Re: Help with IIGS Slot Register $C02D

[Hugh Hood <hughhood@earthlink.net>]

Antoine,

Thanks for posting the listing of the various $C02D bits from the IIGS
Firmware Reference. It's more instructive than my rambling narrative and may
spur others who were not previously aware to try the technique for printer
switching purposes.

I modify (either clear or set) bit 1 to switch between a parallel printer
card and the internal serial port in slot 1.

I've found I can switch back and forth (and back) without problem provided
the slot is initially set in the Control Panel to the internal port. If it's
initially set to 'Your Card', I experience trouble (no output).

I will look into the misc tool set calls you mention, but first I think I'll
try to 'tickle' $CFFF to see if it has something to do with the $C800-$CFFF
expansion ROM space.

Maybe the IIGS internal serial port firmware uses this area and is not
seeing it when needed, whereas my simple Epson APL parallel card does not.

Thanks again for the input.




Hugh Hood



 

in article 
3ea37f2c-af12-4b9e-b985-f423e1d92012@v20g2000yqb.googlegroups.com, Toinet at
antoine.vignau@laposte.net wrote on 10/31/10 1:33 PM:

> Hi Hugh,
> 
> several questions and ideas:
> - ROM 1 or ROM 3?
> - The def of $C02D:
> 
> * __7______6______5______4______3______2______1______0___
> *|      |      |      |      |      |      |      |      |
> *|Slot7 |Slot6 |Slot5 |Slot4 |      |Slot2 |Slot1 |      |
> *|intext|intext|intext|intext|   0  |intext|intext|   0  |
> *|enable|enable|enable|enable|      |enable|enable|      |
> *|______|______|______|______|______|______|______|______|
> *               ^^^^^  SLTROMSEL Byte ^^^^^
> 
> * SLTROMSEL bits defined as follows
> *    bit 7= 0 enables internal slot 7 -- 1 enables slot ROM
> *    bit 6= 0 enables internal slot 6 -- 1 enables slot ROM
> *    bit 5= 0 enables internal slot 5 -- 1 enables slot ROM
> *    bit 4= 0 enables internal slot 4 -- 1 enables slot ROM
> *    bit 3= MUST be 0
> *    bit 2= 0 enables internal slot 2 -- 1 enables slot ROM
> *    bit 1= 0 enables internal slot 1 -- 1 enables slot ROM
> *    bit 0= Must be 0
> 
> SLTROMSEL  EQUDS.B 1 ;Slot ROM select
> 
> - Have you tried the misc tool set calls to get/set values from the
> firmware?
> 
> antoine