douglee@doug.UUCP (Doug Lee) (02/04/90)
seamus@bucsf.UUCP (Jeff Rizzo) writes: >A question for the net... I've heard folks say it can be done, but how >do I get my A500 (it has the 1 Meg Agnus) to recognize the extra 512K >expansion (similar to the A501) as chip RAM? > I would appreciate it if someone could email me a description of the >procedure... What you have to do is connect the A19 pin on the fat agnus chip to the A19 line of the CPU chip. It's presently connected to A23. The other thing you have to do is cut the trace between pin 32 of the GARY chip and the expansion ram connector. Cut it towards the connector as you do NOT want to disconnect the pullup resistor from pin 32 of the Gary chip. There may be jumpers for one or both of these. Some versions of A500 have a jumper labelled JP2 which may be moved to change A23 -> A19. This jumper is labelled J101 on many B2000's. The 2000's also have a jumper position labelled J500 which actually has a solder trace between it. This must be cut. You could place jumper pins here later to make it easy to switch Agnus chips. > Thanks in advance, You're welcome > Jeff Rizzo > seamus@bucsf.bu.edu -- douglee@becker <<<Doug Lee>>> 416-461-5357
marco@hprnd.HP.COM (Marco Gonzalez) (02/07/90)
oops!
phupp@warwick.ac.uk (S Millington) (02/08/90)
In article <01904.AA01904@doug> douglee@doug.UUCP (Doug Lee) writes: > >seamus@bucsf.UUCP (Jeff Rizzo) writes: > >>A question for the net... I've heard folks say it can be done, but how >>do I get my A500 (it has the 1 Meg Agnus) to recognize the extra 512K >>expansion (similar to the A501) as chip RAM? > >> I would appreciate it if someone could email me a description of the >>procedure... [deleted] >disconnect the pullup resistor from pin 32 of the Gary chip. There may be >jumpers for one or both of these. Some versions of A500 have a jumper [deleted] Yes there are jumpers: I did try to email this but it bounced from the rn reply option! Anyway here goes: If you have the 1meg agnus I am assuming you have a rev6a board, and 1meg fitted - in the A501 slot, I don't know what difference it makes to have the second 512K on the main board, this experience is from a UK A500. Two jumpers need changing: JP2 - between 68000 and the chip to it's right, it is labeled it is initially linked down, towards the front of the case the connection down is cut and re-made to connect up JPA7 - I'm not too sure about this name, but it is the only jumper near, it is right by, the A501 port. it too is initially linked down this link must be cut and left unconnected THIS IS AT YOUR OWN RISK, CHECK THIS IS CORRECT FOR YOUR BOARD. IT WORKED FOR MY REV6A BOARD, I AM NOT RESPONSIBLE FOR YOU DESTROYING YOURS. Incidentally I did not use solder to remake my link - with a 20W iron and being totaly inept at anything smaller than a 555 it didn't seem such a good idea. I used 'Conductive Silver Paint' from Tandy/Radio Shack, I know but I was desperate and no-one else sold it:-) Good luck to anyone who tries this, but remember what a wrong connection can do to a $450 computer, and try and get the exact same info from a few people, or one person you KNOW is correct, before you try anything. Sorry for all the dire consequencies stuff, but I don't want to be the cause of hundreds of dead amigas. Stuart Millington. phupp@poppy.
bscott@pikes.Colorado.EDU (Ben M Scott) (02/10/90)
I recently installed one in my 500, and didn't have too much trouble. I had the instructions from an old post on FIDOnet, and was also given a sheet from Commodore with the chip (in fact, that's ALL I got; it was wrapped in thin foil and NO other packaging! I finally managed to get some used bubble wrap out of the salesman, but it's really amazing why they don't even have boxes). Anyway, I'm sure the actual instructions have been/will be posted to the net so I won't duplicate it, but I can give some per sonal experience notes: One, the jumpers are a LOT more durable than one would expect; I had a sharp X-acto knife and had to spend several seconds really sawing before I cut through. Second, a tip: be sure not to have any static charges on you while working inside the machine. A good way to assure this is to spray some anti-static monitor spray on your fingers first. Also, I didn't at the time have a soldering iron and so I just taped a little big of foil over the jumper; it worked fine! For about 8 hours... then the pretty green "hardware failure" GURU. After that, I got a friend to solder it for me, and have had no troubles since. Note that you must use Setpatch r if you want the RAD: device to reboot, and this in turn causes problems with VirusX 4.0 until you use the r option of it as well. Note that the old chip is VERY difficult to remove, and the new one is almost as hard to insert afterwards as well. If you can, get a tool for it. I damaged my old chip on removal; you really have to use a lot of force. . <<<<Infinite K>>>>
darrell.grainger@canremote.uucp (DARRELL GRAINGER) (02/11/90)
For those who don't have the latest Rev board (A500) they should be able to still find the JP2 jumper between the 68000 and the Kickstart ROM (that is the chip to the right of the 68000). This jumper/trace should look something like the following: ----- | | | 3 | | | ----- ----- | | | 2 | | | ----- | ----- | | | 1 | | | ----- What you need to do is cut the connection between pad 1 and 2 plus solder together pad 2 and 3. On many of the board you will not find the jumper for pin 32 of the Gary chip. To cut the circuit from the Gary chip to the A501 I would recommend taking the Gary chip out of the socket, bend up pin 32 and put the Gary back into its socket. Darrell P.S. to the receiver of this message: I know you know how to do the install but for others reading the message I thought I'd add what to do if the Gary/pin 32 cut was not obvious. --- * Via ProDoor 3.1R
rmal@cernvax.UUCP (richard lucock) (02/20/90)
Previous notes on the fat Agnus have just referred to the A500. I have a 2000 (a week or two old) on which I ran the ECStest program (Enhanced Chip Set test, can't remeber who wrote it); it told me that I had the new Agnus, but that the operating system didnt know about it. Since the basic 2000 seems to come with 1 meg of RAM, this seems a bit strange. Anyone know anything about this ? And how to make the agnus know about *all* memory available ? Thanks, Richard
hart@ug.cs.dal.ca (Todd Darrell Raymond Hart) (02/22/90)
I have an A500 and have just recently tried the ECSTest. Well it replies that I have a NORMAL AGNES (NTSC?) which is what I expected as my maching is about a year old. But lookout Denise, the program just can't seem to make up its mind, one try it says NORMAL and the next it could say SUPER (OS does not know), I tried several times and it seems close to 50/50 for the choice. What is going on here, how come the ECSTest can't make up its mind, anyone have any answers?!? Todd. [ MAIL: HART@UG.CS.DAL.CA ]
rmal@cernvax.UUCP (richard lucock) (02/23/90)
On the subject of whether the amiga is aware of the Fat Agnus, it seems that ECStest doesn't tell you whether Agnus is aware of all 1Meg of memory, but the avail command does. My thanks to people who sent email. (I should have know about the AVAIL command already, but although I ordered an english language manual set, Commodore sent me a german AmigaDos Manual. Since I live in the French speaking part of Switzerland, this is some achievment !). Richard