68K Macs with MacOS 7.5 still in production use...

Norman Jaffe turing at shaw.ca
Thu Sep 15 13:28:31 CDT 2016

And, to 'put a nail in it', the bitsavers file for the MC68000 is '68000_16-Bit_Microprocessor_Apr83.pdf'. 
----- Original Message -----

From: "Chuck Guzis" <cclist at sydex.com> 
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> 
Sent: Thursday, September 15, 2016 11:24:11 AM 
Subject: Re: 68K Macs with MacOS 7.5 still in production use... 

On 09/15/2016 11:03 AM, Peter Corlett wrote: 
> On Mon, Sep 12, 2016 at 01:40:56PM -0700, Chris Hanson wrote: 

>> No, the 68000 was a 32-bit CPU, as defined by the register width 
>> and programming model. The fact that it was implemented with a 
>> 16-bit ALU and had a 16-bit data path to memory is immaterial. 
> By that logic, the Z80 is a 16 bit processor because ADC HL, BC and 
> the like exist. It even has a 4 bit ALU and passes data through 
> twice, but this is an invisible implementation detail and it's 
> generally considered to be an 8 bit CPU. Likewise, the existence of 
> zmm0-zmm31 registers don't mean that contemporary x86 is 512 bit. 

My 68K manual, as handed to me by the Moto sales guy at Wescon back in 
the day says "MC68000 16-BIT MICROPROCESSOR User's Manual". Page 1-1 
reiterates essentially the same sentiment: 

"The MC68000...combines state-of-the-art technology and advanced circuit 
design techniques with computer sciences to achieve an architecturally 
advanced 16-bit microprocessor." 

Call it anything you want, but we know what Motorola called it. 


More information about the cctalk mailing list