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Old 4th May 2019, 10:31 pm   #14
john_newcombe
Pentode
 
Join Date: Apr 2019
Location: Skipton, North Yorkshire, UK.
Posts: 175
Default Re: Gemini 80-Bus System

John; Firstly many thanks for the disk definitions, much appreciated.

I am wondering if someone can confirm my understanding of how this all fits together.

As far as I understand, the DPB's form part of the customised CP/M (Bios) and provide support for the various types of disk drive that can be connected to the machine under CP/M.

This being the case I am assuming that any machine booting up using RP/M or any other monitor has no knowledge of the connected disk type, only that it should get the boot program from the fist sector on the first track. I am also guessing that this program is familiar with the drive type somehow and knows how to load the bios, bdos, ccp etc. or am I way off?

I am left with a few questions e.g.

* How does the CP/M system know which drive type is connected during the boot process?
* How does the CP/M system know which DPB to use, once CP/M is up and running?

I am sorry if this is a real newbie question, but I have searched the internet and the odd CP/M books I have here, and am a little confused.
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