hugh@hcrvx1.UUCP (Hugh Redelmeier) (10/18/85)
A month ago, I asked for details about what a disk looks like
to an Atari 600xl computer. Here are some things I have learned
since then.
The Atari 800 series does indeed talk to its peripherals at 19.2K
on an asynch serial line. The levels are TTL, not RS232C.
On SIG/M disk 171, there is a file "ATARIBUS.LBR". This is a
collection of programs that make a CP/M-80 machine look like
several Atari disk drives. SIG/M is the major publisher of
public-domain CP/M programs; their disks are widly available,
often from "RCP/M" systems (lists of RCP/M systems pass through
usenet frequently). The ataribus system is written in BDS C.
Source and (patchable) binaries are provided. And instructions
on how to use it.
The ataribus documentation suggests dealing with the TTL level
problem by bypassing your CP/M system's level converters
(probably 1488 and 1489 chips). I don't like this, so I am
going to try to build a level converter for my Atari. I am
hoping that the Atari connector provides +/-12V.
Hugh Redelmeier (416) 922-1937
{utzoo, ihnp4, decvax}!hcr!hugh