Re: System identification from Applesoft?

[Benoit0123 <bgilon@free.fr>]

Antoine Vignau wrote:
> Le mercredi 13 février 2013 23:42:20 UTC+1, Antoine Vignau a écrit :
>> Benoît,
>> 
>> what is the need to switch to pure 16-bit before calling IDROUTINE?
>> 
>> av
> 
> I mean, 18 20 1F FE 90 IIgs or B0 notIIGS (sorry), should be sufficient to
> differentiate //e from IIgs.
> Do we need more? ROM version (in Y), etc. ?
> 
> ...
> 
> Read code, all registers are 16-bit wide but upper byte is not used,
> therefore your code is good.
> 
> ...
> 
> I've learned something today, thank you :-)
> 
> av
Hello Antoine,

I extracted this short routine from a program utility I wrote in the past
(in the 80/90s last century) while visiting a friend just having purchased
its ROM01 //gs just to test the program features on the new //gs hardware...
I remembered that only Yreg was useful for me as output, and that Y result
value code could make possible a post //gs machine possible (hi byte being
non zero: I do not know whether the would be "Mark Twain" CPU just updated
the ROM version to 4 or increased the high byte too, to mark it as a
hardware new architecture).

Regards,
Benoît

> * Identification bytes for CORTLAND
> *
> * REGIDz's are return'ed when the user JSR's to $FE1F.
> *
> * REGIDA = Bit 15 = reserved
> *          Bit 14 = reserved
> *          Bit 13 = reserved
> *          Bit 12 = reserved
> *          Bit 11 = reserved
> *          Bit 10 = reserved
> *          Bit 09 = reserved
> *          Bit 08 = reserved
> *          Bit 07 = reserved
> *          Bit 06 = 1 if system has a memory expansion slot
> *          Bit 05 = 1 if system has an IWM port
> *          Bit 04 = 1 if system has a built in clock
> *          Bit 03 = 1 if system has front desk bus
> *          Bit 02 = 1 if system has SCC built in
> *          Bit 01 = 1 if system has external slots
> *          Bit 00 = 1 if system has internal slots
> *
> * REGIDX = Bit 15 = reserved
> *          Bit 14 = reserved
> *          Bit 13 = reserved
> *          Bit 12 = reserved
> *          Bit 11 = reserved
> *          Bit 10 = reserved
> *          Bit 09 = reserved
> *          Bit 08 = reserved
> *          Bit 07 = reserved
> *          Bit 06 = reserved
> *          Bit 05 = reserved
> *          Bit 04 = reserved
> *          Bit 03 = reserved
> *          Bit 02 = reserved
> *          Bit 01 = reserved
> *          Bit 00 = reserved
> *
> * REGIDY = Bit 15-8 = machine id byte
> *                  0 = Cortland
> *                  01-FF = future systems
> *          Bit 07 = 0
> *          Bit 06 = 0
> *          Bit 05 = 0
> *          Bit 04 = 0         Bits 00-07 = ROM version number
> *          Bit 03 = 0
> *          Bit 02 = 0
> *          Bit 01 = 0
> *          Bit 00 = 1   
> 
> REGIDA		DC.W	$007F	;Register identification byte
> REGIDX		DC.W	$0000	;Register identification byte
> REGIDY		DC.W	$0003	;Register identification byte
>