, a Quadra with Mac OS 8.1 is a very stable, relatively fast platform.

Best of all, the bottom seems to have dropped out of the low-end market, leaving some incredible deals for low-end users. For instance, I bought a Quadra 650 24/250 for $150 not too long ago. It makes a great Web and mail server. That, a Centris 650, or a Quadra 800 would make an excellent router for your network. Another advantage these have over the Mac II series is that they already have one ethernet port on the motherboard, although it requires an AAUI adapter.

So my vote is $125-200 for a used Quadra 650 (or sibling), $40 for an AAUI ethernet adapter, and about $40 for a copy of Mac OS 8.1. These models will directly support your portrait monitor. Or you could save money on a monitor and keyboard by using a MoniSwitch to share them between two to four Macs. (That’s what I do.)

That’s serious low-end computing.

Reader Feedback

TK writes: I read this and have a better option . . . at buycomp.com you can purchase a Netgear RM356 (a modem 56k/router/DHCP server/hub) for $249. This is the absolute best bet because the overhead of the PPP connection is in the processor of the Netgear router/modem instead of the Macintosh. All you need to do is put all the Macs on ethernet and TCP/IP on the 192.168.0.x un-net-routable network. The Netgear acts as the gateway/router in the TCP/IP settings. You get static IPs, 56k access, no PPP overhead, and a neat little blue hub too!

CB writes: That reader should consider the Sonic Systems Bandit <http://www.sonicsys.com/Internet_Access/index.html>. It provides three serial ports and a 4-port hub. We have had good success with it. You can have the Bandit combine the throughput of up to three modems to give you increased Internet bandwidth. It’s about $365 to $395.

Keywords: #internetsharing

Short link: http://goo.gl/GfYkF9