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General Category => Other retro => Topic started by: beaker on 16:17, 22 March 20

Title: Amstrad PC 2286 Help
Post by: beaker on 16:17, 22 March 20
Can anyone help, I need a user manual for the Amstrad 2286/2386 PC, or can anyone scan the jumper settings needed to change from the chip RAM to using SIMMS if anyone has one?

A little background, I am in the process of restoring an old broken Amstrad 2286 (just as a little project). So far I've changed the PSU over as it kept blowing the fuse on the main plug whenever switched on, cleaned up all the dirt and corrosion, replaced the VGA connector as it wasn't outputting a signal, sourced a keyboard and broken monitor (one for a later date). Now it's trying to boot but getting a parity error message when booting from the chip RAM. As I understand it, I need to remove the 1MB on board chip RAM (12 chips in sockets) and can use 30 pin parity RAM of the 9 chip persuasion. As I plan to upgrade the RAM as I have 2x 4MB SIMMS in my parts bin so there's not much point trying to work out which chip RAM chip(s) have failed.
Title: Re: Amstrad PC 2286 Help
Post by: Bryce on 20:16, 22 March 20
I'll need to take a long look tomorrow to find the jumper settings, but you don't need to physically remove the on board RAM, just change the jumper settings.

Title: Re: Amstrad PC 2286 Help
Post by: beaker on 20:37, 22 March 20
Thanks Bryce, that would be brilliant.

I did come across an old post on Cliff Lawson's website regarding the upgrade and he mentioned jumpers and that the chips had to be removed otherwise strange things start happening... I assume Amstrad cut a few corners  :laugh:
David Cefai (davcefai@keyworld.net) in Malta at 21:2:23 Monday October 20 97
 I'm trying to increase RAM on a PC2286. Step 1, replace the original chips by 4x256K SIMMS salvaged from an old Epson PCAX3 - 80ns, 3 chips,2 large one small, worked OK. Step 2, I tried 4x1MB non parity checked SIMMS - no go! Parity error. Step 3, bought 2x1MB parity checked SIMMS (3 chips all same size) - the PC wouldn't boot. Jumpers were definitely set as per the manual. Question: (1) What type SIMMs will work? (2) can I turn off Parity checking?
 Amstrad answers: Err you didn't mention about having removed the 12 socketed chips on the 2286 board that provided the original 1MB. They MUST be removed before you start adding SIMMs or you'd get exactly the sort of problems you describe. 3 chip SIMMs may well work but the 2xxx machines were designed in the days of 9chip SIMMs so only they can be guaranteed to work. They MUST be parity checked as there is NO way to switch off parity checking in the PC design.
Title: Re: Amstrad PC 2286 Help
Post by: Bryce on 10:17, 23 March 20
Oh, didn't know that. They really cut every corner possible!