19 March 2008, 07:24 | #1 |
Registered User
Join Date: Feb 2007
Location: Sydney, Australia
Posts: 54
|
Trapdoor expansion options for A500
Hi all,
Over the last couple years I've been collecting various bits for the A500s i plan to setup again. Currently I have a few A500s, Action Replay carts, (Mk I,II, and III), the ICD adIDE adapter (lets you autoboot IDE hard drive from the A500), and a Chip-Ex B/ MegaChip (I think that's what it's called - 8375 agnus with 1.5mb or 2mb ram). I was after a decently sized trapdoor expansion (assuming it works with the Chip-Ex), but can't them anywhere (new or 2nd hand). How big could they get without the need for loading up custom drivers? At the moment I have a couple 512kb expansions but remember when i bought my a500 that 2mb expansions were available. Thanks, Impakt Last edited by Impakt; 19 March 2008 at 11:02. |
19 March 2008, 10:29 | #2 |
Thalion Webshrine
Join Date: Jan 2004
Location: Oxford
Posts: 14,561
|
Trapdoor expansions can be 512Kbytes on regular A500 and 1Mbyte on A500+
Anything over that and they have to connect to something else as well as the Trapdoor connector (e.g. the 68000 or Gary) because there are not enough address lines etc. |
19 March 2008, 11:03 | #3 |
Registered User
Join Date: Feb 2007
Location: Sydney, Australia
Posts: 54
|
Thanks for the response. After doing a bit of searching around here this evening, I noticed that the Chip-Ex is basically exactly the same as the Megachip.
Hopefully this mod will be compatible with a big trapdoor expansion. My aim is to setup an Amiga 500 with internal hard drive, action replay, and heaps of ram.. |
19 March 2008, 11:25 | #4 |
Thalion Webshrine
Join Date: Jan 2004
Location: Oxford
Posts: 14,561
|
Try and get an accelerator instead.
Viper A520 / A530 VXL030 etc. |
19 March 2008, 18:17 | #5 |
-
Join Date: Jul 2003
Location: Helsinki / Finland
Age: 43
Posts: 9,944
|
Make sure you get the manual when you install your big ram board.. You will need to carefully configure it to avoid duplicating RAM in any memory address.
|
20 March 2008, 01:01 | #6 |
Registered User
Join Date: Feb 2007
Location: Sydney, Australia
Posts: 54
|
So what's the most amount of ram i could hope to get in the a500 by only using the trapdoor slot and the Megachip?
Any shops still selling > 0.5mb expansions or is eBay my only option? Are there any schematics on making your own expansion? Thanks! Impakt |
20 March 2008, 05:08 | #7 | |
I hate potatos and shirts
|
Quote:
Other memory will be added as FAST RAM, if you grab an accelerator or an A590 (plus 8Mb RAM). |
|
20 March 2008, 06:05 | #8 |
hastala vista winny vista
|
Megachip is for increasing Chip ram. It can be maximum 2 mb.
Trapdoor slot AFAIK adresses a memory range called 'ranger memory'. it is normally 512k, but with a gary adapter you can have 1.8 mb fast ram there. So that maximum you can get with chip ram adapter and trapdoor expansion slot is 2mb chip + 1.8 mb fast (with gary adapter). Note that on A500+ the trapdoor slot is used to increase chip mem, so you probably can't have fast mem cards there (somebody correct me). Also please note that AR is made with a basic unexpanded A500 configuration in mind. Some expansions may create conflicts with it. Also it doesn't even work with any kickstart over 37.299 (conflicts with gayle adresses ?) Finally A590 gives you 2mb fast ram, not 8 (but yeah lots of other harddisk controllers do give 8mb fast ram). |
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
Thread Tools | |
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
WTB: Amiga 500 Expansion Card Trapdoor | sorfri2 | MarketPlace | 3 | 03 January 2013 10:02 |
Another A1200 trapdoor expansion | mikele | MarketPlace | 3 | 09 May 2012 15:14 |
Wanted: A601 1MB Trapdoor Expansion | Solid Snake | MarketPlace | 7 | 06 January 2012 19:38 |
A500 Plus Trapdoor Expansion | TheCorfiot | support.Hardware | 10 | 14 March 2008 16:42 |
Removing a trapdoor expansion | numb | New to Emulation or Amiga scene | 14 | 08 March 2005 23:40 |
|
|