Chip ID bits

alexh · 12 February 2008, 15:12

Which registers contain the chip set ID bits?

Code:

Normal PAL Agnus (id=$0000)
Normal NTSC Agnus (id=$0010)
ECS PAL Agnus (id=$0020)
ECS NTSC Agnus (id=$0030)

vposr[13:8]?

Code:

Normal Denise (id=$00FF)
ECS Denise (id=$00FC)

alexh · 12 February 2008, 15:21

Ah, found some info:

http://www.winnicki.net/amiga/memmap/VPOSR.html

meynaf · 12 February 2008, 15:53

You may also have a look at the DENISEID/LISAID register :
http://www.winnicki.net/amiga/memmap/LISAID.html

alexh · 12 February 2008, 16:00

I wondered why I couldn't find anything in the MiniMig code. It doesn't exist

meynaf · 12 February 2008, 16:13

This register first appeared in ECS, it doesn't exist in OCS. This might explain why you didn't find it

alexh · 12 February 2008, 16:37

I was only really looking at the Agnus.

I want to try show people how they can change the MiniMig verilog code to represent an NTSC Amiga.

Why?

MiniMig in PAL configuration will cause so many headaches with it's 50Hz vertical refresh. Most LCD's have a vertical refresh range of 56Hz-75Hz and it just wont work.

The changes are very minimal. This change to the VPOSR register, change of main clock frequency, change of the BEAMCON counters to NTSC constants.

I suggested almost all the necessary changes way back in July, this was the last one (?) I never got round to looking up.

http://www.opencircuits.com/Minimig_NTSC

Personally I am not that bothered, cos I don't have a MiniMig FPGA board.

12 February 2008, 15:12	#1
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,460	Chip ID bits Which registers contain the chip set ID bits? Code: Normal PAL Agnus (id=$0000) Normal NTSC Agnus (id=$0010) ECS PAL Agnus (id=$0020) ECS NTSC Agnus (id=$0030) vposr[13:8]? Code: Normal Denise (id=$00FF) ECS Denise (id=$00FC) Last edited by alexh; 12 February 2008 at 15:19.

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12 February 2008, 15:21	#2
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,460	Ah, found some info: http://www.winnicki.net/amiga/memmap/VPOSR.html

12 February 2008, 15:53	#3
meynaf son of 68k Join Date: Nov 2007 Location: Lyon / France Age: 51 Posts: 5,355	You may also have a look at the DENISEID/LISAID register : http://www.winnicki.net/amiga/memmap/LISAID.html

12 February 2008, 16:00	#4
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,460	I wondered why I couldn't find anything in the MiniMig code. It doesn't exist

12 February 2008, 16:13	#5
meynaf son of 68k Join Date: Nov 2007 Location: Lyon / France Age: 51 Posts: 5,355	This register first appeared in ECS, it doesn't exist in OCS. This might explain why you didn't find it

12 February 2008, 16:37	#6
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,460	I was only really looking at the Agnus. I want to try show people how they can change the MiniMig verilog code to represent an NTSC Amiga. Why? MiniMig in PAL configuration will cause so many headaches with it's 50Hz vertical refresh. Most LCD's have a vertical refresh range of 56Hz-75Hz and it just wont work. The changes are very minimal. This change to the VPOSR register, change of main clock frequency, change of the BEAMCON counters to NTSC constants. I suggested almost all the necessary changes way back in July, this was the last one (?) I never got round to looking up. http://www.opencircuits.com/Minimig_NTSC Personally I am not that bothered, cos I don't have a MiniMig FPGA board.

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