CP/M-86 for IBM PC and XT version 1.1 on a 8088

[Klee]

I was diagnosing my Beltron XT clone mb , it turned out to be a mounting screw shorting one trace to ground , and as it was booting up I grabbed a boot floppy .

I was thinking it was my MS Dos 6.22 360k boot disk but as it was booting I realized I grabbed the wrong one.

It booted anyway and works just fine on a 8088 XT clone mb .

Whats the deal , I thought CP/M 86 needed at least a 8086 cpu.:huh:

 

[SteveH]

Whats the deal , I thought CP/M 86 needed at least a 8086 cpu.:huh:

The 8086 and 8088 belong to the same family and use the same instruction set. The difference being they way they talk to their peripheral chips; the 8086 has a full 16 bit data bus and the 8088 has an 8 bit [multiplexed?] data bus.

 

[per]

The 8086 and 8088 belong to the same family and use the same instruction set. The difference being they way they talk to their peripheral chips; the 8086 has a full 16 bit data bus and the 8088 has an 8 bit [multiplexed?] data bus.

It's not even fully multiplexed. The 8088 is only 8 bits externally, and it will therefore work much like any 8-bit CPU interface-wise. However, the core and instruction set is fully 16-bit, and it will therefore have just the same execution capabilities as the 8086.

In other words, from the perspective from software; the 8088 is a fully 16-bit CPU. From the perspective from hardware; the 8088 uses an 8-bit interface.

 

[Klee]

Ok now I get it.

I'm planing on running CP/M 3.0 but I have no boot CP/M boot disk so can I use CP/M 86 as a working enviroment to create a CP/M 3.0 running system?

 

[Chuck(G)]

Possibly, but you'd be just as well off using MS-DOS--better tools.

 

[JohnElliott]

The nearest equivalent for PC compatibles is Personal CP/M-86 version 2.0/4. While there is a CP/M-86 Plus, I'm not aware of a copy with a PC-compatible XIOS.