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Conference hydra::amiga_v1

Title:	AMIGA NOTES
Notice:	Join us in the NEW conference - HYDRA::AMIGA_V2
Moderator:	HYDRA::MOORE

Created:	Sat Apr 26 1986
Last Modified:	Wed Feb 05 1992
Last Successful Update:	Fri Jun 06 1997
Number of topics:	5378
Total number of notes:	38326

506.0. "A2000 with 1.5MB ?" by GVAADG::DWANJA () Tue May 19 1987 06:39

Need help to add 512K to my A2000.

In the A2000 there is 512K on the main board and a 1MB board filled with 512K.
So you can add another 512K. Which I have done, but the system keeps telling
me it finds only 1MB and NOT 1.5 MB.

I thought the system would auto check to find out how many memory there
is in. But it does not work.

Should I use AddMem or something else...

Any help is welcome. Thanks in advance.

			
                        Daniel WANJA

T.R	Title	User	Personal Name	Date	Lines
506.1	Ask this guy !	CESARE::ZABOT	Marco Zabot-Adv.Tech.mgr-Turin ACT	`Mon May 25 1987 12:13`	32
	From my collection! If you contact him, please post the jumpers map fro the 1MB. We'd like to do it too!. Ciao. ---------------------------------------------------------------------------- From: rpa 1-May-1987 1206 To: Zabot Subj: Amiga 2000 memory questions. Path: decwrl!pyramid!ctnews!sri-unix!sri-spam!rutgers!mit-eddie!gatech!seismo!mcvax!ukc!eagle!rpa Organization: Computing Lab, University of Kent at Canterbury, UK. Hi Everyone. Excuse me, this is my first posting to the net. Ive got an Amiga 2000, and have had it for about 3 Weeks now. Im in the United Kingdom, and have the German built machine not the West Chester design. .... (omissis) ... Anyway, on opening up my machine, i find that there is a board in the processor slot, this contains 0.5Mbytes of ram, and a further 0.5Mbytes of empty sockets. The main board only contains 0.5Mbytes ram. Almost the first thing i did was to go buy 16 * 256k D-ram chips and plug them into the empty sockets, and play about with the jumpers on the board until the extra .5Mbytes appeared. I found out that the ram was mapped at C00000 to CFFFFF using ROMwack and a terminal. .... ( omissis) ... Richard Almeida.
506.2	Jumper configuration for 1.5MB A2000	GVAADG::DWANJA		`Mon May 25 1987 13:31`	22
	Re : .0 After reading some magazines, I found out how to add the 512k : The card is pluged in the MMU connector(86pins like the one in A1000) which adress is always C00000. But on the card they are five jumpers. To signal that the card is a 512k card they must be OFF ON ON ON OFF To signal that the card contain a Megabyte they must be OFF ON OFF OFF ON. I don't know the meaning of the jumpers but it works. This allow to extend the Amiga 2000 to 1,5 for only the price of 16 256kbit chips. That's great... Daniel W.
506.3	I got me some chips	NWGEDU::RAIJMAKERS	You trace 'm, I make 'm	`Mon Mar 06 1989 11:30`	14
	Hi, I added 16 256k chips to my mem board and configuered the jumpers as shown in re.2 but there's a problem somewhere. I can write to the new memory, but I can not read from it !! (a reset when I acces it) The chips I used have an 120nsec. acces time. Is this the problem? What's the speed of the original chips? Is there a way to make them work with the new ones? Please help!
506.4	120ns is fine	TLE::RMEYERS	Randy Meyers	`Mon Mar 06 1989 21:24`	7
	Re: .3 > The chips I used have an 120nsec. acces time. Is this the problem? > What's the speed of the original chips? I don't think that that is a problem. I think chip faster than 150ns (probably what Commodore uses) is OK.
506.5	Randy, you restored my hope !	NWGEDU::RAIJMAKERS	You trace 'm, I make 'm	`Thu Mar 16 1989 09:02`	16
	Thanks for the reply, Randy. It encouraged me to keep on trying. Searching through memory I noticed several faults appearing on a regular basis all over the new 512kb. In order to make it work I had to 'piggybag' three extra chips. It makes no difference where I put the extra chips, but without them my errors return. I don't know why this works, but it does. Did anyone else have this same problem, or do any of you guys have an explanation for this solution ? Thanks for your info, greetings from Harrie R.(the Ray-Maker)
506.6	Piggy back what chips???	HPSTEK::SENNA		`Thu Mar 16 1989 09:21`	3
	Can you explain the problem and solution in more detail please? I think being sick has corrupted my brain cells!
506.7	The whole story	NWGEDU::RAIJMAKERS	You trace 'm, I make 'm	`Fri Mar 17 1989 04:56`	38
	I added 16 256kb mem. chips to the 1mb board, which was half filled. Then I set the jumpers on that board so the A2000 saw 1.5mb. The new memory adresses go from c80000 to cfffff. So far no problem! I could write data to that part of memory, but reading it back gave problems. In order to find out what was wrong I occupied the memory with zero's (I used cmon, $ O c80000 cfffff 00). Reading the mem. gave somethin like this: C80000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0f 00 00 00 00 00 00 aa 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 1e 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0f 00 etc. So there were flaws and they returned in the same patern all over the new 0.5mb . However, when I put an extra 256kb chip over one of the other 16 the amount of flaws decreases dramaticly. Adding 2 more gave a perfect result. I tested it several ways, copying parts of mem. to other parts and back, but the errors did not return. It makes no difference on wich of the 16 new chips I put the 3 extra ones (--===----------- or -------===------ etc.) the result is always the same. I hope I elaborated enough on the subject, but if you still have any questions, please ask. Greetings, Harrie R.